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Background: Thrombocytosis, often considered a marker of normal inflammatory reaction of infections, has been recently associated with increased mortality in hospitalized patients with community-acquired pneumonia (CAP). We assessed the characteristics and outcomes of patients with CAP and thrombocytosis (platelet count ≥ 4 × 105/mm3) compared with thrombocytopenia (platelet count < 105/mm3) and normal platelet count., Methods: We prospectively analyzed 2,423 consecutive, hospitalized patients with CAP. We excluded patients with immunosuppression, neoplasm, active TB, or hematologic disease., Results: Fifty-three patients (2%) presented with thrombocytopenia, 204 (8%) with thrombocytosis, and 2,166 (90%) had normal platelet counts. Patients with thrombocytosis were younger (P < .001); those with thrombocytopenia more frequently had chronic heart and liver disease (P < .001 for both). Patients with thrombocytosis presented more frequently with respiratory complications, such as complicated pleural effusion and empyema (P < .001), whereas those with thrombocytopenia presented more often with severe sepsis (P < .001), septic shock (P = .009), need for invasive mechanical ventilation (P < .001), and ICU admission (P = .011). Patients with thrombocytosis and patients with thrombocytopenia had longer hospital stays (P = .004), and higher 30-day mortality (P = .001) and readmission rates (P = .011) than those with normal platelet counts. Multivariate analysis confirmed a significant association between thrombocytosis and 30-day mortality (OR, 2.720; 95% CI, 1.589-4.657; P < .001). Adding thrombocytosis to the confusion, respiratory rate, and BP plus age ≥65 years score slightly improved the accuracy to predict mortality (area under the receiver operating characteristic curve increased from 0.634 to 0.654, P = .049)., Conclusions: Thrombocytosis in patients with CAP is associated with poor outcome, complicated pleural effusion, and empyema. The presence of thrombocytosis in CAP should encourage ruling out respiratory complication and could be considered for severity evaluation.

This study aims to evaluate the impact of pretreatment thrombocytosis on survival in patients with nasopharyngeal carcinoma (NPC). The data of 1,582 patients with NPC, who underwent definitive treatment between 2003 and 2004, were retrospectively reviewed. The correlation between the clinicopathological variables and the platelet count was analyzed. The prognostic significance of thrombocytosis, together with various clinicopathological factors, was evaluated by univariate and multivariate analyses. Platelet count showed significant correlation with gender, clinical stage, and T stage in univariate analysis. There was poorer 5-year disease-specific survival (DSS) in the patients with thrombocytosis than in those without thrombocytosis (70 vs. 78 %; p = 0.001) and poorer metastases-free survival (MFS) (81 vs. 88 %; p = 0.006). Univariate and multivariate analyses showed that thrombocytosis was an independent prognostic factor for MFS and DSS. Thrombocytosis is a useful predictor of metastasis and poor prognosis in patients with NPC.

The Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs) share an increased risk of thrombotic and hemorrhagic complications. The thromboses are more commonly arterial than venous, but unique to the BCR-ABL-negative MPNs is the involvement of the abdominal veins. Commonly accepted thrombotic risk factors include advanced age and a prior thrombotic episode, although these risk factors are associated with thrombosis regardless of the presence of an MPN. Emerging risk factors may include leukocytosis and presence of the JAK2 V617F mutation or an increase in its allelic burden. Interventions to prevent and/or treat MPN-related thromboses include aspirin, anticoagulation, and cytoreductive therapy. Although phlebotomy is a cornerstone of management in polycythemia vera to lower the risk for thrombosis, the target hematocrit is being reevaluated. Hemorrhagic complications occur with extreme thrombocytosis and may be related to acquired platelet defects such as acquired von Willebrand syndrome. The impact of new mutations and novel therapies, including JAK-inhibitors and interferon, on the thrombotic and hemorrhagic tendency remains to be determined., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Pseudohyperkalaemia that occurs in conditions with raised platelet counts is caused by an in vitro rise of the serum potassium concentration during whole blood coagulation together with lysis of platelets and other cellular components, in the presence of normal renal function and plasma potassium levels. Here, we report the case of a 66-year-old man presenting a myeloproliferative disorder with thrombocythaemia. His serum potassium level was 6.4 mmol/L in the presence of normal renal function (creatinine clearance 78 mL/min) and a normal acid-base balance. Pseudohyperkalaemia in thrombocythaemia was suspected. Our suspicion was confirmed over the following three days by measuring potassium level in both a lithium heparin specimen tube (plasma sample) and in the serum. A clear-cut difference between serum potassium levels (mean 6.27 mmol/L) and plasma potassium levels (mean 4.10 mmol/L) was found. In conclusion, the aim of the present case report is to increase the awareness of the existence of pseudohyperkalaemia occurring in diseases that cause increased platelet counts in order to reduce the risk of potentially harmful treatment.

In the WHO classification, there is a provisional entity called Myelodysplastic/Myeloproliferative Neoplasm, Unclassifiable (MDS/MPN, U). Refractory anemia with ringed sideroblasts associated with marked thrombocytosis (RARS-T) was included in this category. Recently published studies report a small percentage of patients with RARS-T. Sixty percent of these have JAK2 V617F mutation, which can suggest the coexistence of two pathological conditions (MDS and MPN). In this paper, we analyzed three patients diagnosed with RARS-T in the Department of Hematology, "Fundeni" Clinical Institute, Bucharest, Romania, during the period 2005-2011. The patients were investigated with cytogenetic exam and molecular biology. In these three cases were identified morphological features of multilineage dysplasia (two-lineage dysplasia in two cases and three-lineage dysplasia in one case). In two cases, thrombocytosis was under 1000×10(3)/μL and clinical evolution was similar to the myelodysplastic syndrome (transfusion dependent anemia with response to administration of erythropoietin). In the third case, the platelets were over 1000×10(3)/μL and with response to the treatment with Hydrea, which improved anemia. JAK2 V617F mutation was not identified in any case. RARS-T remains a provisional entity and requires a complex investigation of patients for the correct diagnosis of these patients. Therapeutic options should be personalized to each case in part because there is not yet a standardized treatment of these patients.

Platelets promote metastasis and angiogenesis, but their effect on tumor cell growth is uncertain. Here we report a direct proliferative effect of platelets on cancer cells both in vitro and in vivo. Incubation of platelets with ovarian cancer cells from murine (ID8 and 2C6) or human (SKOV3 and OVCAR5) origin increased cell proliferation. The proliferative effect of platelets was not dependent on direct contact with cancer cells, and preincubation of platelets with blocking antibodies against platelet adhesion molecules did not alter their effect on cancer cells. The proliferative effect of platelets was reduced by fixing platelets with paraformaldehyde, preincubating platelets with a TGF-β1-blocking antibody, or reducing expression of TGF-βR1 receptor on cancer cells with siRNA. Infusing platelets into mice with orthotopic ovarian tumors significantly increased the proliferation indices in these tumors. Ovarian cancer patients with thrombocytosis had higher tumor proliferation indices compared with patients with normal platelet counts.

Unlabelled: Study Type - Prognosis (cohort series) Level of Evidence 2a What's known on the subject? and What does the study add? Preoperative thrombocytosis has been identified as a predictor of poor outcome in various cancer types. However, the prognostic role of platelet count in patients with invasive bladder cancer undergoing radical cystectomy is unknown. The present study demonstrates that preoperative thrombocytosis is an independent risk factor for decreased cancer-specific survival after radical treatment of invasive bladder cancer. We developed a new prognostic scoring model for cancer-specific outcomes after radical cystectomy including platelet count and established pathological risk factors. Consideration of platelet count in the final model increased its predictive accuracy significantly. Thrombocytosis may be a useful parameter to include within established international bladder cancer nomograms., Objective: •  To investigate the oncological significance of preoperative thrombocytosis in patients with invasive bladder cancer undergoing radical cystectomy, as it has been reported as a marker for aggressive tumour biology in a variety of solid tumours., Patients and Methods: •  The series comprised 258 patients undergoing radical cystectomy between 1999 and 2010 in whom different clinical and histopathological parameters were assessed. •  Elevated platelet count was defined as >450 × 10(9) /L. •  Based on regression estimates of significant parameters in multivariable analysis a new weighted scoring model was developed to predict cancer-specific outcomes., Results: •  The median follow-up was 30 months (6-116). •  Of the 258 patients, 26 (10.1%) had elevated and 232 (89.9%) had normal platelet count. The 3-year cancer-specific survival in patients with normal and elevated platelet count was 61.5% and 32.7%, respectively (P < 0.001). •  In multivariable analysis, cancer-specific survival was significantly lower in patients with locally advanced disease (≥pT3a) (relative risk 2.91, 1.54-5.65; P= 0.001), positive soft tissue surgical margins (4.03, 1.99-7.92; P= 0.001) and thrombocytosis (2.68, 1.26-5.14; P= 0.011). •  The 3-year cancer-specific survival in patients with a score 0 (low risk), 1-2 (intermediate risk) and 3-5 (high risk) was 81.0%, 54.8% and 8.2%, respectively (P < 0.001). •  Consideration of preoperative platelet count in the final model increased its predictive accuracy by 1.8% with a concordance index of 0.745 (P= 0.040)., Conclusions: •  The presence of thrombocytosis at radical cystectomy portends unfavourable prognosis. •  We constructed a simple weighted prognostic model for cancer-specific outcomes after radical cystectomy based on pretreatment platelet count and established pathological risk factors. •  These data warrant external validation and may allow for tailored monitoring and selection of appropriate patients for neoadjuvant and adjuvant trials., (© 2012 BJU INTERNATIONAL.)

There is a need to improve the prognostic and predictive indicators in non-small cell lung cancer (NSCLC). At present, the main focus is on genetic predictive markers while the prognostic value of the standard blood variables related to haematopoiesis has been subjected to relatively limited attention. To study the prognostic potential of haemoglobin (Hgb), platelet (Plt) and white blood cell (WBC) levels at time of diagnosis in NSCLC patients, 835 NSCLC patients, stage I-IV, who received radiotherapy with curative intention (>50 Gy), were included in the study. WBC, Plt, Hgb, gender, age at diagnosis, stage, surgery and first-line chemotherapy were studied in relation to overall survival. For patients with Hgb < 110 g/L and Hgb ≥ 110 g/L), the median survival was 11.2 and 14.5 months, respectively (p = 0.0032). For WBC > 9.0 × 10(9)/L and < 9.0 × 10(9)/L, the median survival was 11.6 and 15.4 months, respectively (p < 0.0001). For Plt > 350 × 10(9)/L and <350 × 10(9)/L, the median survival was 11.2 and 14.9 months, respectively (p < 0.0001). The median survival in patients with pathological results in all three markers was half of that in patients with normal levels of all three markers (8.0 and 16.0 months, respectively (p < 0.0001). The level of the three studied haematological biomarkers corresponds significantly to outcome in NSCLC. These results indicate that standard haematological variables may be used as guidance for the clinician in the decision-making regarding treatment intensity and patient information.

Celiac disease, an autoimmune disease once thought to be uncommon, is now being increasingly identified. Our improved diagnostic modalities have allowed us to diagnose more and more patients with atypical symptoms who improve on gluten-free diet (GFD). We discuss here the latest findings regarding the various hematological manifestations of celiac disease and their management. Anemia remains the most common hematological manifestation of celiac disease due to many mechanisms, and can be the sole presenting symptom. Other manifestations include thrombocytosis and thrombocythemia, leukopenia, thromboembolism, increased bleeding tendency, IgA deficiency, splenic dysfunction, and lymphoma. The diagnosis of celiac disease should always be kept in mind when a patient presents with unexplained and isolated hematological finding. Once diagnosed, patients should adhere to GFD and be educated about the potential complications of this disease. We herein present an algorithm for adequate management and follow-up.

Objective: To evaluate the influence of preoperative thrombocytosis on survival after surgery in patients with colorectal cancer (CRC)., Methods: Four hundred fifty-three patients who had undergone CRC surgery were retrospectively identified from institutional database. On the basis of receiver operating characteristic (ROC) curve analysis, they were classified into two groups: group A, with a preoperative platelet count of ≤300 (×10(9) /L), and Group B, with a preoperative platelet count of >300 (×10(9) /L). Uni- and multivariate analyses were performed to evaluate the relationship to overall survival. Kaplan-Meier analysis and log rank test were used to compare the survival curves between groups A and B., Results: There was a significant difference in overall survival between the two groups (P = 0.007). Multivariate analysis of selected preoperative clinicolaboratory characteristics showed that overall survival was associated with the platelet count (Group A/B) (odds ratio, 1.642; 95% CI, 1.025-2.629; P = 0.039) as well as the number of tumors (1/≥2), and the serum levels of C-reactive protein (CRP) and carcinoembryonic antigen (CEA)., Conclusion: Preoperative thrombocytosis is associated with survival after surgery in CRC patients, and is able to divide such patients into two independent groups before surgery., (Copyright © 2012 Wiley Periodicals, Inc.)

Background: It is uncertain whether reactive thrombocytosis is associated with an increased risk of venous thromboembolism. This study assessed the incidence of reactive thrombocytosis, defined as platelet count ≥ 500 × 10(9)  L(-1) , at intensive care unit discharge and its association with subsequent venous thromboembolism., Methods and Results: This cohort study involved linkage of routinely collected intensive care unit, laboratory, radiology and death registry data of critically ill patients admitted to the intensive care unit between January 2009 and March 2010. The census date for survival and radiologically confirmed venous thromboembolism was 31 October 2011. Of the 1446 patients who survived to intensive care unit discharge, 139 patients had reactive thrombocytosis (9.6%, 95% confidence interval [CI] 8.2-11.2%). Twenty-nine patients developed venous thromboembolism after discharge (2%, 95% CI 1.4-2.9%; 67 per 100 person-years, 95% CI 45-97) and the median time to develop venous thromboembolism was 25 days (interquartile range 8-148). Reactive thrombocytosis was associated with an increased risk of subsequent venous thromboembolism (hazard ratio 5.3, 95% CI 1.7-16.4), after adjusting for other covariates. Platelet counts explained about 34% of the variability in the risk of venous thromboembolism and had a relatively linear relationship with the risk of venous thromboembolism when the platelet counts were > 400 × 10(9)  L(-1) . Venous thromboembolism after intensive care unit discharge was associated with an increased risk of mortality (hazard ratio 2.0, 95% CI 1.1-3.9), after adjusting for reactive thrombocytosis., Conclusions: Reactive thrombocytosis during the recovery phase of critical illness was associated with an increased risk of subsequent venous thromboembolism., (© 2012 International Society on Thrombosis and Haemostasis.)

Context: Hypercalcemia associated with myelofibrosis is rare, and its pathogenesis and treatment are not known., Objective: We report a unique case of hypercalcemia associated with post-essential thrombocythemia myelofibrosis and review the clinical and laboratory features, pathogenesis, and responsiveness to treatment with the bone antiresorptive agent, denosumab., Results: A 62-yr-old woman with essential thrombocythemia presented with progression to myelofibrosis with lytic skull lesions and symptomatic hypercalcemia. Other causes of hypercalcemia were excluded. Her disturbance in calcium homeostasis was not PTH- or vitamin D-mediated, although this has been postulated in cases of hypercalcemia with the related entity of primary myelofibrosis. Her hypercalcemia was refractory to aggressive iv saline administration, furosemide, calcitonin, and pamidronate, but promptly improved after one 120-mg sc dose of the anti-receptor activator of nuclear factor κB (RANK) ligand monoclonal antibody, denosumab, with sustained normocalcemia for approximately 2 months. She died 6 months later from complications due to the leukemic transformation of her hematological disease., Conclusion: The pathogenesis of myelofibrosis-related hypercalcemia could be due to multiple factors, particularly changes in the RANK ligand-RANK-osteoprotegerin system that lead to increased osteoclast activity. Although we did not measure these factors, denosumab holds promise in the treatment of malignancy-associated hypercalcemia and specifically that related to myelofibrosis. Hypercalcemia associated with myelofibrosis is rare, and its pathogenesis and treatment are not known.

Background: Refractory anemia with ring sideroblasts associated with marked thrombocytosis was proposed as a provisional entity in the 2001 World Health Organization classification of myeloid neoplasms and also in the 2008 version, but its existence as a single entity is contested. We wish to define the clinical features of this rare myelodysplastic/myeloproliferative neoplasm and to compare its clinical outcome with that of refractory anemia with ring sideroblasts and essential thrombocythemia., Design and Methods: We conducted a collaborative retrospective study across Europe. Our database included 200 patients diagnosed with refractory anemia with ring sideroblasts and marked thrombocytosis. For each of these patients, each patient diagnosed with refractory anemia with ring sideroblasts was matched for age and sex. At the same time, a cohort of 454 patients with essential thrombocythemia was used to compare outcomes of the two diseases., Results: In patients with refractory anemia with ring sideroblasts and marked thrombocytosis, depending on the Janus Kinase 2 V617F mutational status (positive or negative) or platelet threshold (over or below 600 × 10(9)/L), no difference in survival was noted. However, these patients had shorter overall survival and leukemia-free survival with a lower risk of thrombotic complications than did patients with essential thrombocythemia (P<0.001) but better survival (P<0.001) and a higher risk of thrombosis (P=0.039) than patients with refractory anemia with ring sideroblasts., Conclusions: The clinical course of refractory anemia with ring sideroblasts and marked thrombocytosis is better than that of refractory anemia with ring sideroblasts and worse than that of essential thrombocythemia. The higher risk of thrombotic events in this disorder suggests that anti-platelet therapy might be considered in this subset of patients. From a clinical point of view, it appears to be important to consider refractory anemia with ring sideroblasts and marked thrombocytosis as a distinct entity.

Aim: Thymidine phosphorylase/platelet-derived endothelial cell growth factor (TP/PD-ECGF) is upregulated in several cancers and plays an important role in angiogenesis and invasion of solid tumors. In this study, we investigated the expression of TP/PD-ECGF in gastric carcinoma and its correlation with clinicopathological features and thrombocytosis, and also determined their prognostic significance., Methods: Ninety-eight tissue specimens were resected from patients with gastric carcinoma. The immunohistochemical staining was used for expression of TP/PD-ECGF, platelet counts (PLT) of all patients before surgery were recorded. Patients were divided into high and low TP/PD-ECGF expression groups. Correlations among TP/PD-ECGF expression, PLT and the clinicopathological features of the patients and their prognostic values were studied statistically., Results: Sixty-one cases of high TP/PD-ECGF expression (62%) and 37 cases of low TP/PD-ECGF expression (38%) were detected. There were 21 patients with thrombocytosis (21%). The results show that high TP/PD-ECGF expression was correlated positively with thrombocytosis (P = 0.046, r = 0.20). The 5-year overall survival rate was 46.0% in patients with low TP/PD-ECGF expression, whereas it was only 14.8% in patients with high TP/PD-ECGF expression (P = 0.000). The 5-year survival rate for patients with and without thrombocytosis were 9.5% and 31.2%, respectively, and there was a significant difference between them (P = 0.0001). The multivariate Cox regression analysis showed that high TP/PD-ECGF expression and thrombocytosis would play a role as independent prognostic factors in patients with gastric carcinoma., Conclusions: High TP/PD-ECGF expression and thrombocytosis can be regarded as valuable tools for predicting overall survival in patients with gastric carcinoma., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Hereditary thrombocythemia (HT) has been described as a rare benign disorder caused by mutations in the thrombopoietin (THPO) or the c-Mpl receptor genes. Here we report two families with HT resulting from a THPO c.13+1 G>C mutation in the splice donor of intron 3. In one family there were coexisting distal limb defects, whereas in the other one member developed early-onset multiple myeloma. These observations, together with previously reported patients, suggest that THPO gain of function may dysregulate the hemangioblast and disturb vasculogenesis and hematopoietic development. Overstimulation of the THPO pathway might therefore predispose to clonal hematopoietic disease and to congenital abnormalities.

Background: Thrombocytosis has been associated with malignancies and poor prognostic implications in cancer patients. In the present study the prognostic significance of pretreatment platelet (PLT) level was assessed with regard to recurrence and survival in patients with primary gastric adenocarcinoma., Methods: The authors reviewed the prospective data of 1593 gastric cancer patients who received curative gastrectomy with extended lymphadenectomy. The correlations of PLT level with recurrence and overall survival were evaluated by both univariate and multivariate analyses., Results: Thrombocytosis (≥ 40 × 10(4)/ μL), present in 6.4% of the patients prior to curative surgery, was more frequently associated with advanced T and N classification, larger tumor size, anemia, and leukocytosis (p < 0.05). In patients with pretreatment thrombocytosis compared to those without it, five-year survival rate was worse (56.9% vs. 65.5%; p = 0.043), and recurrence rate was higher mainly due to the frequent hematogenous spread (51.0% vs. 34.5%; p < 0.001). Furthermore, risk of blood-borne metastasis was almost three-fold higher in patients with pretreatment thrombocytosis (Odds ratio 2.83 [95% CI 1.67-4.77], p < 0.001)., Conclusions: Pretreatment thrombocytosis correlated significantly with poor prognosis and can be used as an independent predictor of recurrence by blood-borne metastasis in gastric cancer., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Background: Thrombocytosis has been associated with various conditions, including inflammation, neoplasia, iron deficiency, splenectomy, and drug administration., Objective: The aim of this study was to characterize diseases and conditions associated with thrombocytosis in dogs., Methods: In this retrospective study, dogs with thrombocytosis (platelet count > 600 × 10(3) /μL) and complete medical records during a 1-year period were included, and breed, sex, age, CBC results, alkaline phosphatase and gamma-glutamyltransferase activities in some dogs, administration of glucocorticoids or vincristine, and primary diagnosis were evaluated., Results: Thrombocytosis was found in 240 of 5342 dogs (4.6%), and 165 (3.1%) met inclusion criteria. Thrombocytosis was secondary in all dogs, and underlying diseases and conditions (n,%) were neoplasia (56, 33.9%), inflammation (55, 33.3%), miscellaneous disorders (26, 15.8%), neoplasia plus a second disease (13, 7.9%), endocrine diseases (8, 4.8%), and multiple diseases (7, 4.2%). In dogs with neoplasia, carcinomas (24) and round cell neoplasms (20), especially lymphoma and mast cell tumor, were the most frequent tumors. Inflammatory disorders consisted of immune-mediated disorders (11), neurologic diseases (8), infectious diseases (6), allergic disease (5), orthopedic diseases (4), gastrointestinal diseases (4), and miscellaneous conditions (17). Of the 165 dogs, 73 (44.2%) had received glucocorticoids (55) or vincristine (18) Marked (850-969 × 10(3) platelets/μL) or extreme ( ≥ 970 × 10(3) platelets/μL) thrombocytosis occurred in 24 (14.5%) dogs; 12 (50.0%) had neoplasia. Thromboembolism occurred in 13 (7.9%) dogs., Conclusions: Thrombocytosis in dogs occurred most frequently secondary to neoplastic and inflammatory diseases and was commonly associated with glucocorticoid and vincristine administration. Thromboembolic complications occurred in a small number of patients. Marked or extreme thrombocytosis was more likely to occur with neoplasia than with other conditions., (© 2012 American Society for Veterinary Clinical Pathology.)

Sixty-four patients < 20 years of age, investigated for a suspicion of Philadelphia-negative myeloproliferative disease (MPD), were retrospectively evaluated to characterize the different forms and to examine the treatments used and long-term outcome. JAK2 mutations, endogenous erythroid colony growth, and clonality were investigated in 51 children. Mutations of thrombopoietin, the thrombopoietin receptor (MPL), and the erythropoietin receptor and mutations of other genes involved in the pathogenesis of MPD were investigated in JAK2 wild-type patients. Based on our criteria for childhood MPD, we identified 34 patients with sporadic thrombocythemia (ST), 16 with hereditary thrombocytosis (HT), 11 with sporadic polycythemia (SP), and 3 with hereditary polycythemia (HP). JAK2(V617F) mutations were present in 47.5% of ST and in no HT. The MPL(S505A) mutation was detected in 15/16 HT patients and in no ST (P < .00001). The JAK2(V617F) mutation occurred in 27% of SP patients diagnosed according to the Polycythemia Vera Study Group or World Health Organization 2001 criteria. Children with ST received more cytoreductive drugs than those with HT (P = .0006). After a median follow-up of 124 months, no patient had developed leukemia or myelofibrosis and 5% had thrombosis; the miscarriage rate in thrombocythemic patients was 14%. The low complication rate in our population suggests that children with MPD may be managed by tailored approaches.

Extreme thrombocytosis is a major risk factor for excessive bleeding and for thrombosis, either of which can complicate cardiovascular surgical and interventional procedures. Extreme thrombocytosis can also cause an unusual syndrome, erythromelalgia, that results in a type of chronic microvascular occlusive arterial disease. We present the differential diagnosis of conditions that may lead to extreme thrombocytosis, 3 cases (each of which illustrates a different potential complication), and a review of the pertinent medical literature. Correcting excessive thrombocytosis is typically not difficult, whether electively or acutely, and effective therapy usually controls thrombosis and excessive hemorrhage post-procedurally.

Pseudohypoaldosteronism type 1 (PHA1) is a disease involving a state of renal tubular unresponsiveness to the action of aldosterone and characterized by excessive salt loss in the urine, hyperkalemia, and metabolic acidosis. In kidney, PHA1 may occur primarily by mutations in the subunits of the sodium channel or in the mineralocorticoid receptors, and secondarily by several renal disorders. Miliaria rubra and thrombocytosis are reported in a 6-month-old girl with PHA1. In patients with PHA1, miliaria rubra-like cutaneous eruptions are suggested to occur due to obstruction of eccrine sweat glands through inflammation caused by excessive sodium excretion in sweat during hyponatremic crises. The presence of thrombocytosis in patients with PHA1 has not been previously reported. A hypothesis is proposed suggesting that sympathetic activation which provides vascular tonus during sodium excretion in sweat and salt-depletion crisis may play a role in the development of eruptions and thrombocytosis in patients with PHA1.

Objective: To examine the connection between preoperative thrombocytosis and hematocrit and survival in a group of patients operated for renal cell carcinoma., Methods: Retrospective study with descriptive and statistical analysis of 139 patients with renal cell carcinoma treated surgically over the last 4 years in our Urology clinical unit. 116 (83,45%)were diagnosed at a localized clinical stage, whereas 23 (16,54%) presented as locally advanced or metastatic disease. We collected data about survival and time on surveillance, imaging and histological characteristics of the tumor and analytical parameters. Data were analyzed by the SPSS statistical software., Results: The average platelet count and hematocrit before surgery were 260,930 cells/mm3 and 41.10%, respectively. We found a statistical correlation between platelet count at the time of diagnosis and survival. Patients with platelet counts higher than 350,000 cells/mm3 had a poor survival (OR: 2.94; CI 95% 1.04- 8.27). We also found that patients with high hematocrit at diagnosis presented a lower risk of death (OR: 0.92; CI 95% 0.85- 0.99). The global survival at the end of the study was 88.4%. Multivariate analysis did not show any significant result because of the low number of deaths., Conclusion: The presence of high platelet count or low hematocrit correlate with poor survival in a group of surgically treated renal cell carcinoma patients. Nevertheless more studies with longer surveillance and higher number of patients are needed.

Background: It is not clear why cardiac or renal cachexia in chronic diseases is associated with poor cardiovascular outcomes. Platelet reactivity predisposes to thromboembolic events in the setting of atherosclerotic cardiovascular disease, which is often present in patients with end-stage renal disease (ESRD)., Objectives: We hypothesized that ESRD patients with relative thrombocytosis (platelet count >300 × 10(3)/μL) have a higher mortality rate and that this association may be related to malnutrition-inflammation cachexia syndrome (MICS)., Design: We examined the associations of 3-mo-averaged platelet counts with markers of MICS and 6-y all-cause and cardiovascular mortality (2001-2007) in a cohort of 40,797 patients who were receiving maintenance hemodialysis., Results: The patients comprised 46% women and 34% African Americans, and 46% of the patients had diabetes. The 3-mo-averaged platelet count was 229 ± 78 × 10(3)/μL. In unadjusted and case-mix adjusted models, lower values of albumin, creatinine, protein intake, hemoglobin, and dialysis dose and a higher erythropoietin dose were associated with a higher platelet count. Compared with patients with a platelet count of between 150 and 200 × 10(3)/μL (reference), the all-cause (and cardiovascular) mortality rate with platelet counts between 300 and <350, between 350 and <400, and ≥400 ×10(3)/μL were 6% (and 7%), 17% (and 15%), and 24% (and 25%) higher (P < 0.05), respectively. The associations persisted after control for case-mix adjustment, but adjustment for MICS abolished them., Conclusions: Relative thrombocytosis is associated with a worse MICS profile, a lower dialysis dose, and higher all-cause and cardiovascular disease death risk in hemodialysis patients; and its all-cause and cardiovascular mortality predictability is accounted for by MICS. The role of platelet activation in cachexia-associated mortality warrants additional studies.

This guideline is intended to guide appropriately trained and licensed physicians performing therapy with unsealed radiopharmaceutical sources. Adherence to this guideline should help to maximize the efficacious use of these procedures, maintain safe conditions, and ensure compliance with applicable regulations. The topics dealt with in this guideline include indications for the use of iodine-131, both for the treatment of hyperthyroidism and thyroid carcinoma. In addition, indications for other less common procedures include those for the use of phosphorous-32 in its liquid and colloidal forms, strontium-89, samarium-153, and the use of Y-90 antibodies.

OBJECTIVE •To investigate preoperative platelet level (PLT) as a prognostic factor for pathologic and clinical outcomes following surgery for renal cortical malignancy. PATIENTS AND METHODS • 1422 patients underwent radical or partial nephrectomy at our institution from 1988-2009 for renal cortical lesions. • The cohort with available PLT values was divided into group 1 (PLT ≤ 400 × 10⁹) and (PLT > 400 × 10⁹) based on institutional laboratory upper threshold (400 × 10⁹ cells/liter). RESULTS • 961 patients were divided into groups 1 (n = 870) and 2 (n = 91), with mean age at surgery of 61 and 60 years, 70.6% and 50.6% males (P ≤ 0.0001), 56% undergoing radical nephrectomy in each group, 39.1% vs. 22% undergoing partial nephrectomy (P = 0.001) respectively. • Groups differed significantly inmedian tumour size (5.06 vs. 7.28 cm) (P ≤ 0.001), pathologic T stage (P = 0.002), and metastases (P ≤ 0.0001). No significant difference existed regarding histologic findings at surgery. • With median follow-up of 24 months, PLT > 400 × 10⁹ cells/liter was associated with decreased overall (OS) and disease-specific survival (DSS) using log rank test (P ≤ 0.0001). • On multivariate analysis, controlling for TNM stage, histology, and tumour diameter, PLT > 400 × 10⁹ cells/liter independently predicted decreased OS (HR 1.67, P = 0.007) and DSS (HR 2.39, P = 0.001). As a continuous variable, PLT predicted OS (HR 1.002, P = 0.005) and DSS (HR 1.003, P = 0.004). • With metastatic patients excluded, PLT was significantly associated with OS and DSS, but was not an independent predictor. CONCLUSION • PLT is a clinically significant independent predictor of OS and DSS in continuous and categorical analyses in patients undergoing renal cortical malignancy surgery. PLT may be clinically useful for risk stratifying patients undergoing surgery for renal cancer, especially for prognosis assessment of patients with renal cortical malignancy and micrometastatic disease at surgery., (© 2010 THE AUTHORS. BJU INTERNATIONAL © 2010 BJU INTERNATIONAL.)

Polycythemia vera (PV) and essential thrombocythemia (ET) are two Philadelphia-negative myeloproliferative neoplasms (MPN) associated with an acquired mutation in the JAK2 tyrosine kinase gene. There is a rare incidence of progression to myelofibrosis and myeloid metaplasia in both disorders, which may or may not precede transformation to acute myeloid leukemia, but thrombosis is the main cause of morbidity and mortality. The pathophysiology of thrombosis in patients with MPN is complex. Traditionally, abnormalities of platelet number and function have been claimed as the main players, but increased dynamic interactions between platelets, leukocytes, and the endothelium do probably represent a fundamental interplay in generating a thrombophilic state. In addition, endothelial dysfunction, a well-known risk factor for vascular disease, may play a role in the thrombotic risk of patients with PV and ET. The identification of plasma markers translating the hemostatic imbalance in patients with PV and ET would be extremely helpful in order to define the subgroup of patients with a significant clinical risk of thrombosis.

Neonatal alloimmune neutropenia (NIN) results from the destruction of foetal neutrophils by maternal immunoglobulin G-class neutrophil-reactive antibodies crossing the foeto-placental barrier. We report two cases of neonatal patients presenting with unspecific symptoms and persisting neutropenia accompanied by thrombocytosis. Both were subsequently diagnosed with NIN. These two cases of persisting neutropenia highlight the diversity of symptoms and the diagnostic challenges remaining in NIN. Furthermore, the cases remind us that neutropenia in neonates may be rooted in several different pathophysiological mechanisms.

Thrombohaemorrhagic syndrome is a clinical syndrome manifesting with concurrent bleeding and thrombosis. It is associated with a range of pathological states, typically with myeloproliferative diseases, paraproteinaemia, liver disease as well as disseminated intravascular coagulation and similar syndromes (so called DIC-like syndrome). Thrombohaemorrhagic syndrome might be a symptom of chronic myeloproliferations, particularly if these are associated with thrombocythemia. It is most frequently linked to essential thrombocythemia. However, in this disease, it seems that the clinical symptoms of bleeding and thrombosis might not be directly determined by the number of platelets, as it would suggest itself, but that this can be consequent to other changes. These may include predisposition to thrombophilia, cardiovascular risk, leukocytosis etc. as well as, for example, platelet dysfunction. The present study focuses on platelet dysfunction in conjunction with clinical symptoms of bleeding and thrombosis.

According to the World Health Organization (WHO) classification of tumors of hematopoietic and lymphoid tissues, myelodysplastic/myeloproliferative neoplasms are clonal myeloid neoplasms that have some clinical, laboratory, or morphologic findings that support a diagnosis of myelodysplastic syndrome, and other findings that are more consistent with myeloproliferative neoplasms. These disorders include chronic myelomonocytic leukemia, atypical chronic myeloid leukemia (BCR-ABL1 negative), juvenile myelomonocytic leukemia, and myelodysplastic/myeloproliferative neoplasms, unclassifiable. The best characterized of these latter unclassifiable conditions is the provisional entity defined as refractory anemia with ring sideroblasts associated with marked thrombocytosis. This article focuses on myelodysplastic/myeloproliferative neoplasms of adulthood, with particular emphasis on chronic myelomonocytic leukemia and refractory anemia with ring sideroblasts associated with marked thrombocytosis. Recent studies have partly clarified the molecular basis of these disorders, laying the groundwork for the development of molecular diagnostic and prognostic tools. It is hoped that these advances will soon translate into improved therapeutic approaches.

Background and Aims: In lung cancer, many factors have prognostic significance, including thrombocytosis, which is frequently observed. Associations between vascular events, which are the outcomes of paraneoplastic symptoms, and mortality and morbidity has been evaluated in many studies. The aim of the present study was to evaluate the relationship between thrombocytosis and vascular events., Materials and Methods: In total, 281 patients, who were histopathologically diagnosed with lung cancer between March 2007 and August 2009, were evaluated retrospectively. Data analysis was performed using the Statistical Package for the Social Sciences (SPSS) software (ver. 11.5 for Windows). Analysis of the distribution of constant variance for normality was assessed using the Shapiro-Wilk test. Nominal variables were evaluated using Pearson's chi-squared or Fisher's exact chi-squared tests. Significant correlations between continuous variables were investigated using Spearman's correlation test., Results: Of the 281 patients, 234 (83.3%) were males and 47 (16.7%) were females, with a median age of 60.6 (31-83 years). Histopathologically, 40 (14.2%) were diagnosed with small-cell lung cancer and 241 (85.8%) with non-small cell lung cancer. In total, 17 (6.04%) vascular events were identified: 11 (64.7%) deep vein thromboses, three (17.6%) pulmonary thromboembolisms, one (5.9%) cerebral arterial thrombosis, and one (5.9%) vena cava superior thrombosis. Thrombocytosis was not determined during thrombosis, but during subsequent visits., Conclusions: Thrombocytosis is frequently observed in patients with lung cancer. Further prospective studies are required to evaluate the need for prophylactic anticoagulants in these patients. The association between vascular events and survival, the next step of the present study, will be evaluated prospectively.

The P2Y12 receptor plays a crucial role in the regulation of platelet activation by several agonists, which is irreversibly antagonized by the active metabolite of clopidogrel, a widely used anti-thrombotic drug. In this study, we investigated whether reduction of platelet reactivity leads to reduced inflammatory responses using a rat model of erosive arthritis. We evaluated the effect of clopidogrel on inflammation in Lewis rats in a peptidoglycan polysaccharide (PG-PS)-induced arthritis model with four groups of rats: 1) untreated, 2) clopidogrel-treated, 3) PG-PS-induced, and 4) PG-PS-induced and clopidogrel-treated. There were significant differences between the PG-PS+clopidogrel group when compared to the PG-PS group including: increased joint diameter and clinical manifestations of inflammation, elevated plasma levels of pro-inflammatory cytokines (IL-1 beta, interferon (IFN) gamma, and IL-6), an elevated neutrophil blood count and an increased circulating platelet count. Plasma levels of IL-10 were significantly lower in the PG-PS+clopidogrel group compared to the PG-PS group. Plasma levels of platelet factor 4 (PF4) were elevated in both the PG-PS and the PG-PS+clopidogrel groups, however PF4 levels showed no difference upon clopidogrel treatment, suggesting that the pro- inflammatory effect of clopidogrel may be due to its action on cells other than platelets. Histology indicated an increase in leukocyte infiltration at the inflammatory area of the joint, increased pannus formation, blood vessel proliferation, subsynovial fibrosis and cartilage erosion upon treatment with clopidogrel in PG-PS-induced arthritis animals. In summary, animals treated with clopidogrel showed a pro-inflammatory effect in the PG-PS-induced arthritis animal model, which might not be mediated by platelets. Elucidation of the mechanism of clopidogrel-induced cell responses is important to understand the role of the P2Y12 receptor in inflammation.

Hydroxyurea (HU) is frequently given as treatment for myelofibrosis (MF), but data on its efficacy and tolerability are scarce. The results of HU therapy were evaluated in 40 patients with hyperproliferative manifestations of primary (n = 32), post-polycythemia vera (n = 6), or post-essential thrombocythemia (n = 2) myelofibrosis. Median interval between diagnosis and HU start was 6.2 months (range 0-141.7). Reasons for treatment were constitutional symptoms (55%), symptomatic splenomegaly (45%), thrombocytosis (40%), leukocytosis (28%), pruritus (10%), and bone pain (8%). The starting dose was 500 mg/day, subsequently adjusted to the individual efficacy and tolerability. Response was bone pain 100%, constitutional symptoms 82%, pruritus 50%, splenomegaly 40%, and anemia 12.5%. According to the International Working Group for Myelofibrosis Research and Treatment criteria, clinical improvement was achieved in 16 patients (40%). Median duration of response was 13.2 months (range 3-126.2). Worsening of the anemia or appearance of pancytopenia were observed in 18 patients, requiring administration of erythropoietin-stimulating agents (n = 17) and/or danazol (n = 9). Oral or leg ulcers appeared in five patients and one had gastrointestinal symptoms. HU is an effective and generally well-tolerated therapy for the hyperproliferative manifestations of MF. The accentuation of the anemia often induced by HU is usually manageable with concomitant treatment.

We report on a case of late stent thrombosis after drug-eluting stent placement in a patient with essential thrombocytosis. A 51-year-old male patient with a three-month history of paclitaxel-eluting stent placement to the left anterior descending artery presented with a complaint of severe retrosternal chest pain. A high platelet count (1,063,000/mm3) was detected two months prior to presentation, which was interpreted as essential thrombocytosis. He was on standard dual antiplatelet therapy (aspirin and clopidogrel). The electrocardiogram showed ST-segment elevation in leads V1-V6. Emergent coronary angiography revealed thrombotic total occlusion at the location of the paclitaxel-eluting stent. Balloon angioplasty was performed yielding a satisfactory result and TIMI 3 flow. Following the procedure, there was no chest pain. His platelet count was 388,000/mm3. He was discharged on medical therapy following an uneventful hospital course. Patients with essential thrombocytosis may not be eligible for drug-eluting stent placement.

There is a lack of published information about intraoperative and postoperative course of cardiac surgery in patients with essential thrombocytosis using cardiopulmonary bypass. Both risks of intraoperative thrombosis of extracorporeal conduits or uncontrolled postoperative bleeding are present, but its incidence and treatment are not well known. Here, we present a rare case of a patient with essential thrombocytosis, moderate mitral regurgitation and severe aortic stenosis who had a transapical aortic valve implantation with short-term severe periprosthetic regurgitation, who needed a mitroaortic replacement on cardiopulmonary bypass with no complications.

POEMS (polyneuropathy, organomegaly, endocrinopathy, M-band, and skin changes) syndrome is characterized by chronic progressive polyneuropathy and plasma-cell dyscrasia. A major diagnostic criterion of POEMS is elevation of circulating vascular endothelial growth factor (VEGF), which is believed to play a pathogenic role in this disease. We report a case of POEMS that presented as relapsing acute inflammatory demyelinating polyneuropathy, in which complete remission after intravenous immunoglobulin (IVIg) treatment was unexpectedly observed. At clinical nadir, the VEGF level was 30-fold higher, and the soluble form of VEGF receptor 2 (sVEGFR2), which acts as a decoy for VEGF, was 2.7-fold lower than normal. These changes combined might contribute to the pathogenesis of POEMS, inducing vascular permeability and tissue edema. At 9-month follow-up, during clinical remission, VEGF and sVEGFR2 were near normal values. sVEGFR2 reduction is a new finding in POEMS. IVIg treatment may benefit POEMS patients with acute neuropathy by downgrading VEGF release induced by inflammatory cytokines.

Pseudohyperkalaemia in conditions with increased platelet counts is caused by an in vitro rise of the serum potassium concentration during whole blood coagulation and the lysis of the platelets and other cellular components, in the presence of normal renal function and normal plasma potassium levels. The association between pseudohyperkalaemia and aetiology of thrombocytosis was studied in a 6-year retrospective audit on 90 patients with thrombocytosis referred to the Haematology Department in Ulster Hospital Dundonald, a large district general hospital. Over two-thirds of this study population had myeloproliferative disorders, and the most common diagnosis was primary thrombocythaemia (41%, n = 37). Reactive thrombocytosis was observed in approximately one-third of the cases (32%, n = 29). Pseudohyperkalaemia with apparent potassium level above the upper limit of the normal range (reference range K 3.5-5.1 mmol/l) was observed in the majority of patients with thrombocytosis from any aetiology (60%, n = 54). The likelihood of finding pseudohyperkalaemia was highest among patients with primary thrombocythaemia (75.7%, n = 28/37) and polythaemia rubra vera (75%, n = 12/16), followed by myelofibrosis (50%, 4/8) and reactive thrombocytosis (34.5%, n = 10/29). A highly significant positive correlation was observed between the platelet counts and the serum potassium level (Spearman's correlation coefficient, R = 0.998, P = 0.01). Awareness of pseudohyperkalemia in disease conditions with increased platelet counts will lead to the withholding of potentially harmful treatment.

Background: Platelets are inflammatory cells with an important role in antimicrobial host defenses. We speculate that an abnormal platelet count may be a marker of severity in patients with community-acquired pneumonia (CAP). The objectives of this study were to evaluate if abnormal platelet count in hospitalized patients with CAP was associated with 30-day mortality and to compare platelet count and leukocyte count as predictors of 30-day mortality., Methods: We performed a retrospective cohort study of 500 consecutive patients hospitalized with CAP at the Veterans Hospital of Louisville, Kentucky, between June 2001 and March 2006 to investigate the association of platelet count and leukocyte count with 30-day mortality. Predictor variables were platelet count and leukocyte count. Abnormal platelet count was < 100,000/L (thrombocytopenia) and > 400,000/L (thrombocytosis). The outcome variable was 30-day mortality. To control for potential confounding, a propensity score that incorporated 33 variables was used., Results: Platelet count was strongly associated (P = .0009) with 30-day mortality, whereas no association was observed for leukocyte count (P = .5114). High platelet counts resulted in a significantly increased risk of mortality., Conclusions: Thrombocytopenia and thrombocytosis are associated with mortality in patients hospitalized with CAP. When evaluating an initial CBC test in patients with CAP, an abnormal platelet count is a better predictor of outcome than an abnormal leukocyte count.

Budd-Chiari syndrome secondary to essential thrombocytosis has been described in a few reports in the English literature. Associated portal vein thrombosis occurs very rarely. Herein, we report a case presented with ascites and finally diagnosed with hepatic and portal vein thrombosis, and essential thrombocytosis. We discussed the therapeutic approaches in the light of pertinent literature.

Background: High circulating platelet counts have been associated with poor prognosis in a variety of solid tumours such as breast, renal and lung cancer. We investigated the significance of a high pre-operative platelet count on overall survival in patients with stages I-IV colorectal cancer., Patients and Methods: 630 Consecutive patients who colorectal cancer resection between 2004 and 2007 with a full blood count taken 14 days prior to the surgery were assessed. Male:female 7:5, median (range) age 73 (40-99 years). Thrombocytosis was defined as platelet count of ≥450 × 10(9)/L. The relationship between platelet count, pathological features and overall survival was assessed., Results: : Mantel-Cox regression showed that platelet count does not predict survival on multivariate analysis (p = 0.067). Thrombocytosis was present in 51/627 (8.1%) of cases. There was no statistically significant difference in mean survival (p = 0.067) observed in patients with platelet count <450 × 10(9)/L (n = 576; 95%CI: 1550.5-1405.4 SE 37.0) versus ≥450 × 10(9)/L (n = 51, CI: 1261.6-955.0, SE 78.2). There was also no correlation between Dukes stage and thrombocytosis., Conclusion(s): In our study, pre-operative thrombocytosis is not a prognostic indicator of survival in colorectal cancer patients regardless of pathological stage., (Copyright © 2010 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.)

Unlabelled: Background The MPL(Ser505Asn) mutation has been reported to be a cause of hereditary thrombocythemia. Recently, we detected this mutation in a large proportion of children with familial thrombocythemia, suggesting that in Italy the incidence of MPL(Ser505Asn) mutation could be underestimated., Design and Methods: We extended the search for this mutation to all patients with essential thrombocythemia who had a positive family history for thrombocytosis or essential thrombocythemia. We identified eight Italian families positive for the MPL(Ser505Asn) mutation. Clinical and hematologic data were available for members of seven families, including 21 patients with a proven mutation and 20 relatives with thrombocytosis., Results: Fifteen major thrombotic episodes, nine of which were fatal, were recorded among 41 patients. The thrombotic manifestation was stroke in four cases, myocardial infarction in seven cases, fetal loss in two cases, deep vein thrombosis of the leg in one case and Budd Chiari syndrome in one case. Almost all patients over 20 years old had splenomegaly and bone marrow fibrosis, while these were rarely observed in patients under 20 years old, suggesting that these manifestations are associated with aging. Finally, the life expectancy of family members with thrombocytosis was significantly shorter than that of members without thrombocytosis (P=0.003). Conclusions Patients with familial thrombocytosis caused by a MPL(Ser505Asn) mutation have a high risk of thrombosis and, with aging, develop splenomegaly and bone marrow fibrosis, significantly affecting their life expectancy.

Purpose: We assessed the association of preoperative thrombocytosis with prognostic factors in malign ovarian tumor., Methods: Over a five-year period, cases treated for ovarian cancer were randomly assigned. The data were collected from gynecological oncology, radiation oncology, medical oncology and pathology departments. Statistical analyses were carried out by using the statistical packages for SPSS 12.0 for Windows (Chicago, IL, USA). Survival was analyzed by the method of Kaplan and Meier, using log-rank (Mantel-Cox) analysis., Results: 51 cases with ovarian cancer were evaluated. Cases with thrombocytosis were found to have greater CA-125 levels, more advanced stage disease, more ascites and shorter periods of survival., Conclusion: Thrombocytosis is a poor prognostic factor in ovarian cancer. As reported previously, it is associated with aggressive tumor biology. Thus, preoperative thrombocytosis can be a used as a marker of poor outcomes.

Subdural hygroma is a frequent delayed complication of head trauma. It is a rare form of bleeding. Most hygromas are clinically silent and a few cases have shown slow deterioration in the chronic stage. We report a case of a 72-years-old male presented with a mild headache, consciousness disturbance and gait ataxia after head injury. Cranial computed tomography revealed subdural hygroma. The hygroma was associated to thrombocythemia. The patient was treated with chemotherapy with hydroxyurea with rapid resolution. In conclusion subdural hygroma may resolve spontaneously. Surgery might be deferred except in emergency conditions or in patients with normal neurological findings. Subdural hygroma in patient with thrombocythemia is first time presenting.

Perivascular epithelioid cell tumors of the lung are rare, benign neoplasms, usually presenting as a solitary pulmonary nodule on chest roentgenograms. Most lesions are solitary and asymptomatic, and are located within the peripheral lung. This is a case report of a 44-year-old woman who presented with thrombocytosis and solitary pulmonary nodule of the lung, which was removed by a thoracotomy.

Portal vein thrombosis is a major complication of splenectomy. Its frequency is underestimated because of asymptomatic cases. Mesenteric occlusion with intestinal infarcts is the first cause of mortality. Secondarily, in the absence of repermeabilisation, a portal hypertension can occur. We present in this study 4 cases of portal vein thrombosis in childhood. Portal vein thrombosis is frequent (8% of splenectomies) and may be asymptomatic. Doppler postoperative surveillance is justified. Thrombocytosis seems to be a determinant factor. Early diagnosis and treatment may reduce lethal outcome.