Search

The Merkel cell carcinoma is a rare, serious, neuroendocrine, malignant skin cancer with lymph node involvement in half of patients and disseminated metastases in 20% of cases at the time of pathological diagnosis. Its treatment is not fully established, though the sentinel lymph node has been considered essential and may bring benefits to the therapeutic armamentarium of patients.

Merkel cell carcinoma is a rare aggressive neuroendocrine carcinoma of the skin predominantly affecting elderly Caucasians. It has a high rate of local recurrence and regional lymph node metastases. It is associated with a poor prognosis. Complete spontaneous regression of Merkel cell carcinoma has been reported but is a poorly understood phenomenon. Here we present a case of complete spontaneous regression of metastatic Merkel cell carcinoma demonstrating a markedly different pattern of events from those previously published.

Background: Merkel cell carcinoma (MCC) is a rare cutaneous malignancy with high mortality. Positron emission tomography (PET) using (18)F-fluorodeoxyglucose (FDG) has been shown to be valuable in the management of many types of cancer, and the purpose of this work was to determine its utility for patients with MCC., Objective: We sought to evaluate the impact of (18)F-FDG PET with simultaneous computed tomography (PET-CT) on the staging and management of patients with MCC., Methods: We reviewed the medical records of 18 patients with MCC who underwent 21 PET-CT scans at our institution from 2006 to 2008. The impact of PET-CT on staging and management plans were evaluated., Results: There were 12 men and 6 women with median age of 79 years (range, 54 to 85 years). All proven sites of MCC greater than 5 mm were positive on PET-CT with average maximum standardized uptake values (SUV max) of 4 in primary lesions, 5.6 in nodal disease and 11.5 in distant metastases. PET-CT contributed to altered staging in 7 patients (33%) and a change in management in 9 patients (43%). Two patients were found to have a second primary malignancy, but this did not alter management., Limitations: This was a retrospective review. Most patients had stage II or III disease, suggesting some potential referral bias., Conclusions: (18)F-FDG PET-CT had a high impact in the management of MCC patients in our series and this investigation merits further assessment.

Background: Merkel cell carcinoma (MCC) is a relatively infrequent, rapidly progressive and often fatal cutaneous malignancy exhibiting neuroendocrine differentiation. It has a penchant for local recurrence and distant metastasis to various sites, including regional lymph nodes, distant skin, lung, liver, testis and other rare organs, such as the pancreas. There are only 4 cases of MCC metastatic to the pancreas reported in the English-language literature, and they were all diagnosed by histology from pancreatic resection., Case: A 79-year-old woman with a large pancreatic tail mass underwent endoscopic ultrasound guided fine needle aspiration (EUS-FNA). She had a history of MCC of the upper extremity with wide local excision 15 months earlier. Metastatic MCC was diagnosed based on the cytomorphology, characteristic immunohistochemical staining pattern, clinical history and comparison of the morphology with that of the primary tumor., Conclusion: The cytomorphology and immunohistochemical profile of this neoplasm mimicked a pancreatic endocrine tumor. We discuss the diagnostic pitfalls and differential diagnoses of the metastatic pancreatic MCC, highlighting the importance of thorough clinical history, attention to cytologic detail and corroborating immunohirtochemistry in arriving at the correct diagns. This is the first case ofa metastatic pancreatic MCC diagnosed by EUS-FNA cytology.

Merkel cell carcinoma is a rare, aggressive, cutaneous malignancy of the elderly with a generally poor prognosis. Like all skin cancers, its incidence is rising. A few reports of spontaneous regression have been published. The case of a 67-year-old female patient who presented with a cheek Merkel cell carcinoma is described. Following biopsy it underwent complete regression with no evidence of residual tumour in the excision specimen taken seven weeks later. The current knowledge of Merkel cell carcinoma and the other cases of spontaneous regression described in the literature are reviewed.

Background: We analyzed the variability and accuracy of sentinel lymph node (SLN) identification by lymphoscintigraphy performed preoperatively and repeated on the day of operation in patients with melanoma or Merkel cell cancer., Methods: Twenty-five prospectively studied patients had lymphoscintigraphy prior to and on the day of operation. Discordance between lymphoscintograms was defined as change in location of SLN or failure to identify a SLN by one of the studies., Results: In 22 of 24 assessable cases (92%), SLNs were excised. Preoperative lymphoscintigraphy was correct in 19 of 22 (86%) cases. Day of operation lymphoscintigraphy was correct in 20 of 22 (91%) cases. SLN location was as classically described in 24 of 25 (96%) cases. Discordance between lymphoscintigraphy studies was 32% (8/25 patients). Half with discordant migration (8%) yielded metastases in basins not identified by day of operation lymphoscintigraphy but demonstrated by preoperative lymphoscintigraphy., Conclusions: Head and neck lymphatic drainage patterns not only vary between patients but also can vary with time for a single patient.

Aim: The purpose of this study was to determine the predictive value of lymphatic mapping with selective lymphadenectomy in patients with Merkel's cell carcinoma., Methods: Eight patients with biopsy proven Merkel's cell carcinoma underwent sentinel node biopsy. Lymphoscintigraphy was performed the day before surgery following intradermal injection of 74-111MBq of 99mTc-nanocolloid divided into four doses around the biopsy scar. Dynamic and static images were obtained., Results: At least one sentinel node was visualized in all patients. The sentinel node was intra-operatively identified with the aid of a hand-held gamma probe in all cases and patent blue dye in six out of eight cases. During surgery, all sentinel nodes were successfully harvested. Metastatic cell deposits were subsequently identified in three patients (37.5%) and they underwent regional lymphadenectomy. No additional involved lymph nodes were identified. No recurrence has been reported in a median follow-up of 4.6 years (range: 8 months-10 years)., Conclusions: In conclusion, sentinel node biopsy in patients with Merkel's cell carcinoma appears to be a reliable staging technique.

Merkel cell carcinoma is a rare malignant primary tumor of the skin, which develop typically in the elderly in the sun exposed areas of the skin, most commonly in the head and neck region. This tumor is very aggressive with a high rate of regional and distant metastases, marked propensity for local et regional recurrence, and very poor survival. Skin lesions are typically red or purple and present as a solitary dome-shaped nodule or indurated plaque. The recognition of such tumor in not difficult, but in same cases, when the tumor infiltrate deeper organs and structures it may cause some problems. We describe a case of 86 years old women who was operated in our department with an initial diagnosis of parotid tumor infiltrating the skin of the preauricular region and the facial nerve. The histopatological and immunohistochemical examination of the tumor showed that it was Merkel cell carcinoma, which in fact developed in the skin and infiltrated parotid gland and facial nerve. After operation patient received 2 courses of palliative radiation. Until now during a 4,5 years follow up there was no recurrence of the tumor and the patient is well.

The Authors report two cases of Merkel cell carcinoma and describe their diagnostic and therapeutic difficulties in the management of these tumours. The main therapeutic problem consists in establishing the size of the excision margins in relation to the neoplastic aggressiveness. The first case was characterised by major lymphophilia and by a tendency to relapse. Radical excision was achieved by low invasive surgery using a radioguided technique to search for microscopic disease. The radioguided technique takes the place of the intra-operative anatomo-pathological examination. After adjuvant ra- diotherapy and chemotherapy the patienthas remained in remission for three years. The second case is characterized by a rapid haematic diffusion with metastasis and exitus after one year. Radiotherapy and chemotherapy were ineffective. In this case surgery was limited to a bioptic approach since extirpative surgery would have been inappropriate. Our experience shows the wide biological variability of Merkel cell carcinoma and the importance of eclectic treatment to avoid ineffective extirpative surgery.

Merkel cell carcinoma is a rare form of skin cancer of likely neuroendocrine origin wich affects mainly white population in sun-exposed areas. It is an aggressive tumor and survival is dependent on stage at the time of diagnosis. The staging evaluation include CT imaging and recently PET scan. Surgical excision with or without lymph node dissection, followed by postoperative radiotherapy in stage II disease, is the standard treatment of non metastatic disease. The role of adjuvant chemotherapy is still controversial. In patients with metastatic disease, chemotherapy regimens active in small cell lung cancer are generally used. The combination of cyclophosphamide, doxorubicin and vincristine (CAV) has an overall response rate of 75%, whereas the response rate of etoposide in combination with cisplatin or carboplatin is 60%. Experience with other therapeutic agents, such as tumor necrosis factor, interferon and octreotide is scanty. Recently, encouraging preliminary results with targeted agents have been reported. Our experience in 14 patients, four of whom treated with chemotherapy for advanced disease, is in agreement with literature

Merkel cell carcinoma (MCC) is a rare and highly malignant skin cancer with neuroendocrine differentiation. We studied the potential value of 18FDG PET in the management of MCC. Eleven patients with MCC were examined by 18FDG PET and PET-CT for staging purpose (n=4) or for detection of recurrence (n=7). Qualitative and quantitative interpretation of PET studies was performed routinely. 18FDG PET observations were compared to clinical and radiological findings. In 6 patients, PET findings were also compared to histology. In 7 patients, the 18FDG tumor uptake was compared to the MCC proliferative activity expressed by the Ki-67 index. 18FDG PET was contributive in 10/11 MCC patients. In 7 patients, 18FDG PET detected focal lesions or a disseminated stage of the disease including dermal, nodal and visceral metastases. In 3 patients, a normal 18FDG PET confirmed complete remission of disease. Most MCC patients exhibited highly 18FDG-avid sites suggestive of increased glucose metabolism. This imaging pattern was related to a high proliferative activity (Ki-67 index >50%). In 1 patient with a weakly proliferative nodal MCC (Ki-67<10%), a false negative result was yielded by metabolic imaging. In 4/11 patients, 18FDG PET revealed an unsuspected second neoplasm in addition to MCC. It is concluded that whole-body 18FDG PET may be useful in the management of MCC patients. However, a normal 18FDG PET aspect cannot rule out MCC with low proliferative activity.

Purpose: 2-Deoxy-2-[F-18]fluoro-D-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) is becoming widely available as a powerful imaging modality, combining the ability to detect active metabolic processes and their morphologic features in a single study. The role of FDG-PET/CT is proven in lymphoma, melanoma, colorectal carcinoma, and other cancers. However, there are rare malignancies such as Merkel cell carcinoma that can potentially be evaluated with PET/CT. We were therefore prompted to review our experience with FDG-PET/CT in the management of patients with Merkel cell carcinoma., Procedures: This is a retrospective case series of six patients with Merkel cell carcinoma, 58-81 years old (average 69 +/- 8.3), who had whole-body PET/CT at our institution from January 1st, 2003 to August 31st, 2005. Two patients were women and four were men. Reinterpretation of the imaging studies for accuracy and data analysis from medical records were performed., Results: Twelve examinations were acquired for the six patients (one patient had six PET/CT, one patient had two PET/CT, and four patients had one PET/CT). The injected FDG doses ranged 381.1-669.7 MBq (average 573.5 +/- 70.3). Four patients had the PET/CT as part of initial staging, and two patients had the exam for restaging (after surgery and XRT). A total of six Merkel lesions (pancreas, adrenal, lip, submandibular lymph nodes, cervical lymph nodes, and parapharyngeal soft tissue) were identified in three patients and confirmed on histopathological examination. The FDG uptake in these areas was intense, with maximum standardized uptake value (SUVmax) values of 5-14 (average 10.4 +/- 3.8). In one patient, the PET/CT scan identified abnormal focal distal sigmoid uptake that was biopsied and diagnosed as adenocarcinoma. Two patients had negative scans and had no clinical evidence of disease on follow-up office visits (up to one year after PET/CT)., Conclusions: This case series suggests that FDG-PET/CT may have a promising role in the management of patients with Merkel cell carcinoma.

Objective: To determine the diagnostic accuracy and usefulness of sentinel lymph node biopsy (SLNB) and computed tomographic scans in the initial evaluation and treatment of patients with Merkel cell carcinoma (MCC)., Design: Single-institution case series and literature-based case-level meta-analysis., Setting: Academic cutaneous oncology clinic.Patients Sixty-one adults with biopsy-proven MCC (30 who had undergone SLNB) plus 92 cases from the literature of patients who had undergone SLNB., Main Outcome Measures: Relapse-free survival., Results: In 122 patients with no nodal disease found by physical examination, SLNB findings revealed nodal involvement in 39 cases (32%). At 3 years, the recurrence rate for those with a positive SLNB was 3 times (60%) higher than for those with a negative SLNB (20%; P = .03). Patients with a positive SLNB who received adjuvant nodal therapy had a relapse-free survival rate of 51% at 3 years (n = 26) compared with 0% for patients who did not receive nodal therapy (n = 3; P < .01). In contrast, among patients with a negative SLNB there was no significant difference in 3-year relapse-free survival rates for those who did (90%; n = 24) or did not (70%; n = 19; P = .26) receive adjuvant nodal therapy. Using SLNB plus clinical follow-up as a gold standard, computed tomographic scans had low sensitivity (20%) for detecting MCC that had spread to the lymph node basin and low specificity for distant disease (only 4 of 21 "positive" scans were confirmed during 6 months of follow-up)., Conclusions: Sentinel lymph node biopsy detects MCC spread in one third of patients whose tumors would have otherwise been clinically and radiologically understaged and who may not have received treatment to the involved node bed. There was a significant benefit of adjuvant nodal therapy, but only when the SLNB was positive. Thus, SLNB is important for both prognosis and therapy and should be performed routinely for patients with MCC. In contrast, computed tomographic scans have poor sensitivity in detecting nodal disease as well as poor specificity in detecting distant disease.

Merkel cell carcinoma (MCC) is an infrequent neuroendocrine tumor of the skin with a high potential for local recurrence, lymphatic dissemination and distant dissemination. We present a case of MCC in a male patient with chronic lymphocytic leukemia (CLL). The immunosuppression induced by the leukemia or by the chemotherapy could play a pathogenic role in the association of these diseases. Positron emission tomography (PET) was a useful staging technique in this patient, and made the differential diagnosis of the lymph node involvement from MMC and CLL possible.

Purpose: Merkel cell carcinoma (MCC) is the most aggressive of the cutaneous malignancies, showing a propensity to spread to regional lymph nodes (LNs). The aim of this prospective study was to examine the feasibility and clinical impact of sentinel lymph node biopsy (SLNB) in this cutaneous malignancy., Methods: The study population comprised 23 patients with stage I MCC (median age 70 years, range 50-85 years). Lymphoscintigraphic mapping with( 99 m)Tc-nanocolloid was performed in all patients. Sentinel lymph nodes (SLNs) were identified, excised and analysed in serial sections by conventional histopathology and cytokeratin-20 immunohistochemistry., Results: Metastatic disease was determined in the SLNs of 11 patients (47.8%). Elective lymph node dissection (ELND) was performed in eight of these 11 patients, four of whom had additional positive LNs. During follow-up (median 36.1 months, range 3-79 months), seven of the 23 patients (30%) relapsed: four had a local recurrence and three, in-transit metastases. Recurrence developed in two SLN-negative patients with local LN metastases and in one SLN-positive patient with distant metastases. This patient died, representing the only tumour-related death in our sample. Median survival was 49.1 and 35.5 months for SLN-negative and SLN-positive patients, respectively. This difference was not statistically significant (p=0.3452)., Conclusion: SLNB allows for exact nodal staging in patients with MCC. Whether additional ELND is of further benefit remains unclear.

Background: Merkel cell carcinoma (MCC) is a rare and aggressive skin tumour with a highly malignant nature whose appropriate treatment is still debated. The Authors report a case of cutaneous metastasis from neuroendocrine carcinoma and analyse new diagnostic and therapeutic options of neoplasms that occurs in sun-exposed areas., Methods: The authors present the clinical, immunocytochemical characteristic of primary and secondary skin localization of a neuroendocrine tumor that affected a woman., Results: Histological and immunocytochemical analysis demonstrated that the secondary cutaneous localization appeared to be compared to the primary tumour., Conclusions: The case confirm the high incidence of regional metastasis; a wide surgical excision of tumor and regional lymphadenectomy is therefore recommended for primary treatment of MCC; the radiation treatment minimized the local recidives with long time survival.

Purpose: To assess the feasibility of the Sentinel lymph node biopsy (SLNB) technique in cutaneous non-melanoma malignancies., Materials and Methods: Nine patients were retrospectively evaluated performing a scintigraphy with 99mTc-nanocolloid. On the day of the surgery, an initial dynamic study and static images were obtained. The first drainage station visualized was considered the sentinel node (SLN). The SLN position was marked on the skin and after a correct localization in the surgical field with a gamma probe the SLN was obtained. Patients of this study have been followed up for 8 to 48 months., Results: Lymphoscintigraphy detected the sentinel node in 88,8 % of our studies (the SLN was not observed in a patient with a Merkel's tumour on the back). The SLN was identified intraoperatively in those patients with positive imaging. Those cases without scintigraphic demonstrated migration were also not found intraoperatively. Histopathological analysis of the SLN showed non metastatic disease and none patient developed metastases or local recurrence in the monitoring period., Conclusions: Sentinel node biopsy can be applied to certain cutaneous non-melanoma malignancies. In patients with unclear drainage and to avoid unnecessary lymphadenectomy, the technique offers clear advantages. In our study the SLN analysis was related to the clinical progress. A large number of patients should be examined to truly assess the benefit of this technique in this kind of malignancies and to determinate when the technique must be performed.

Background: Merkel cell carcinoma (MCC) is a rare skin neuroendocrine carcinoma frequently occurring in the head and neck area. It is known for being a locally aggressive disease with a high incidence of regional and distant metastases. Accurate initial staging and close surveillance are critical in the management of the disease., Methods and Results: Two cases of MCC are reported in which fluorine-18-fluorodeoxyglucose positron emission tomography (FDG PET) imaging has been beneficial in directing management and predicting clinical course. Pretreatment FDG PET scans detected metastatic disease in subcentimeter lymph nodes that were not appreciated in initial computed tomography images. Posttreatment FDG PET scans predicted response to therapy with the level of FDG uptake correlating in both areas of complete response to treatment and areas of residual diseases. Finally, FDG PET imaging also detected the progression of the disease after initial treatment., Conclusion: FDG PET imaging is a very sensitive modality in staging, assessment of treatment response, and surveillance of MCC. Because of the rarity of MCC, multicenter study is warranted to accumulate enough cases to determine the sensitivity and specificity of FDG PET in staging and surveillance of MCC, and the impact on the management and treatment outcome.

The "Merkel cell carcinoma" is a rare tumor usually occuring in the sun-exposed skin. Its poor prognosis is explained by a high rate of metastasis (one third of the patients at the initial presentation) and a high post-operative recurrence rate. Descriptions of the imaging features of this type of tumor are rare. We present two cases of Merkel cell carcinoma localized to the head region. In the first patient, the lesion involved the soft tissues of the scalp with secondary invasion of the skull and meninges. The second patient had a metastasis to the parietal lobe.

A 63-year-old man was diagnosed with metastatic MCC. Preliminary staging PET scan with 18F-FDG was not done at the time of diagnosis. After completion of chemo- and radiotherapy, the patient underwent a CT scan of the area from the maxilla to the ischium; no evidence of disease was noted. Clinically, the patient was considered to be in remission. The CT scan was followed by head-to-toe FDG-PET scanning which revealed foci of metastatic disease in the right mid- thigh and left proximal calf. This case demonstrates the added value of head-to-toe FDG-PET for the detection of distant metastases in MCC.

Merkel cell carcinoma is a rare type of neuroendocrine tumor of the skin with approximately 470 documented new cases annually in the United States. These tumors have high metastatic and recurrence rates, making them aggressive and difficult to treat. Diagnostic workup usually includes computed tomography, magnetic resonance imaging, and scintigraphy methods such as octreotide scans. More recently, positron emission tomographic scanning has been used to evaluate Merkel cell carcinomas. A case of Merkel cell carcinoma, in which positron emission tomography imaging with fluorodeoxyglucose played an important role in staging, re-staging, and identifying previously unknown distant metastatic disease, is presented in this article.

Lymphatic mapping with sentinel lymph node (SLN) biopsy can accurately stage the nodal basins in patients with melanoma of the trunk and extremities and has become a routine, well-accepted diagnostic method for melanoma at these anatomic locations. Melanoma of the head and neck (16% of all cases of melanoma) is complex and difficult to manage because of the rich abundant interlacing lymphatic drainage patterns, as well as watershed areas, which can lead to unusual and unexpected drainage patterns. Radioguided surgery in combination with blue dye facilitates localization of the SLN in the head and neck; however, this type of radioguided surgery is an evolving technique of some difficulty and thus requires careful coordination among the surgeon, nuclear medicine physician, and pathologist. Applications of this technique to other sites in the head and neck are currently being investigated for conditions including squamous cell carcinoma (SCC) of the oral cavity, thyroid cancer, and Merkel cell cancer. More studies of patients with head and neck cancer are needed--and technical issues must be resolved--before radioguided surgery can be recommended as the standard of care for these patients.

Introduction: Lymphatic drainage pathways in the head and neck region are more variable than in any other location of the body. Occasionally, head and neck lymphoscintograms fail to identify a definitive lymphatic drainage pattern, making preoperative and intraoperative identification of sentinel nodes very difficult. The purpose of this study was to determine the incidence of nonlocalization on lymphoscintigraphy of sentinel nodes in patients with head and neck cutaneous malignancies., Methods: A retrospective chart review was conducted of a single surgeon's (WKS) 135 consecutive head and neck melanoma and Merkel cell cancer patients from August 1997 to August 2002. In all cases. technetium-99m sulfur colloid was the radioactive tracer used by the nuclear medicine department to perform the lymphoscintograms., Results: Of the 135 patients, 74 underwent preoperative lymphoscintigraphy in preparation for performing a sentinel lymph node biopsy. Of these 74 patients, 5 (6.8%) were found to have nonlocalization of a sentinel node(s). Of the 5 patients who failed to localize, 3 had primary lesions near the midline scalp, while 2 had primary lesions located on the cheek. Two of the 5 patients underwent reinjection of the radioisotope by the treating surgeon (WKS) but failed to further localize the radiotracer. All 5 patients went on to have wide local excision of the primary cancer on the day of the lymphoscintogram, as well as undergoing intraoperative examination of all head and neck nodal basins with a handheld gamma detector. No focal areas of radiation were identified and no lymph nodes were biopsied. To date, 1 patient has developed distant metastases and has succumbed to her disease. The remaining 4 patients are free of disease., Conclusion: In a series of 135 consecutive patients with head and neck cutaneous malignancies, 74 of whom were treated with preoperative lymphoscintograms, a nonlocalization rate of 6.8% was found. This is a significant rate of nonlocalization and reflects either the inherent difficulty in imaging the head and neck region and/or the possible rapid rate of dye washout via multiple lymphatic drainage pathways that exist in this location.

Objectives/hypothesis: The goals of the research study were to develop an easily mastered, accurate, minimally invasive technique of sentinel node radiolocalization with biopsy (SNRLB) in the feline model; to compare it with blue-dye mapping techniques; and to test the applicability of sentinel node radiolocalization biopsy in three head and neck tumor types: N0 malignant melanoma, N0 Merkel cell carcinoma, and N0 squamous cell carcinoma., Study Design: Prospective consecutive series studies were performed in the feline model and in three head and neck tumor types: N0 malignant melanoma (43 patients), N0 Merkel cell carcinoma (8 patients), and N0 squamous cell carcinoma (20 patients)., Methods: The technique of sentinel node radiolocalization with biopsy was analyzed in eight felines and compared with blue-dye mapping. Patterns of sentinel node gamma emissions were recorded. Localization success rates were determined for blue dye and sentinel node with radiolocalization biopsy. In the human studies, all patients had sentinel node radiolocalization biopsy performed in a similar manner. On the morning of surgery, each patient had sentinel node radiolocalization biopsy of the sentinel lymph node performed using an intradermal or peritumoral injection of technetium Tc 99m sulfur colloid. Sentinel nodes were localized on the skin surface using a handheld gamma detector. Gamma count measurements were obtained for the following: 1) the "hot" spot/node in vivo before incision, 2) the hot spot/node in vivo during dissection, 3) the hot spot/node ex vivo, 4) the lymphatic bed after hot spot/node removal, and 5) the background in the operating room. The first draining lymph node(s) was identified, and biopsy of the node was performed. The radioactive sentinel lymph node(s) was submitted separately for routine histopathological evaluation. Preoperative lymphoscintigrams were performed in patients with melanoma and patients with Merkel cell carcinoma. In patients with head and neck squamous cell carcinoma, the relationship between the sentinel node and the remaining lymphatic basin was studied and all patients received complete neck dissections. The accuracy of sentinel node radiolocalization with biopsy, the micrometastatic rate, the false-negative rate, and long-term recurrence rates were reported for each of the head and neck tumor types. In the melanoma study, the success of sentinel node localization was compared for sentinel node radiolocalization biopsy, blue-dye mapping, and lymphoscintigraphy. In the Merkel cell carcinoma study, localization rates were evaluated for sentinel node radiolocalization biopsy and lymphoscintigraphy. In the head and neck squamous cell carcinoma study, the localization rate of sentinel node radiolocalization biopsy and the predictive value of the sentinel node relative to the remaining lymphatic bed were determined. All results were analyzed statistically., Results: Across the different head and neck tumor types studied, sentinel node radiolocalization biopsy had a success rate approaching 95%. Sentinel node radiolocalization biopsy was more successful than blue-dye mapping or lymphoscintigraphy at identifying the sentinel node, although all three techniques were complementary. There was no instance of a sentinel node-negative patient developing regional lymphatic recurrence. In the head and neck squamous cell carcinoma study, there was no instance in which the sentinel node was negative and the remaining lymphadenectomy specimen was positive., Conclusion: In head and neck tumors that spread via the lymphatics, it appears that sentinel node radiolocalization biopsy can be performed with a high success rate. This technique has a low false-negative rate and can be performed through a small incision. In head and neck squamous cell carcinoma, the histological appearance of the sentinel node does appear to reflect the regional nodal status of the patient.

Background: Merkel cell tumours are rare neoplasms of the skin with frequent regional and distant metastases. Scintigraphy with the radiolabelled somatostatin analogue octreotide is a possible method for in vivo localization of the primary tumour and its metastases., Objectives: To estimate the diagnostic value of indium (111) -octreotide scintigraphy (Octreoscan in detecting metastases., Methods: Scans of 11 patients with Merkel cell carcinoma were evaluated, in whom scintigraphy was performed in addition to the conventional investigations, chest X-ray, ultrasonography and computed tomography (CT)., Results: In four cases metastases were found both by scintigraphy and by conventional methods; two investigations showed a suspicious accumulation of radioactivity on scintigraphy that could not be confirmed by CT and clinical progression. In three cases CT-verified metastases were not found by scintigraphy. Two patients were found to be tumour free, i.e. free of metastases by scintigraphy and conventional methods, indicating true-negative results., Conclusion: These data confirm that scintigraphy with the radiolabelled somatostatin analogue octreotide is not clinically helpful in detecting metastases from Merkel cell carcinoma. In this relatively small sample the method generated false-positive or false-negative results in five of 11 cases.

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine tumor of the skin characterized by frequent local and regional recurrence, a high incidence of distant metastases and therefore a high mortality. Here, we report a case of an oropharyngeal metastasis of a Merkel cell carcinoma of the skin localized at the left base of the tongue causing dysphagia and the sensation of globus pharyngeus. The unusual metastatic site is presented, and diagnosis and treatment are discussed.

Purpose: To determine the feasibility of preoperative lymphoscintigraphy for identification of sentinel lymph nodes (SLNs) in patients with conjunctival and periocular skin tumors and to determine the patterns of lymphatic drainage from such tumors., Methods: We retrospectively reviewed the records of all patients with biopsy-confirmed conjunctival and periocular skin malignancies who underwent lymphoscintigraphy with or without SLN biopsy between January 1999 and June 2000. Patients underwent lymphoscintigraphy with 0.3 to 1 mCi of technetium Tc-99m sulfur colloid in a volume of either 0.2 mL or 1 mL. Images were taken as soon as the first SLNs were detected through the camera and every 15 minutes thereafter. Intraoperative mapping and SLN biopsy was performed 1 to 2 days after lymphoscintigraphy unless the patient refused or there were medical contraindications to the procedure., Results: The study included 7 patients with malignant melanoma of the conjunctiva or periocular skin and 1 patient with Merkel cell carcinoma of the eyelid. On lymphoscintigraphy, at least 1 SLN was identified in 7 of the 8 patients. Although all lesions located in the lateral half of the ocular adnexa drained to at least one SLN in the parotid (preauricular) area, there was some variability in the drainage patterns of lesions located in the medial half of the ocular adnexa. A smaller injection volume (0.2 mL) was adequate for detecting the nodes draining the area of injection and led to less spread of technetium to the surrounding areas. Six patients underwent SLN biopsy. In all but one, the nodes identified during surgery corresponded with those visualized on lymphoscintigraphy., Conclusions: Preoperative lymphoscintigraphy successfully identifies SLNs in most patients with conjunctival and periocular skin malignancies. Smaller injection volumes (0.2 mL) appear to be adequate for identification of the sentinel nodes and lead to less spread to surrounding tissues.

Merkel cell or cutaneous neuroendocrine carcinoma is a malignant tumor with a propensity toward local and systemic recurrence. A new surgical technique, intraoperative lymphatic mapping and selective sentinel lymph node dissection (SSLND), has been demonstrated to have a high predictive value for the detection of metastatic disease in the regional lymphatic basin in cutaneous melanoma. The use of this technology may be particularly useful to accurately stage patients with Merkel cell carcinoma (MCC) because this tumor has a frequent propensity toward regional nodal metastases. Intraoperative lymphatic mapping and SSLND were performed on 6 patients with biopsy-proven MCC. Three patients with MCC had positive disease in the sentinel lymph node(s). SSLND is a feasible technique with minimal procedural morbidity to detect clinically occult disease in patients with MCC.

Background: Somatostatin receptor scintigraphy (SRS) may be of interest for staging Merkel Cell Carcinoma (MCC). This study was undertaken to evaluate the sensitivity and specificity of SRS and to determine its role compared to conventional investigations., Patients and Methods: From 1993 to December 2000, 20 patients (10 females and 10 males, aged from 38 to 88, mean 66 years) were included prospectively. At the time of SRS: 12 patients had been diagnosed as having stage I disease, 6 stage II and 4 stage III. Two patients had two SRS studies during the course of their disease. SRS was performed with Indium-111 pentetreotide (Octreoscan), a radiolabelled somatostatin analogue. Patients were treated according to the clinical stage. A regular follow-up was scheduled every three months., Results: SRS depicted stage I and II MCC tumour sites with an overall sensitivity of 78% (95% confidence interval (CI): 40%-97%) and a specificity of 96% (81%-100%). The histopathological diagnosis was used as the gold standard. Sites visualised by SRS were compared to those detected with conventional modalities and to follow-up data for all stages: SRS visualised four out of five primary tumour sites, six out of eight lymph node sites, no skin metastases (14 sites in 2 patients), two out of three thoracic metastases and zero out of two hepatic metastases. SRS did not influence treatment decision-making in any of the cases., Conclusions: Although SRS seems highly specific in MCC and could be of help in difficult cases, it cannot be recommended for routine evaluation.

Purpose: The aim of this work is to evaluate the capability of Tc99m B Dextran as a lymphoscintigraphic agent in the detection of the sentinel node in skin lesions., Materials and Methods: Forty-one patients with melanomas (39) and Merkel cell tumors (2) had perilesional intradermal injection of Tc99m-Dextran 2 hours before surgery. Serial gamma camera images and a handheld gamma probe were used to direct sentinel node biopsy., Results: In 39/41 patients, lymph channels and 52 sentinel nodes (one to three sentinel nodes/patient) could be visualized. In one patient, with a dorsal melanoma, no lymph channels or lymph nodes could be demonstrated on the images and only minimal radioactivity was found in the regional nodes with the probe. Another patient with a facial lesion failed to demonstrate lymph channels or nodes. No adverse reactions were observed., Conclusion: Tc99m-Dextran provided good definition of lymph channels and sentinel node localization, without the risks related to the use of potentially hazardous labeled materials of biological origin.

Merkel cell carcinoma (MCC) is a rare malignant tumor of the skin and often is diagnosed histologically as lymphoma, melanoma and even metastatic small cell carcinoma of the lung (SCCL). Classified as a neuroendocrine tumor, clinically it originates in the head and neck region and may present with metastatic disease at the time of presentation [1]. Osseous involvement in the past has been described to involve regional facial bones only. We present the first reported MRI findings of distant osseous metastasis from a Merkel cell carcinoma to the lumbosacral spine with associated soft tissue and epidural involvement. Appropriate treatment and patient survival depend on prompt diagnostic imaging for establishment of metastatic disease. Previous reports have advocated CT for diagnosis and staging of distant metastases [2,3]. When spinal involvement is suspected, MRI may be a more suitable modality for assessment of the epidural space and appropriate staging and follow-up in such cases.

Background: Merkel cell carcinoma (MCC) resembles malignant melanoma in several ways. Both are cutaneous lesions of the same embryonic origin. Both have an unpredictable biologic behavior, early regional lymph node involvement, early distant metastases, and high recurrence rate., Objective: To apply the sentinel node technique described for melanoma to MCC in light of the common biologic features of these two tumors., Methods: Preoperative lymphoscintigraphy, intraoperative lymphatic mapping, and sentinel node biopsy and frozen section histology were performed to guide the surgical treatment of three patients with MCC., Results: Application of this approach in patients with MCC is feasible, reproducible, and seems reliable., Conclusion: The use of the sentinel node technique for MCC will reduce the number of unnecessary lymphadenectomies, will enable identification of microscopic metastases to lymph nodes, and will improve the stratification and accrual of patients into adjuvant treatment protocols. It may even lead to a survival benefit.

The authors presented two cases of Merkel cell carcinoma, a rare malignant neoplasm of neuroendocrine origin located in parabasal layer of epithelium. The first described case was 67 year old woman, after resection of primary tumor of eyelid, with metastases in lymph nodes of parotid gland. The second case was 44 year old woman with the primary tumor in retroauricular region. The patient underwent radiotherapy 23 years earlier due to malignant lymphoma. Basing on the available literature the authors discussed clinical and histological features of this malignancy, they stressed the important role of immunohistochemical tests in the diagnosis.

Merkel cell carcinoma (MCC) is an unusual malignant primary skin tumor, having a high incidence of local recurrent, and regional and distant metastasis. Due to its capacity to express somatostatin receptors, it can be detected in vivo with 111In-pentetreotide scintigraphy (Ostreoscan). We present a case of a MCC whose scintigraphy revealed regional metastases of a primary frontal cutaneous tumor that had been removed previously. The results verified a good correlation with clinical, radiological an histopathological findings.

Merkel cell carcinoma (MCC) is a rare cutaneous malignancy characterized by an aggressive clinical behavior with high rates of locoregional and systemic recurrence. Regional disease and distant metastases are associated with poor prognosis. Despite a predisposition of MCC to spread via the lymphatics, prophylactic lymph node dissection in the absence of clinically apparent lymph node involvement is controversial. The value of lymphoscintigraphy in cutaneous melanoma is established in lesions with ambiguous lymphatic drainage patterns. When used with sentinel lymph node biopsy (SLNB), it can identify subjects with occult regional node metastasis. The authors present 2 patients with MCC who underwent regional node staging with lymphoscintigraphy-directed SLNB. Both patients had sentinel nodes that were positive for metastatic disease. In patients with MCC, minimally invasive regional node staging SLNB may be useful in limiting the sequelae of routine lymphadenectomies. Whether early identification and treatment of patients with occult regional node disease can influence survival in MCC is not known.

An 87-yr-old woman diagnosed with recurrent Merkel's cell carcinoma was treated with therapeutic limb perfusion and underwent PET scanning with 18F-fluorodeoxyglucose (FDG). PET studies were obtained before and after treatment to determine the response to the intervention. A baseline whole-body study was obtained to assess the extent and degree of disease activity. This was followed by a repeat PET scan 2 mo. later after treatment with isolated limb chemotherapy with high-dose melphalan and tumor necrosis factor-alpha. The initial scan demonstrated multiple foci of high FDG uptake in the left calf, a left supraclavicular lesion and also detected concurrent keratinizing squamous cell metastasis in the right axilla. A repeat PET study showed complete metabolic resolution of the lesions in the left calf after treatment. FDG PET may be a useful technique for staging Merkel cell carcinoma and for assessing the tumor response after therapy of this rare tumor.

Purpose: To report an unusual case of an intracranial extension of Merkel cell carcinoma originating in the external ear canal and causing neurological deficits., Case Report: An 86-year-old woman, with a 16-month history of an external auditory canal mass, presented with hemiparesis, facial paralysis, and obtundation. Radiographic images showed an intracranial mass extending into the petrous bone., Method: The patient had a craniotomy for intracranial tumor resection with concurrent mastoidectomy for facial nerve decompression and obtundation and hemiparesis were resolved. Residual tumor was subsequently treated with adjuvant radiation therapy, and facial nerve function consequently improved., Conclusion: Merkel cell tumors rarely invade the intracranial compartments. Residual tumor and neurological deficits may respond to adjuvant radiation therapy.

131I-MIBG may be useful in the detection of neuroendocrine tumours. Merkel cell carcinoma is a neuroendocrine tumour of the skin. We evaluated a patient with Merkel cell carcinoma using 123I-MIBG single photon emission computed tomography (SPECT) which demonstrated tumour accumulation of the radiotracer in the right eyelid. This result suggests that 123I-MIBG SPECT may be useful in the evaluation of Merkel cell carcinoma.

Purpose: To compare the accuracy of high resolution endorectal magnetic resonance imaging (EMRI) and endorectal ultrasound (EUS) in the preoperative diagnostic of rectal tumours., Patients and Methods: Twenty-one patients with known rectal tumours underwent MR imaging with an endorectal surface coil and EUS. Transversal EMR images were obtained using fast T2-weighted sequences and pre- and postcontrast T1-weighted images. EUS was performed using a 7.0 MHz transducer. Results of both methods were compared with specimens from the resected tumours., Results: Rectal wall layers were reliably demonstrated with both methods in all patients. EMRI and EUS determined the depth of rectal wall invasion. EMRI and EUS agreed with pathologic findings in 16/21 cases, respectively. In one case each, both methods understaged one tumour. EMRI overstaged an adenoma as a T2-tumour. In three and four patients, respectively, no staging was possible due to technical problems., Conclusion: EMRI and EUS show comparable results in the preoperative T-staging of rectal tumours. Both techniques are not suitable for differentiating benign from malignant lymph nodes accurately. While EMRI is expensive and technically demanding, it allows an objective documentation of pathological findings which is less dependent on the examiner. Two important clinical conclusions can be drawn from the good results of T-staging: Adenomas and T1-tumours can be treated by local excision. In patients with advanced tumours (T3/T4) a neoadjuvant therapy can be initiated.

Merkel cell carcinoma (MCC) is a rare cutaneous skin lesion with a variable but often aggressive clinical course. Patient survival correlates with nodal status and the presence of distant metastases. The histologic status of the sentinel lymph node consistently correlates with the incidence of regional lymphatic metastases in other dermal malignancies. The technique of radiolocalization and surgical resection of the sentinel lymph node using an intraoperative gamma probe is used to guide clinical management in these patients. We report on seven cases of MCC managed utilizing this technique. Four patients had negative sentinel nodes and no other nodal disease at completion lymphadenectomy (n = 2) or clinical follow-up (n = 2) and currently remain disease free. Two patients had a positive sentinel node but no other positive lymph nodes at completion lymphadenectomy; one of them developed regional recurrence. One patient with a positive sentinel node and six additional positive nodes developed extensive nodal disease and systemic recurrence during radiotherapy and expired of MCC. Our results suggest that the sentinel node was identified and removed successfully using radiolocalization making this technique useful in the staging and therapy of patients with MCC.