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A defining pathological feature of human lung fibrosis is localized tissue heterogeneity, which challenges the interpretation of transcriptomic studies that typically lose spatial information. Here we investigate spatial gene expression in diagnostic tissue using digital profiling technology. We identify distinct, region-specific gene expression signatures as well as shared gene signatures. By integration with single-cell data, we spatially map the cellular composition within and distant from the fibrotic niche, demonstrating discrete changes in homeostatic and pathologic cell populations even in morphologically preserved lung, while through ligand-receptor analysis, we investigate cellular cross-talk within the fibrotic niche. We confirm findings through bioinformatic, tissue, and in vitro analyses, identifying that loss of NFKB inhibitor zeta in alveolar epithelial cells dysregulates the TGFβ/IL-6 signaling axis, which may impair homeostatic responses to environmental stress. Thus, spatially resolved deconvolution advances understanding of cell composition and microenvironment in human lung fibrogenesis.

In routine surgical pathology lymphoid proliferations are seen fairly frequently. It is important to be aware of commonly seen reactive and inflammatory pathologies, as well as malignant lymphomas of the MALT tissue and nodal involvement by lymphomas. Several of the reactive pathologies have striking morphological features such that haematoxylin and eosin stained slides are sufficient in arriving at a diagnosis. There are several pathological entities in which Ebstein-Barr virus has a role to play, including both benign and malignant proliferations. Most high-grade lymphomas have a worrying morphological appearance and immunohistochemistry is helpful in confirming the diagnosis. More problematic are dense lymphoid infiltrates where the differential diagnosis lies between a reactive versus a low grade lymphoma; immunohistochemistry is vital in such situations. In addition, there are entities specific to the head and neck region, such as an extranodal NK/T-cell lymphoma, nasal type. Careful clinical and radiological correlation is vital.

Ipilimumab is an anti-CTLA4 antibody in evaluation for the treatment of small cell lung cancer. We report a case of rapidly progressive fatal cerebellitis occurring eight months after first dosing. Pre-treatment weakly positive anti-Yo antibodies did not change. Clinically asymptomatic anti-voltage-gated calcium channel antibodies developed after ipilimumab treatment, despite lack of expression by the tumour. The patient died three weeks into the neurological illness. Post-mortem examination revealed a T cell-mediated cerebellitis, with CD8 cytotoxicity towards Purkinje cells. This demonstrates the potential for CD8 T cells to trigger neuronal autoimmunity, offering insight into the early events in paraneoplastic neurological disease.remi.guillochon@nhs.net

Tuberculosis (TB) is a persistent global pandemic, and standard treatment for it has not changed for 30 years. Mycobacterium tuberculosis (Mtb) has undergone prolonged coevolution with humans, and patients can control Mtb even after extensive infection, demonstrating the fine balance between protective and pathological host responses within infected granulomas. We hypothesized that whole transcriptome analysis of human TB granulomas isolated by laser capture microdissection could identify therapeutic targets, and that comparison with a noninfectious granulomatous disease, sarcoidosis, would identify disease-specific pathological mechanisms. Bioinformatic analysis of RNAseq data identified numerous shared pathways between TB and sarcoidosis lymph nodes, and also specific clusters demonstrating TB results from a dysregulated inflammatory immune response. To translate these insights, we compared 3 primary human cell culture models at the whole transcriptome level and demonstrated that the 3D collagen granuloma model most closely reflected human TB disease. We investigated shared signaling pathways with human disease and identified 12 intracellular enzymes as potential therapeutic targets. Sphingosine kinase 1 inhibition controlled Mtb growth, concurrently reducing intracellular pH in infected monocytes and suppressing inflammatory mediator secretion. Immunohistochemical staining confirmed that sphingosine kinase 1 is expressed in human lung TB granulomas, and therefore represents a host therapeutic target to improve TB outcomes.

ADAPTeR is a prospective, phase II study of nivolumab (anti-PD-1) in 15 treatment-naive patients (115 multiregion tumor samples) with metastatic clear cell renal cell carcinoma (ccRCC) aiming to understand the mechanism underpinning therapeutic response. Genomic analyses show no correlation between tumor molecular features and response, whereas ccRCC-specific human endogenous retrovirus expression indirectly correlates with clinical response. T cell receptor (TCR) analysis reveals a significantly higher number of expanded TCR clones pre-treatment in responders suggesting pre-existing immunity. Maintenance of highly similar clusters of TCRs post-treatment predict response, suggesting ongoing antigen engagement and survival of families of T cells likely recognizing the same antigens. In responders, nivolumab-bound CD8+ T cells are expanded and express GZMK/B. Our data suggest nivolumab drives both maintenance and replacement of previously expanded T cell clones, but only maintenance correlates with response. We hypothesize that maintenance and boosting of a pre-existing response is a key element of anti-PD-1 mode of action.

International audience; Although thousands of solid tumors have been sequenced to date, a fundamental under-sampling bias isinherent in current methodologies. This is caused by a tissue sample input of fixed dimensions (e.g., 6 mmbiopsy), which becomes grossly under-powered as tumor volume scales. Here, we demonstrate representative sequencing (Rep-Seq) as a new method to achieve unbiased tumor tissue sampling. Rep-Seq uses fixed residual tumor material, which is homogenized and subjected to next-generation sequencing. Analysis of intratumor tumor mutation burden (TMB) variability shows a high level of misclassification using current single-biopsy methods, with 20% of lung and 52% of bladder tumors having at least one biopsy with high TMB butlow clonal TMB overall. Misclassification rates by contrast are reduced to 2% (lung) and 4% (bladder) when a more representative sampling methodology is used. Rep-Seq offers an improved sampling protocol for tumor profiling, with significant potential for improved clinical utility and more accurate deconvolution of clonal structure.

Previously, we developed a 3-dimensional cell culture model of human tuberculosis (TB) and demonstrated its potential to interrogate the host-pathogen interaction (Tezera et al., 2017a). Here, we use the model to investigate mechanisms whereby immune checkpoint therapy for cancer paradoxically activates TB infection. In patients, PD-1 is expressed in Mycobacterium tuberculosis (Mtb)-infected lung tissue but is absent in areas of immunopathology. In the microsphere model, PD-1 ligands are up-regulated by infection, and the PD-1/PD-L1 axis is further induced by hypoxia. Inhibition of PD-1 signalling increases Mtb growth, and augments cytokine secretion. TNF-α is responsible for accelerated Mtb growth, and TNF-α neutralisation reverses augmented Mtb growth caused by anti-PD-1 treatment. In human TB, pulmonary TNF-α immunoreactivity is increased and circulating PD-1 expression negatively correlates with sputum TNF-α concentrations. Together, our findings demonstrate that PD-1 regulates the immune response in TB, and inhibition of PD-1 accelerates Mtb growth via excessive TNF-α secretion.

Mucoepidermoid variant of thyroid carcinoma is a rare and complex disease. Securing a diagnosis and formulating an evidence-based treatment plan is challenging. A case report of a patient with the dual pathology of a composite mucoepidermoid carcinoma of the thyroid and a follicular variant of papillary thyroid carcinoma with malignant metastasis is presented in this article. We discuss the challenges in diagnosis, prognostic factors and management of this rare presentation by reviewing current literature.

Aims Immunoglobulin (Ig)G4-related disease (IgG4-RD) is an increasingly recognized fibroinflammatory condition that commonly exhibits multisystem involvement, with localized (e.g. inflammatory pseudotumours that can mimic malignancy) or diffuse (leading to organ dysfunction) patterns of tissue involvement. The 2012 Boston criteria have standardized the histopathological approach to the diagnosis of IgG4-RD and require one or more of the cardinal morphological features with prominence of IgG4+ plasma cells and an IgG4+/IgG+ plasma cell ratio of at least 40%. The relative prevalence of the morphological criteria varies between anatomical sites, but granulomas are rarely found and, indeed, their presence would usually deter a pathologist from making this diagnosis. The aim was to characterize two cases of IgG4-RD in which granulomas were present and to highlight this as an unusual feature of the condition. Methods and results We describe two cases in which the features of IgG4-RD were present within lymph nodes, together with granulomas. This is a recognized but rare morphological pattern of IgG4-RD. Conclusions While an unusual finding, the presence of granulomas should not preclude a diagnosis of IgG4-RD in the appropriate clinicopathological context.

Development of distant metastases from renal cell carcinoma (RCC) is a frequent occurrence and, in nearly 95% of the cases, secondary lesions present within 5 years following nephrectomy. We performed a left pneumonectomy for a peri-hilar lung mass in an 81-year-old man with history of kidney cancer, resected 37 years earlier. Histopathological examination revealed a solitary lung metastasis from RCC, relapsed after an extraordinary 37-year time interval. To the best of our knowledge, this remarkable case represents the longest time interval between radical nephrectomy for RCC and the occurrence of a pulmonary metastasis. After an uneventful post-operative recovery, there are no signs of disease recurrence at a 3-year follow-up. The possibility of a lung metastasis should be taken into account in patients with history of RCC who present with pulmonary nodules, even decades after treatment of the primary neoplasm.

Background: Human papillomavirus (HPV)-positive oropharyngeal cancer (OPSCC) is associated with improved survival compared with HPV-negative disease. However, a minority of HPV-positive patients have poor prognosis. Currently, there is no generally accepted strategy for identifying these patients.Methods: We retrospectively analysed 270 consecutively treated OPSCC patients from three centres for effects of clinical, pathological, immunological, and molecular features on disease mortality. We used Cox regression to examine associations between factors and OPSCC death, and developed a prognostic model for 3-year mortality using logistic regression analysis.Results: Patients with HPV-positive tumours showed improved survival (hazard ratio (HR), 0.33 (0.21–0.53)). High levels of tumour-infiltrating lymphocytes (TILs) stratified HPV-positive patients into high-risk and low-risk groups (3-year survival; HPV-positive/TILhigh=96%, HPV-positive/TILlow=59%). Survival of HPV-positive/TILlow patients did not differ from HPV-negative patients (HR, 1.01; P=0.98). We developed a prognostic model for HPV-positive tumours using a ‘training’ cohort from one centre; the combination of TIL levels, heavy smoking, and T-stage were significant (AUROC=0·87). This model was validated on patients from the other centres (detection rate 67%; false-positive rate 5.6%; AUROC=0·82).Interpretation: Our data suggest that an immune response, reflected by TIL levels in the primary tumour, has an important role in the improved survival seen in most HPV-positive patients, and is relevant for the clinical evaluation of HPV-positive OPSCC.

Cell biology differs between traditional cell culture and 3-dimensional (3-D) systems, and is modulated by the extracellular matrix. Experimentation in 3-D presents challenges, especially with virulent pathogens. Mycobacterium tuberculosis (Mtb) kills more humans than any other infection and is characterised by a spatially organised immune response and extracellular matrix remodelling. We developed a 3-D system incorporating virulent mycobacteria, primary human blood mononuclear cells and collagen–alginate matrix to dissect the host-pathogen interaction. Infection in 3-D led to greater cellular survival and permitted longitudinal analysis over 21 days. Key features of human tuberculosis develop, and extracellular matrix integrity favours the host over the pathogen. We optimised multiparameter readouts to study emerging therapeutic interventions: cytokine supplementation, host-directed therapy and immunoaugmentation. Each intervention modulates the host-pathogen interaction, but has both beneficial and harmful effects. This methodology has wide applicability to investigate infectious, inflammatory and neoplastic diseases and develop novel drug regimes and vaccination approaches.

Tuberculosis remains a global pandemic and drives lung matrix destruction to transmit. Whilst pathways driving inflammatory responses in macrophages have been relatively well described, negative regulatory pathways are less well defined. We hypothesised that Mycobacterium tuberculosis (Mtb) specifically targets negative regulatory pathways to augment immunopathology. Inhibition of signalling through the PI3K/AKT/mTORC1 pathway increased matrix metalloproteinase-1 (MMP-1) gene expression and secretion, a collagenase central to TB pathogenesis, and multiple pro-inflammatory cytokines. In patients with confirmed pulmonary TB, PI3Kδ expression was absent within granulomas. Furthermore, Mtb infection suppressed PI3Kδ gene expression in macrophages. Interestingly, inhibition of the MNK pathway, downstream of pro-inflammatory p38 and ERK MAPKs, also increased MMP-1 secretion, whilst suppressing secretion of TH1 cytokines. Cross-talk between the PI3K and MNK pathways was demonstrated at the level of eIF4E phosphorylation. Mtb globally suppressed the MMP-inhibitory pathways in macrophages, reducing levels of mRNAs encoding PI3Kδ, mTORC-1 and MNK-1 via upregulation of miRNAs. Therefore, Mtb disrupts negative regulatory pathways at multiple levels in macrophages to drive a tissue-destructive phenotype that facilitates transmission., Author summary The mechanisms whereby Mycobacterium tuberculosis (Mtb) evades host immunity are well described, but Mtb must also engage the host immune response to drive tissue destruction, cavitation and transmission as part of its life cycle. We identify negative regulatory pathways that suppress pathogenic matrix metalloproteinase-1 expression in primary human macrophages, including a previously unidentified role of the MAP kinase-interacting kinase (MNK) pathway in inhibiting protease secretion. Furthermore, these pathways are suppressed in granulomas of patients with culture-proven pulmonary tuberculosis and in infected macrophages in vitro. Stability of mRNA encoding negative regulatory molecules is reduced, and Mtb upregulates multiple microRNAs predicted to target their 3’UTR. Together, these findings demonstrate that Mtb skews the macrophage phenotype towards tissue destruction by disrupting negative regulatory pathways.

A 52-year-old Caucasian man, previously healthy except for a sickle cell trait, developed severe night sweats followed 4 months later by priapism and then, over 1 week, a gradual painless binocular reduction in vision. His visual acuity was 0.98 (right) and 0.9 (left) logMAR. There was no vitreous activity and retinal examination was normal. Fluorescein angiography showed leakage from vasculature in the superficial choroid but vessel calibre was normal. Optical coherence tomography showed multiple serous retinal detachments. Inflammatory causes were high on the list of ophthalmological differential diagnoses, and he was treated with 3 days of 500 mg intravenous methylprednisolone followed by oral prednisolone 40 mg. Two weeks later, he developed increasing low back pain with radiation to his thighs, followed by numbness of his perianal region, buttocks and posterior thighs, with urinary retention and faecal incontinence. Over the next 3 days he developed progressively ascending bilateral leg weakness. His pain became extremely difficult to control. On examination, there were signs of a cauda equina syndrome. The weakness initially affected the muscles supplied by L5–S1 roots, with sensory disturbance in an S2–S5 distribution, but this rapidly progressed to a complete paraplegia with absent sensation to all modalities from L2 downwards. His legs were flaccid and areflexic. He had a swinging temperature up to 39°C. MRI of the spine showed thickening of the lumbosacral nerve roots, which enhanced with contrast (figure 1). He had raised inflammatory markers (erythrocyte sedimentation rate 46 mm per first hour (

Objective To assess the diagnostic accurdcy of fine needle aspiration cytology (FNAC) in the diagnosis of Hodgkin's lymphoma (HI.). Study Design We selected all the cases in which ii cytologic diagnosis of HI., suggestive of or suspicious for HI., or HI. as the prime differential diagnosis was of-fered on FNAC. These cases were correleated with bistopathologic follow-up Cases of primary HI. diagnosed on cytology but without bistopathology were excluded from the study. Results Histopathologic follow-up was avalable in 46 cases. Of these, 42 were correctly diagnosed as HL, and there was a discorrelation in 4 cases, comprising 3 cases of non-HL (T-cell-rich B-cell lymphoma [TCRBCL]-2. anaplastic large cell lymphoma-1) and 1 case of metastatic carcinoma. Overall accuracy was 91.3%. In 14 cases, the cytologic features were diagnostic of recurrence; bence, no histopathologic examination was done. No folow-up was available for the remaining 19 cases, which "were excluded from the study. Conclusion FNAC is very useful for rapid and accurate approach to the diagnosis of recurrent and most cases of primary HI., Because of morphologic similarities, it is difficult to differntiate HI, from anaplastic large cell lymphoma and TCRBCL on ENAC. It is advisable to request a histopathologic examination in all cases of primary HI.

Objective To analyze the diagnostic efficacy of fine needle aspiration cytology (FNAC) in the initial evaluation of thyroid midules, with special emphasis on discrepant cytologic diagnoses. Study Design A total of 192 thyroid fine needle aspirates with subsequent histopathologic follow-up were analyzed. The cytologic diagnoses were divided into 4 categories: positive for malignancy, negative for malignancy, indeterminate for diagnosis and nondiagnostic. The detailed cytologic features were studied along with histopathology sections in all these cases by 2 observers (S. J. and P.D.) independently. Results Cytohistologic correlation was seen in 78.1 % of cases and discordance in 21.9%. Indeterminate diagnoses accounted for 15.1% of cases. The majority of these were follicular neoplasms. The overall sensitivity was 84.44% and specificity 99.11%. A false positive diagnosis was made in 1 case (0.5 %), proven a follicular adenoma on histopathologic examination. A fnlse negative diagnosis was seen in 3.6% of cases. These were cases of papillary microcarcinoma. Conclusion FNAC is a safe, sensitive and specific technique in the initial evaluation of thyroid nodules. A correct cytologic diagnosis can be achieved in a majority of cases, thus obviating the need for a second surgical intervention. A careful and diligent search for various cytologic features and accurate sampling can help in reducing the number of indeterminate, false positive and false negative diagnoses.

In this article we described the fine-needle aspiration cytology (FNAC) of five cases of metastatic transitional cell carcinoma (TCC). There were four cases of metastatic lymph nodes and one case of metastatic skin lesion. All of the TCC cases were primarily in the urinary bladder and were high grade on histopathology (grade 3). Three cases showed bladder muscle involvement and two cases showed superficial TCC at the time of primary diagnosis. FNAC smears showed abundant cellularity. The cells were present in discrete and small syncytial clusters. Nuclear position of the cell was central to eccentric. Many cells showed prominent nucleoli. Cercariform cells (CCs) were noted in four cases. These cells are malignant cells with a nucleated globular body and a unipolar nontapering cytoplasmic process. Two cases showed intranuclear inclusions. Prominent cytoplasmic vacuoles were noted in three cases. In addition, cell cannibalism and attempted pearl formations were noted in two cases.In conclusion, clinical history along with the certain cytological features such as the presence of CCs, cells with eccentric nuclei, and intranuclear inclusions are helpful to diagnose metastatic TCC on FNAC material.

BACKGROUND: Epithelioid sarcoma is a rare type of soft tissue sarcoma affecting the extremities, particularly the hands and fingers. Though it is well described histopathologically, publications regarding its cytologic findings are limited. CASE: A 52-year-old woman presented with swelling of the left middle finger. Fine needle aspiration was performed. Smears showed oval to polygonal cells with epithelioid features. A diagnosis of soft tissue sarcoma with a possibility of epithelioid sarcoma was suggested. Histopathologic examination and immunohistochemistry confirmed the diagnosis. CONCLUSION: In the presence of classic cytologic findings, the diagnosis of epithelioid sarcoma can be suggested. Subsequent histologic examination and immunohistochemistry can confirm the diagnosis.

OBJECTIVES The aim of this study is to investigate the role of routine systematic mediastinal nodal dissection (SND) performed during video-assisted thoracic surgery (VATS) major pulmonary resections (VMPRs) as a staging strategy for non-small-cell lung cancer (NSCLC), compared with preoperative staging by conventional positron emission tomography (PET) and computed tomography (CT) imaging. METHODS All patients suspected of having early lung cancer (T1-2, N0-1 and M0) were staged preoperatively by CT/PET. During VMPR, all lymph nodes on the right side at stations 2-4, 7, 8, 9, 10 and 11 and on the left stations 4-6, 7, 8, 9, 10, 11 and 3 when indicated were dissected en bloc. Histology was provided on the paraffin-embedded nodes, and patients staged accordingly. Preoperative and postoperative stagings were compared. Stage migration and impact on clinical pathway were noted. Stage IIa and higher were referred for adjuvant chemotherapy. RESULTS Between April 2007 and January 2011, 106 consecutive patients with suspected primary NSCLC proceeded to VMPR+SND. Histology confirmed NSCLC in 96 patients. Forty-five were men and 51 women. Median age was 68.6 (range 42.8-84.7) years. As many as 91 (94.8%) patients underwent lobectomy, three (3.1%) bilobectomy and two (2.1%) pneumonectomy. PET accurately correlated with SND histological diagnosis in 42 (43.8%) patients. The unexpected N2 disease in cN0-1 was 9/86 (10.5%). SND resulted in 25 stage migrations, upstaged 16 (16.6%) and down-staged nine (9.4%) patients. All upstagings were adenocarcinoma. Four (4.2%) PET-negative patients had multi-station N2 disease. SND resulted in changing the clinical pathway for 19 (20%) patients. Fourteen (14.6%) patients upstaged to qualify for chemotherapy, and 5/9 (5.2%) down-staged patients were saved the chemotherapy. There was no morbidity or mortality attributable to this added procedure. CONCLUSIONS SND during VMPR is safe and should be routinely performed even when nodal metastases is considered unlikely. VATS-SND is more accurate than PET in staging the mediastinum for NSCLC. PET sensitivity is significantly reduced in adenocarcinoma and might result in stage migration. Adjuvant multidisciplinary treatment should be based on SND staging.

To assess the diagnostic accuracy offine needle aspiration cytology (FNAC) in the diagnosis of Hodgkin's lymphoma (HL).We selected all the cases in which a cytologic diagnosis of HL, suggestive of or suspicious for HL, or HL as the prime differential diagnosis was offered on FNAC. These cases were correlated with histopathologic follow-up. Cases of primary HL diagnosed on cytology but without histopathology were excluded from the study.Histopathologic follow-up was available in 46 cases. Of these, 42 were correctly diagnosed as HL, and there was a discorrelation in 4 cases, comprising 3 cases of non-HL (T-cell-rich B-cell lymphoma [TCRBCL]-2, anaplastic large cell lymphoma-1) and 1 case of metastatic carcinoma. Overall accuracy was 91.3%. In 14 cases, the cytologic features were diagnostic ofrecurrence; hence, no histopathologic examination was done. No follow-up was available for the remaining 19 cases, which were excluded from the study.FNAC is very useful for rapid and accurate approach to the diagnosis of recurrent and most cases of primary HL. Because of morphologic similarities, it is difficult to differentiate HL from anaplastic large cell lymphoma and TCRBCL on FNAC. It is advisable to request a histopathologic examination in all cases of primary HL.

OBJECTIVE To assess the efficacy of fine needle aspiration cytology (FNAC) in the diagnosis of nodular sclerosis variant of Hodgkin's lymphoma (NSHL) and to analyze cytologic features that could help in subtyping a case of Hodgkin's lymphoma into this variant. STUDY DESIGN FNAC smears of 18 histopathologically proven cases of NSHL were analyzed for a variety of features. RESULTS On initial cytologic assessment, 14 of 18 cases were diagnosed as Hodgkin's lymphoma. No further subtyping was performed. In this retrospective analysis it was possible to revise the diagnosis in the remaining 4 cases. Of the various cytologic features analyzed, presence of numerous lacunar-type cells along with fibroblasts and collagenous material were useful pointers toward a diagnosis of nodular sclerosis variant. Fibroblasts were seen in 83.33%, collagenous material in 27.77% and numerous lacunar cells in 77.77%. CONCLUSION Subtyping of NSHL based on cytologic features alone has been a matter of debate for a long time. Of the various subtypes, nodular sclerosis poses the greatest diagnostic difficulty. Though certain cytologic features may help in suggesting a diagnosis of nodular sclerosis variant, the primary role of fine needle aspiration is to diagnose a case of Hodgkin's lymphoma as such and advise histopathologic examination for further categorization.

The cytological diagnosis of classical papillary carcinoma is easily established based on the characteristic architectural and nuclear features. However, the follicular variant of papillary thyroid carcinoma(FVPTC) poses a diagnostic challenge. In this study we analysed the cytological features of 14 histopathologically proven cases of FVPTC. We inferred that a combination of architectural features such as follicles and syncytial clusters and nuclear features, viz grooves, pseudoinclusions and enlarged nuclei with fine chromatin, were helpful in establishing the diagnosis. It is hence suggested that based on the combination of the aforesaid features a diagnosis of FVPTC be offered whenever it is possible. This helps in patient management, obviating the need for a second surgical intervention.

Objective: To report a case of sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease) in an extranodal site with unusual presentation. Case Presentation: A 19-year-old girl presented with bilateral upper eyelid swellings of 2 years duration due to tumor. The masses were excised and sent for histopathological examination. Microscopic examination revealed similar features in both masses in the form of a collection of large histiocytic cells showing emperipolesis (lymphocytophagocytosis). The histiocytic cells stained positively with S-100 protein and CD68. The background comprised small lymphocytes and plasma cells. Based on the overall features a diagnosis of sinus histiocytosis with massive lymphadenopathy or Rosai-Dorfman disease was made. Conclusion: The present case highlights one of the forms in which extranodal Rosai-Dorfman disease can manifest itself. It is important to keep this differential diagnosis in mind whenever such histopathological features are encountered.

A case of malignant Leydig cell tumour is presented. It is a rare primary malignant tumour of the testis and occurs exclusively in adults. The present case is of interest because it occurred at the young age of 25 years which is rare. Histologically it showed almost all features which suggest malignancy and also had metastases to the lungs and liver. The clinical details and pathology of this tumour are discussed.

Aims and objectives: In this present study we have evaluated the feasibility of sub-classification of non-Hodgkin's lymphoma (NHL) cases according to World Health Organization's (WHO) classification on fine needle aspiration cytology (FNAC) material along with flow cytometric immunotyping (FCI) as an adjunct. Materials and methods: In this five years study, only cases suggested or confirmed as NHL by FNAC were selected and FCI was performed with a complete panel of antibodies (CD3, CD2, CD 4, CD5, CD8, CD7, CD10, CD19, CD20, CD23, CD45, κ and λ) by dual color flow cytometry. Both cytologic findings and FCI data were interpreted together to diagnose and sub-classify NHL according to WHO classification. Wherever possible the diagnoses were compared with cytology. Results: There were total 48 cases included in this study. The cases were classified on FNAC as predominant small cells (12), mixed small and large cells (5) and large cells (26). In five cases a suggestion of NHL was offered on FNAC material and these cases were labeled as NHL not otherwise specified (NHL-NOS). Flow cytometry could be performed in 45 cases (93.8%) and in rest of the three cases the material was inadequate because of scanty blood mixed aspirate. Light chain restriction was demonstrated in 30 cases out of 40 cases of B-NHL (75%). There were 15 cases each of ? and ? light chain restriction in these 30 cases. With the help of combined FCI and FNAC, it was possible to sub-classify 38 cases of NHL (79%) according to WHO classification. Combined FNAC and FCI data helped to diagnose 9 cases of small lymphocytic lymphoma (SLL), 2 cases of mantle cell lymphoma (MCL), 4 cases of follicular lymphoma (FL), 17 cases of diffuse large B lymphoma (DLBL) and 6 cases of lymphoblastic lymphoma. Histopathology diagnosis was available in 31 cases of NHL out of which there were 14 recurrent and 17 cases of primary NHL. Out of 15 DLBL cases diagnosed on FCI and FNAC, histology confirmed 14 cases and one of these cases was diagnosed as Burkitt's lymphoma on histology. Cases of FL (4), SLL (3) and MCL (2) were well correlated with histopathology. Out of the five cases suggestive of NHL on cytology, histopathology was available in four cases. Histology diagnosis was given as DLBL (1), SLL (1), anaplastic large cell lymphoma (1) and FL transformed into large cell NHL (1). Considering histopathology as gold standard, diagnostic specificity of combined FNAC and FCI was 100% (31/31) and sensitivity in sub-classification was 83.8% (26/31). Conclusion: FNAC combined with FCI may be helpful in accurately sub-classifying NHL according to WHO classification. Many of the subtypes of NHL such as FL and MCL which were previously recognized as a pure morphologic entity can be diagnosed by combined use of FNAC and FCI. Other ancillary investigations such as chromosomal changes, cell proliferation markers etc. may be helpful in this aspect.