Comparison of Muscle Biopsy Features with Myositis Autoantibodies in Inflammatory Myopathies: A Pilot Experience.

Background: Idiopathic inflammatory myopathies (IIM), also called autoimmune myositis, are heterogeneous. These include dermatomyositis (DM), inclusion body myositis, immune mediated necrotizing myopathy (IMNM), anti-synthetase syndrome (ASS), and overlap polymyositis. Classification of IIM has evolved from clinical to clinico-pathologic to the recent clinico-sero-pathologic with the discovery of myositis-specific antibodies (MSA) and myositis-associated antibodies. The various antibodies have shown association with specific phenotypes. Objective: To analyze muscle biopsy features with respect to each MSA and MAA to understand the frequency of findings in each entity. Materials and Methods: Biopsy-proven cases of IIM where myositis profile was available were included in the study after obtaining Institutional Ethics Committee (IEC) approval. In addition to the stains and enzyme histochemistry, immunohistochemistry with MHC class I and II and MxA was performed. Features like perifascicular atrophy, perifascicular necrosis, scattered necrosis, inflammation, etc. were analyzed. Myositis profile was performed by line-blot technique using a 16-antigen panel. Cases were divided into different autoantibody subgroups. Various clinical, demographic, and muscle biopsy features were studied with respect to each MSA and MAA. Results: There were a total of 64 cases. Mi2 (N = 18) was the most common autoantibody. Some of the salient observations included PFA with perivascular inflammation in Mi2; pediatric cases and microinfarcts in NXP2; no PFA or inflammation in MDA5; perifascicular necrosis in JO1; extensive necrosis with sparse inflammation in SRP; more inflammation in overlap myositis; MxA positivity in DM; and absent in ASS. Conclusion: This is a pilot study documenting differences in biopsy phenotype with each MSA and MAA which is comparable to the literature. These findings can be used to characterize IIM in seronegative biopsies.

Clinicomorphological and molecular analysis of medulloblastoma and association with survival: A single tertiary care center experience.

BACKGROUND: Medulloblastoma (MB) is a heterogeneous disease, displaying distinct genetic profiles, with specific molecular subgroups. Various clinical, pathological and molecular variables have been associated with disease outcome and therefore utilised in risk stratification of patients. OBJECTIVES: To perform molecular classification of medulloblastoma using surrogate immunohistochemistry (IHC) and associate molecular subgroups, histopathological types, and available clinicopathological parameters with overall survival (OS) of MB patients. RESULTS: This study included 65 medulloblastoma patients. Immunohistochemical staining, using ß-catenin YAP1 and GRB2-Associated Binding Protein 1 (GAB1) antibodies was used to classify MB cases into wingless signalling (WNT) activated, sonic hedgehog (SHH) activated, and non-WNT/non-SHH molecular subgroups. The relevant statistical analysis was done using GraphPad Prism version 9.3.0. Histological patterns included classic (40 cases, 62%), desmoplastic nodular (D/N) (14 cases, 22%), large cell/anaplastic (LC/A) (9 cases, 13%), medulloblastoma with extensive nodularity (MBEN) (1 case, 1.5%) and one special subtype, i.e., medulloblastoma with myogenic and melanotic differentiation. Molecular subgroups included WNT (4 cases, 6%), SHH (34 cases, 52%), and non-WNT/non-SHH (27 cases, 42%) subgroups. Histopathological types differed significantly according to tumor location, degree of anaplasia and molecular subgroups. Molecular subgroups differed significantly in age distribution and tumor location. The probability of survival was 78% and 68% after 1 and 2 years, respectively. Infants (<3 years of age), LC/A pattern, and TP53-mutant status among SHH subgroup conferred poor prognosis in our study. At the end of the study (at 65 months of maximum follow-up period) probability of survival was 51%. CONCLUSIONS: Immunohistochemical analysis helps in molecular classification of medulloblastoma in majority of the cases as well as helps in predicting prognosis and treatment response.

Endocrine mucin-producing sweat gland carcinoma of the peno-scrotum with systemic metastases: A rare case report.

Endocrine mucin-producing sweat gland carcinoma (EMPSGC) is a rare adnexal tumor with a predilection for the skin of the eyelid. It has also been reported in other areas of the face. Extra facial location has rarely been reported. They are twice as common in the females as compared to men and frequently affect the elderly between 50 and 80 years of age. It is a low-grade carcinoma with no reported cases of metastases, although a few cases with recurrences have been reported. Since it was first described by Flieder et al. in 1997, fewer than 60 cases have been reported in the literature. We describe one such case of EMPSGC in an adult male occurring at an unusual location, the peno-scrotal junction with systemic metastases to bilateral inguinal and iliac lymph nodes, multiple bones, and pancreas. Unlike previously reported cases, our patient worsened rapidly and succumbed to the disease six months after initiation of chemotherapy and radiotherapy. To the best of our knowledge, this is the first reported case of its kind in modern published literature.

Revisiting renal amyloidosis with clinicopathological characteristics, grading, and scoring: A single-institutional experience.

INTRODUCTION: Kidney involvement is a major cause of mortality in systemic amyloidosis. Glomerulus is the most common site of deposition in renal amyloidosis, and nephrotic syndrome is the most common presentation. Distinction between AA and AL is done using immunofluorescence (IF) and immunohistochemistry (IHC). Renal biopsy helps in diagnosis and also predicting the clinical course by applying scoring and grading to the biopsy findings. MATERIALS AND METHODS: The study includes all cases of biopsy-proven renal amyloidosis from January 2008 to May 2017. Light microscopic analysis; Congo red with polarization; IF; IHC for Amyloid A, kappa, and lambda; and bone marrow evaluation were done. Classification of glomerular amyloid deposition and scoring and grading are done as per the guidelines of Sen S et al. RESULTS: There are 40 cases of biopsy-proven renal amyloidosis with 12 primary and 23 secondary cases. Mean age at presentation was 42.5 years. Edema was the most common presenting feature. Secondary amyloidosis cases were predominant. Tuberculosis was the most common secondary cause. Multiple myeloma was detected in four primary cases. Grading of renal biopsy features showed a good correlation with the class of glomerular involvement. CONCLUSION: Clinical history, IF, and IHC are essential in amyloid typing. Grading helps provide a subtle guide regarding the severity of disease in the background of a wide range of morphological features and biochemical values. Typing of amyloid is also essential for choosing the appropriate treatment.