Pituitary blastoma, expanding the spectrum of newly recognized entities. A case report

Tumors of the pituitary gland and sellar region represent about 15% of all brain tumors, with pituitary adenoma being the commonest and pituitary carcinoma being very rare. Pituitary tumors in children are even rarer. Pituitary blastoma, a pediatric adenohypophysial tumor, is a new entity described in the 2017 WHO classification of pituitary tumors. This is a very rare tumor with only 21 cases reported so far. Hence, we are reporting this unusual case seen in a 7-month-old infant who presented with a large sellar/suprasellar mass with pressure symptoms of short duration. Typically, they present between 7–24 months of age. On histopathology, a cellular tumor was seen with primitive-looking round cells with scanty cytoplasm with few well-defined gland or rosette-like structures. The immunohistochemical stains showed diffuse strong staining for synaptophysin with a very high MIB-1 index. Other markers for common round cell tumors in this age group and hormonal markers of pituitary tumors were negative with INI-1 being intact. The initial cases described by Scheithauer presented with Cushing's disease and at least focally expressed adrenocorticotrophic hormone on immunohistochemistry. However, nonfunctioning tumors are also seen, albeit rarely. These are known to be associated with DICER 1 mutations and have a poor prognosis. Hence, morphologic recognition in the right clinical context and excluding other differential diagnoses in infants help make the correct diagnosis.

Granulomatous diseases of the central nervous system: Approach to diagnosis

Diagnosis of central nervous system (CNS) granulomas is challenging. The etiology may be infectious or non-infectious. The infectious causes are due to mycobacteria, fungi, parasites and rarely bacteria. The non-infectious causes include autoimmune diseases, diseases of uncertain etiology like sarcoidosis, those associated with neoplasms and reparative processes. Histologic evaluation of type of granuloma as necrotizing, non-necrotizing, fibrotic/calcific or foreign-body type, site of CNS involvement (leptomeninges/dura, brain/spinal cord) and identification of etiologic agent on histochemistry/culture/molecular methods resolves the diagnosis in a many a patient. Correlation with clinical and imaging features, risk factors and route of spread, geographical location and travel history are important. However, diagnosis may remain unresolved despite the application of all available techniques, highlighting the need for better diagnostic techniques.

Juvenile idiopathic inflammatory myopathies: A clinicopathological study with emphasis on muscle histology

Background: Juvenile idiopathic inflammatory myopathies (JIIM) are rare and heterogeneous. Subtype identification is important for treatment. Materials and Methods: Patients below 18 years diagnosed as idiopathic inflammatory myopathy (IIM) according to the Bohan and Peter criteria between January 2010 and May 2015 were evaluated with muscle biopsy in the four domains: muscle fiber, inflammation, connective tissue, and vascular, with basic panel of histochemical stains as per recommendations of the European Neuromuscular center (ENMC) workshop 2015. Immunohistochemistry with CD 31 was done to assess capillary density. Results: JIIM constituted 15.25% of IIM with juvenile dermatomyositis (JDM) being the most common subgroup (24/27) followed by juvenile overlap myositis (JOM) (3/27) in association with systemic lupus erythematosus (2) and systemic sclerosis (1). Muscle biopsy in JDM was characterized by perifascicular atrophy, necrosis, degeneration, and regeneration in all and the other features included perivascular inflammation (21), lymphoid aggregates (2), mitochondrial abnormalities (9), sarcoplasmic vacuoles (6), capillary dropout (5), capillary dilatation (6), and perimysial fibrosis (14). JOM was characterized by auto-antibodies and perivascular inflammation. Conclusion: JIIMs were rare and JDM was the most common subtype. Muscle biopsy evaluation as per ENMC criteria characterized the subgroups.

Primary central nervous system lymphomas: Indian experience, and review of literature.

Primary central nervous system lymphomas (PCNSLs) are a rare form of non-Hodgkin's lymphoma which arise within and remain confined primarily to the central nervous system (CNS). They generally account for 1-2% of all primary brain tumors and are reported to be on the rise due to the Acquired Immune Deficiency Syndrome (AIDS) epidemic. AIMS AND OBJECTIVES: To study the clinicopathological and immunophenotypic characteristics of PCNSLs and look for any differences in PCNSLs reported in India from those in other countries. MATERIALS AND METHODS: All cases of PCNSLs between January 1998 and December 2006 were reviewed. Presence of lymphadenopathy, organomegaly and bone marrow study was done to exclude the possibility of secondary involvement by lymphoma. The diagnosis was confirmed by histopathology with Hematoxylin and Eosin and reticulin stains. Immunohistochemistry (IHC) with leucocyte common antigen (LCA), CD 20 and CD 3 was performed on available blocks. The immune status was evaluated by clinical examination and human immunodeficiency virus (HIV) serology (since 1996). RESULTS: In a 19-year study period, there were 56 patients of PCNSLs, accounting for 1.07% of all intracranial neoplasms. The patients ranged from 10-75 years of age with a median age of 42 years. Barring one patient who was HIV positive, all the others were immunocompetent. All cases were diffuse large cell lymphomas on histopathology. IHC with LCA and CD 20 revealed positivity in 100% and 86.4% cases respectively. There was a single case of CD 3 positive T-cell lymphoma. In the present study, PCNSLs occurred in young immunocompetent patients and majority were diffuse large B cell lymphomas.