Computed tomography-guided frame-based stereotactic brain biopsy of non-enhancing lesions using indirect evidence of target selection, technical consideration, and early clinical experience.

Background: The objective was to study the effectiveness and diagnostic outcome of frame-based stereotactic brain biopsy (STB) done for contrast non-enhancing lesions using indirect evidence of target selection observed in a plain computed tomography (CT) scan of the head. Methods: Data of patients with contrast non-enhancing brain lesions who underwent STB are collected retrospectively from NIMHANS Bangalore, hospital neurosurgery database from January 2021 to March 2023. Those cases subjected to plain CT scans after fixing the stereotactic frame to the head were included in the study. A final histopathological report analysis of these cases was done to assess the diagnostic accuracy. Results: A total of 27 such cases were biopsied. The mean age of subjects was 44.04 ± 17.812 years. Most subjects were in the age group 31-40 years (29.6%). About 55.6% were male and 44.4% were female. The most common site of biopsy was the frontal lobe. The most common indirect evidence on CT was perilesional edema at 33.3% and periventricular location at 33.3%, followed by intralesional calcification at 11.1%. Our diagnostic accuracy was 92.59%. The asymptomatic hemorrhage rate was 2%, and an increase in perilesional edema was seen in 2% of cases. Conclusion: Indirect targeting is a safe and intuitive method for biopsy of contrast non-enhancing lesions. Due consideration is to be given to various findings visible in non-contrast CT scans of the head as indirect evidence of target selection while performing frame-based STB of contrast non-enhancing lesions. This method will also be helpful in resource-limited centers, especially in low-income countries.

Identification of a Novel Intronic Mutation in VMA21 Associated with a Classical Form of X-Linked Myopathy with Autophagy.

Introduction VMA21 -related myopathy is one of the rare forms of slowly progressive myopathy observed in males. Till now, there have been only a handful of reports, mainly from Europe and America, and two reports from India. Method Here, we describe a case of genetically confirmed VMA21 -associated myopathy with clinical, histopathological, and imaging features with a list of known VMA21 mutations. Results A 29-year-old man had the onset of symptoms at 18 years of age with features of proximal lower limb weakness. Muscle magnetic resonance imaging showed the preferential involvement of vasti and adductor magnus. A biopsy of the left quadriceps femoris showed features of autophagic vacuolar myopathy with vacuoles containing granular eosinophilic materials. In targeted next-generation sequencing, hemizygous mutation in the 3' splice site of intron 2 of the VMA21 gene (c.164-7 T > A) was identified and confirmed the diagnosis of X-linked myopathy with excessive autophagy. Conclusion This report expands the phenotypic and genotypic profile of VMA21 -related myopathy, with a yet unreported mutation in India.

Delineating the Spectrum of Pituitary Adenoma Based on the WHO 2017 Classification.

BACKGROUND: The WHO 2017 classification of endocrine tumors incorporates lineage-specific transcription factors (TF) and hormone expression for the classification of pituitary adenoma (PA). There is paucity of reports describing the spectrum of PA based on this classification. OBJECTIVE: The aim of this study was to delineate the spectrum of PA based on WHO 2017 classification of endocrine tumors. MATERIALS AND METHODS: PA diagnosed in the year 2018 were studied. H and E and hormonal immunohistochemistry (IHC) for GH, PRL, ACTH, TSH, FSH, LH, CK, T-Pit and MIB-1 were performed and the results were analyzed. RESULTS: The cohort included 88 cases. M: F ratio was 2:1. Clinically, 22 (25%) were functional and 66 (75%) were non-functional adenomas. Amongst the clinically functional adenomas, GH secreting adenomas were the commonest (68%). Majority (83%) of non-functional adenomas were hormone positive with gonadotroph adenomas being the commonest (72.7%). Eleven (12.5%) PA were clinically and hormonally silent. Three of these showed intense nuclear T-Pit positivity, classifying them under silent corticotroph adenoma. Lineage of the remaining eight adenomas remained undetermined, since, IHC for Pit-1 and SF-1 was not performed. The aggressive adenomas identified by IHC included sparsely granulated somatotroph adenoma, Crooke cell adenoma, silent corticotroph adenoma, densely granulated lactotroph adenoma in men and constituted 17% of the PA. Four (4/88) cases were clinically invasive. CONCLUSION: A large majority of PA including aggressive adenomas can be identified by IHC. Addition of T-Pit helped to identify silent corticotroph adenoma. Pit -1 and SF-1 TF would help identify plurihormonal Pit-1 PA and null cell adenomas.

Primary diffuse leptomeningeal primitive neuroectodermal tumor presenting as chronic meningitis.

Primary diffuse leptomeningeal primitive neuroectodermal tumor is a rare meningeal neoplasm which can masquerade as chronic meningitis. While the clinical presentation and radiological features may provide a clue to this condition, meningeal biopsy is essential to clinch the diagnosis. A high index of suspicion and a low threshold for re-evaluating cases of neuroinfection that do not respond to empirical therapy are essential in this scenario. We present the case of a nine year old boy who was initiated on antituberculous treatment for chronic meningitis with hydrocephalus. Meningeal biopsy revealed a primary diffuse leptomeningeal primitive neuroectodermal tumor.

Non-granulomatous inflammatory lesions of CNS: Approach to diagnosis.

Infections constitute an important and common category of diseases, particularly in less developed countries. Infections present with a broad spectrum of clinical and radiologic features dictated by the cell and tissue tropism and host response elicited, posing a considerable diagnostic challenge. Early diagnosis and treatment are crucial in preventing mortality and morbidity. Recourse is often made to biopsy for ascertaining the diagnosis, and hence the pathologist plays a vital role in patient management. Therefore, knowledge of the histopathologic changes is necessary to recognize the histological changes and guide the diagnostic workup and management. Each microbial agent elicits a distinctive pattern of inflammatory tissue response, which can serve as a clue to the etiological agent. Based on the causative organism, microbial, and host factors, the inflammatory response may be acute or chronic, necrotic or non-necrotic. The inflammation can be of varied patterns - lymphohistiocytic, granulomatous, inflammatory demyelinating, fibrosing, or showing minimal inflammation. The pattern of necrosis also differs based on the causative organism. Typically, pyogenic bacteria are associated with suppurative inflammation, tuberculosis with caseous granulomatous, and fungi with suppurative granulomatous inflammation. Viral infections are associated with lymphohistiocytic non-necrotizing inflammation and, based on cell tropism, can cause demyelination (e.g., JCV) and/or viral inclusions. Parasitic infections (protozoal or metazoal) display a broad spectrum of inflammatory changes that overlap with other types of infections. This review briefly describes pathological patterns and associated pathogens and provides an algorithmic approach based on pattern recognition that may be useful for the practicing pathologist.

Pathological Spectrum of Dura-Based Nonmeningothelial Lesions: 5 Years' Experience from a Tertiary Care Centre.

Introduction Nonmeningothelial lesions arising from the dura comprise a wide spectrum of pathologies ranging from neoplastic to infective etiologies. They have overlapping clinical and radiologic findings necessitating histopathological evaluation for the final diagnosis which in turn dictates management and prognosis. Therapeutic strategies are different for each of the lesion. There is scarcity of large case series detailing clinicopathological spectrum of dura-based nonmeningothelial lesions. Materials and Methods In this study, we analyzed the neuropathological spectrum of dura-based nonmeningothelial lesions diagnosed over a period of 5 years in our tertiary care center. Results There were 79 cases of dura-based nonmeningothelial lesions constituting 7.3% of all dura-based lesions (age range: 2-75 years; M:F = 2:3). Basal region was more frequently involved than the convexities. On histopathology, neoplastic lesions predominated (92.4%) and included in order of frequency solitary fibrous tumor/hemangiopericytoma (35.6%), gliomas (27.4%), metastasis (27.4%), mesenchymal tumors (4%), primitive neuroectodermal tumor (2.73%), and medulloblastoma (2.73%). Infective lesions were less frequent (7.6%), included fungal infections and Rosai-Dorfman disease. Conclusion Awareness of the spectrum of nonmeningothelial dural lesions is useful for pathologists as well as the treating surgeon.

Pilocytic astrocytoma with spontaneous malignant transformation with intracranial and skeletal dissemination: case report and review of the literature.

Pilocytic astrocytoma is a benign low-grade tumor with a favorable prognosis. We present a 47-year-old- lady with a posterior fossa pilocytic astrocytoma who underwent surgical decompression. She developed multiple early local recurrences Along with malignant transformation of the cranial lesion she developed skeletal dissemination within a very short time frame. There were no features or family history of neurofibromatosis 1. She did not receive radiotherapy or chemotherapy prior to the recurrences.