Nonmeningothelial Dural-Based Lesions: A Histopathological Analysis.

Introduction We report 30 cases of nonmeningothelial dural-based lesions encountered during a 3-year study period. Materials and Methods We retrospectively reviewed pathology records of patients operated for extra-axial, dural-based lesions during the years 2016 to 2018 and included nonmeningothelial lesions as a part of this study. Results Among the 3,243 neurosurgical specimens for histopathologic examination, only 30 (0.93%) were "nonmeningothelial dural-based lesions." Six (20%) patients were in the pediatric age group. Pathologic assessment identified 13 cases of solitary fibrous tumor/hemangiopericytoma (43.3%) and 7 cases of Ewing's sarcoma/primitive neuroectodermal tumor (23.3%). Two cases (6.7%) were of metastasis. Other lesions included a single case each of non-Hodgkin's lymphoma, undifferentiated sarcoma, solitary plasmacytoma, and granulocytic sarcoma. Nonneoplastic lesions included two cases each of Rosai-Dorfman disease and nonspecific inflammatory lesions. Conclusion Nonmeningothelial dural-based lesions being rare, thorough examination of morphological features is a must by the pathologist, to arrive at the accurate diagnosis. Ancillary tests, if required, should be employed in the context of the morphologic picture.

An Autopsy Study of Cerebrovascular Atherosclerosis in the Elderly.

Background: Stroke is an important cause of mortality with intracranial atherosclerosis as an important risk factor. Geographical variation in the pattern of atherosclerosis is well documented with various studies in stroke patients showing that African Americans and Japanese people tend to have intracranial vascular occlusion, whereas Caucasians more often have extracranial atherosclerotic lesions. Methods: This is a prospective study of 50 cases of Indian elderly patients over 60 years of age where we have studied the CNS vasculature in detail including intracranial atherosclerosis with regards to its incidence, severity, distribution, plaque composition and associated risk factors. We compared the atherosclerotic pathology in the intracranial vessels and the extracranial vessels including the carotids. Results: Out of 50 cases 31 showed intracranial atherosclerosis. Anterior circulation was more commonly affected. A total of 87 of the intracranial arteries showed atherosclerotic plaques, most common nature of the plaques being fibrofatty. Majority of the intracranial vessels showed mild stenosis and multiple vessels were involved in 15 cases while single vessel involvement was seen in 16 cases with the middle cerebral artery being the most common single vessel involvement. Infarcts were seen in 7 cases and all these cases had history of hypertension. Cerebral atrophy was seen in 28 cases. All cases showing frontoparietal and generalized atrophy had carotid artery stenosis. Of the 100 carotid arteries studied (2 per case) 59 showed atherosclerosis. Majority of the carotid arteries showed mild degree of atherosclerosis and the content was predominantly fatty. Conclusion: This study concludes that the pattern of atherosclerosis is different in the Indian population as compared to the western literature. Intracranial atherosclerosis is more common in Indian population with the anterior portion of circle of Willis being more commonly affected.

Eosinophilic meningitis due to A. Cantonensis revealed at autopsy.

Parasitic infection of the central nervous system could be fatal, and its incidence is rising due to increasing worldwide travel. Amongst the various nematodes, Angiostrongylus contonensis is the commonest and causes eosinophilic meningitis. It is a zoonotic disease produced due to the ingestion of raw or undercooked snails or slugs. Most cases of angiostrongyliasis are mild and self-limiting, but death can occur in severe cases lacking timely and proper treatment. Very few autopsy cases of A. cantonensis are reported. We present the case of a 32-year-old mentally challenged orphan male with eosinophilic meningitis at autopsy.

Intravascular papillary endothelial hyperplasia of the cavernous sinus-A rare occurrence.

Intravascular papillary endothelial hyperplasia (IPEH) is a benign, reactive proliferation of endothelial cells within areas of thrombus. It most commonly occurs in the skin and subcutaneous tissue, with less than 40 cases reported in intracranial location. Ours is the first case report from India of IPEH in the cavernous sinus. A 45-year-old male presented with headache and decreased visual acuity. Magnetic resonance imaging (MRI) revealed a well-defined, homogeneously contrast-enhancing mass in the cavernous sinus. Postoperatively, examination of tissue showed organizing thrombus within the vessel wall along with delicate, acellular, pseudopapillary cores. The fibrin-rich connective tissue of these showed blue staining with Masson's trichrome stain. These were lined by a single layer of endothelial cells without evidence of atypia; no nuclear pleomorphism, hyperchromasia, atypical mitosis, or areas of necrosis were seen. Hence, it was diagnosed to be IPEH. Follow-up MRI revealed no residual disease and the patient is disease-free at 8 months. Recognition of this entity by pathologic examination is important to rule out angiosarcoma. Gross total resection is curative. Residual lesions have the potential for recurrence, requiring adjuvant therapy.

Melanoma of the central nervous system: A report of three cases.

Melanomas within the Central Nervous System (CNS) are most commonly metastatic lesions, with primary melanomas comprising only 0.05-0.07% of all brain tumors. We report three cases of primary CNS melanoma. The patients were young adults. There were two females and one male. On preoperative investigations, two cases were misdiagnosed to be angiomas on Magnetic Resonance Imaging (MRI). The melanotic nature of the lesion was an intraoperative observation. Pathologic examination showed features of malignancy with invasion of tumor cells into the brain parenchyma. In two patients, presence of systemic lesions were ruled out after surgery by whole-body Positron Emission Tomography (PET) scan. These patients were subject to adjuvant radiotherapy, while one patient succumbed immediately post-surgery. Primary CNS melanomas are rare with no defined treatment protocols. Histopathology diagnosis is crucial to rule out pigmented mimics.

Coexistent intracerebral metastatic melanoma and meningioma.

Coexistence of multifocal neural crest tumors, namely meningioma, melanoma, and nerve sheath tumors, is termed as neurocristopathy. Neurofibromatosis is the commonest form of neurocristopathy. We report a rare case of frontal lobe metastatic melanoma coexistent with a parietal lobe meningioma, in the absence of any stigmata of neurofibromatosis.

Omental sclerosing extramedullary hematopoietic tumors in Janus kinase-2 negative myelofibrosis: caveat at frozen section.

Sclerosing extramedullary hematopoietic tumors (SEMHTs) are associated with chronic myeloproliferative neoplasms. These extremely rare mass lesions were first described in kidney and peritoneum. On histopathology, they are characterized by sclerosis, entrapped fat, atypical megakaryocytes with myeloid and erythroid elements. Only approximately ten cases have been subsequently reported in orbit, lacrimal system, liver, omentum, and skin. The authors present a case of SEMHTs as incidentally detected omental nodules, while the patient was undergoing splenectomy for Janus kinase-2 negative myelofibrosis. The authors postulate their origin in omentum-associated lymphoid tissue; and highlight the diagnostic dilemma presented by SEMHTs at frozen section.

Primary yolk sac tumor of the cerebellar vermis: a case report.

Extragonadal germ cell tumors are rare and comprise 2-5% of all germ cell tumors. Seminoma/dysgerminoma, teratoma, yolk sac tumor (YST) and mixed germ cell tumors are few of the extragonadal germ cell tumors arising within the brain. Of these, primary pure YSTs arising in the brain are extremely rare and arise in the pineal (62%) and suprasellar (31%) regions. Primary YST occurring in the cerebellum is exceedingly rare, associated with a very poor prognosis and has been reported in less than 10 cases in literature. We herein report a case of primary pure yolk sac tumor in the cerebellar vermis in a 2-year-old child.

Profiles of Alzheimer's disease-related pathology in an aging urban population sample in India.

Systematic studies on Alzheimer's disease (AD)-related pathology that complement clinical and epidemiological data on dementia from low and middle income countries are rare. We report the first large study on AD-related pathology in autopsy service-derived brains from an urban center in India, a low/middle income country, and compare findings with a similar sample from New York. Amyloid-ß plaques and neurofibrillary tangles were assessed in 91 brain specimens derived from hospital autopsy cases from Mumbai, India (age 60+ years; mean age 71.1 years, ± 8.3 SD; range 60-107 years) and compared with identically examined age-matched sample obtained in New York. These cases had no known clinical history of dementia. Our study showed that in comparison with the New York sample, the mean brain weight of the Mumbai sample was lower (p = 0.013) and mean diffuse plaque density was higher (p = 0.019), while differences in mean density and counts of neurofibrillary tangles and neuritic plaques were not statistically significant (p > 0.05). Our findings indicate that the burden of AD-related pathology was approximately equivalent in Mumbai and New York samples, which is at variance with expected lower AD-related lesion burden based on the clinical/epidemiological studies suggesting lower prevalence of AD in India.

Multiple focal nodular hyperplasia, an incidental finding on autopsy.

Focal nodular hyperplasia (FNH) is a benign condition of the liver often discovered incidentally on radiological investigation. Although FNH is a well-described lesion in the literature considerable diagnostic problems regarding this entity still remains. We report a case of multiple FNH in a 23-year-old male patient detected as an incidental finding in autopsy. On gross examination FNH was not suspected because of the multiple lesions and the lack of central scar which is characteristically described in FNH. The diagnosis was established on histopathology after examination of multiple sections of the lesions.

Colloid cyst of the velum interpositum: a common lesion at an uncommon site.

BACKGROUND: Colloid cysts are typically located in the region of the anterior third ventricle in the proximity of foramen of Monro. Although 'endodermal cyst' has been identified in several regions of the brain, location of characteristic colloid cyst entirely within the confines of velum interpositum and outside the ventricles has not been reported earlier. CASE DESCRIPTION: We report a unique case of colloid cyst located in the region of velum interpositum in a 33-year-old patient with headache and seizures. Such a location of the colloid cyst has not been identified earlier in the literature. The literature on pathogenesis of colloid cysts in general is briefly reviewed. CONCLUSIONS: Colloid cyst located in the velum interpositum is reported. Such a location gives additional information on the pathogenesis of these lesions.

Macrophage migration inhibitory factor (MIF) is critical for the host resistance against Toxoplasma gondii.

Macrophage migration inhibitory factor (MIF) exerts either a protective or a deleterious role in the immune response to different pathogens. We analyzed herein the role of MIF in the host control of toxoplasmosis using MIF(-/-) mice backcrossed to either the BALB/c or the C57BL/6 genetic backgrounds. Both, wild-type (WT) BALB/c and MIF(-/-) BALB/c mice were susceptible to infection with highly virulent RH as well as moderately virulent ME49 strains of T. gondii. MIF(-/-) mice, however, showed greater liver damage and more brain cysts, produced less proinflammatory cytokines, and succumbed significantly faster than WT mice. Bone marrow-derived dendritic cells (BMDCs) from MIF(-/-) mice produced less interleukin-1beta, interleukin-12, and tumor necrosis factor-alpha than WT BMDCs after stimulation with soluble Toxoplasma antigen (STAg). Similar observations were made in CD11c(+) low-density cells isolated from the spleens of MIF(-/-) mice challenged with STAg. MIF(-/-) C57BL/6 mice succumbed to ME49 infection faster than their WT counterparts. C57BL/6 mice that succumbed to infection with the ME49 strain produced less MIF than resistant BALB/c mice similarly infected. Interestingly, an analysis of brains from patients with cerebral toxoplasmosis showed low levels of MIF expression. Together, these findings demonstrate that MIF plays a critical role in mediating host resistance against T. gondii.

Mature teratoma arising from the middle cranial fossa.

A 25-year-old man presented with a sudden spurt in size of a bony swelling around the external ear, which was present since birth. This was associated with a painful swelling of the right half of the face and pain, redness, and decreased vision in the right eye. Neurologic examination showed decreased visual acuity in the right eye and paresis of the fifth, seventh, and eighth cranial nerves. Neuroimaging showed an extra-axial, partly cystic tumor of mixed density, located entirely within the middle cranial fossa scalloping the temporal bone and extending into the right infratemporal fossa and the right middle ear and impinging on the ipsilateral cavernous sinus. The right temporal lobe was elevated and compressed. Histopathologic examination confirmed a mature teratoma.