Asha Shenoy

Distinctive microRNA signature of medulloblastomas associated with the WNT signaling pathway

AIM Medulloblastoma is a malignant brain tumor that occurs predominantly in children. Current risk stratification based on clinical parameters is inadequate for accurate prognostication. MicroRNA expression is known to be deregulated in various cancers and has been found to be useful in predicting tumor behavior. In order to get a better understanding of medulloblastoma biology, miRNA profiling of medulloblastomas was carried out in parallel with expression profiling of protein-coding genes. MATERIALS AND METHODS miRNA profiling of medulloblastomas was carried out using Taqman Low Density Array v 1.0 having 365 human microRNAs. In parallel, genome-wide expression profiling of protein-coding genes was carried out using Affymetrix gene 1.0 ST arrays. RESULTS Both the profiling studies identified four molecular subtypes of medulloblastomas. Expression levels of select protein-coding genes and miRNAs could classify an independent set of medulloblastomas. Twelve of 31 medulloblastomas were found to overexpress genes belonging to the canonical WNT signaling pathway and carry a mutation in CTNNB1 gene. A number of miRNAs like miR-193a, miR-224/miR-452 cluster, miR-182/miR-183/miR-96 cluster, and miR-148a having potential tumor/metastasis suppressive activity were found to be overexpressed in the WNT signaling associated medulloblastomas. Exogenous expression of miR-193a and miR-224, two miRNAs that have the highest WNT pathway specific upregulation, was found to inhibit proliferation, increase radiation sensitivity and reduce anchorage-independent growth of medulloblastoma cells. CONCLUSION Expression level of tumor/metastasis suppressive miRNAs in the WNT signaling associated medulloblastomas is likely to determine their response to treatment, and thus, these miRNAs would be important biomarkers for risk stratification within the WNT signaling associated medulloblastomas.

Ischaemic complications after surgical resection of intracranial aspergilloma

A 32-year-old male presented with a paranasal sinus Aspergillus fungal infection. The nasal infection was cleared by endoscopic sinus surgery and the patient was treated with antifungal agents. The patient was otherwise healthy with no evidence of immunosuppresion. Five months later, the patient had to undergo excision of the left frontal intracranial infection for symptoms of raised intracranial pressure and seizures. Within 48hours of surgery, the patient developed basilar artery thrombosis with infarction of the cerebellum and midbrain. The patient succumbed to this vascular catastrophe, which developed at a site distal to that from surgery. The pathophysiology of ischaemic complications after surgical resection of intracranial aspergilloma is discussed.

Three distinct co-existent primary brain tumors in a patient.

A rare case of simultaneous occurrence of three entirely distinct intracranial tumors is described. A 55-year-old male with no evidence of phacomatoses or history of radiation therapy presented with complaints of increased drowsiness, headaches, and dysarthria. Investigations revealed an olfactory groove meningioma, a glioblastoma multiforme in the left medial temporal lobe, and a diffuse glioma in the brain stem. Occurrence of multiple varieties of tumors at the same time is extremely rare. Theories that explain their occurrences including the role of common carcinogens, autocrine growth factors, and tumor suppressor genes are discussed.

Hydatid disease of the spine: A rare case

Hydatid disease or hydatidosis is the most widespread zoonosis caused by Echinococcus granulosus. Liver and lungs are the most common sites. Bone involvement is rare and reported in 0.5%–4% with spinal involvement reported in 50% of these cases. We present a case of spinal hydatidosis in a 35-year-old male presenting with lower extremity weakness and numbness. Magnetic resonance imaging (MRI) of the spine showed multiple cystic lesions at the T9–T11 level with involvement of the paraspinal muscles. The lesion was seen intraspinal, intradural, intramedullary, and epidural. Radiological impression was aneurysmal bone cyst. The patient underwent laminectomy, and the excised cysts showed characteristic features of hydatid cyst (HC) on histopathology. The patient was started on antihelminthic therapy postoperatively. MRI is a diagnostic modality for HC, but the unusual location and absence of characteristic features can cause diagnostic difficulty. A high index of suspicion should be kept in patients residing in endemic areas and presenting with unusual cystic lesion of spine.

Eccrine Spiradenoma of the Vulva

A 23-year-old woman presented with a gradually increasing swelling on the left labia majora since 2 years. The lesion measured approximately 1.5 9 1 cm and was soft, well circumscribed and slightly painful and tender. Clinical impression was lipoma and was excised. Histopathologic examination showed well-demarcated multiple basophilic tumour nodules, comprising of lobules of round–oval cells arranged in acinar, trabecular and diffuse pattern. The stroma surrounding these lobules was hyalinised. Two types of distinctive cells were observed: the periphery showed small, dark, basaloid cells, with hyperchromatic nuclei, while cells with large nucleus and pale cytoplasm were located in the centre and towards the lumen (Fig. 1a, b). Mild to moderate lymphocytic infiltrate and many blood vessels were also observed. The histomorphology was characteristics of an eccrine spiradenoma. The vulvar region contains dense apocrine glands, anogenital mammary-like glands, eccrine glands and folliculosebaceous units [1]. Benign and malignant lesions derived from these adnexal structures are found in the vulva but are rare [1]. Baker et al. [1] in his retrospective study of 32 years identified 189 vulvar adnexal lesions. Most of these lesions were benign (70%), with hidradenoma papilliferum being the most common, followed by syringoma and various types of cysts [1]. Other lesions included were rare cases of tubular adenoma, poroma, spiradenoma, hidradenoma, cylindroma, sebaceoma and trichoepithelioma [1]. He identified only two cases of spiradenoma, but details were not documented. Eccrine spiradenoma (ES) is an uncommon benign adnexal neoplasm originating from the eccrine glands and has characteristic clinical and histomorphological features [2]. It usually occurs in the 2nd–4th decade of life as a painful solitary well-circumscribed dermal nodule with pink or blue hue [2]. Rarely, it may present as multiple lesions in a linear zosteriform pattern [2]. The lesion is one of the classically painful cutaneous lesions, others being angiolipoma, endometrioma, dermatofibroma, neuroma, neurilemmoma, glomus and leiomyoma [3]. The common sites for ES are head and neck, upper trunk or extremities [4]. There are sporadic case reports of unusual sites which includes breast, ear, nail fold and face [4]. Vulva is a very rare site and not reported. Histologically, ES is a well-circumscribed dermal tumour showing multiple basophilic nodules surrounded by hyalinised stroma, resembling lymph node when observed under a low power microscope. The pathognomonic features are the presence of two-cell populations: a central cluster of pale large cells surrounded by small, dark, basaloid cells, with hyperchromatic nuclei [2]. In certain cases, lymphocyte infiltrate and significant vascular proliferation can be observed. Dermal cylindroma is a close differential diagnosis of ES, but its commonest site of occurrence is scalp and displays ‘‘jigsaw puzzle’’ pattern of tumour cells with prominent hyaline matrix on histology [2]. Other differentials include trichoepithelioma and glomus tumour. ES can be syndromic (Brooke–Spiegler syndrome) and also has a potential for malignant transformation. Malignant spiradenoma generally arise in a long-standing benign ES [5]. Thus, early and correct diagnosis is critical. Occurrence at rare sites can cause diagnostic difficulties, but knowledge of characteristic morphology will navigate towards the right diagnosis. & Mona Agnihotri mona.agnihotri2@gmail.com

Ependymomas: A clinicopathologic study

Introduction: Ependymomas are glial neoplasms that account for 4-8% of primary CNS neoplasms. Considerable controversy exists with regards to their prognosis and management, owing to their rarity and heterogeneity. Objectives: To study the clinical and pathologic features of ependymomas and evaluate their important prognostic variables. Materials and Methods: A 10 year retrospective study was carried out. The age, sex, location, clinical presentation, radiologic findings, microscopy, type of excision and follow up findings were studied. Results: 168 ependymomas were identified in a total of 6628 biopsies((2.53%). Majority were seen in the second decade (42/168), M:F ratio was 2:1. 15.48% (26 cases) occurred in the supratentorial compartment, 36.92% (62 cases) infratentorially, and 47.61% (80 cases) in the spinal cord. 90% of the intracranial tumors presented with features of raised ICT while patients with spinal tumors had focal motor deficits. There were 146 classic grade II ependymomas(78.5%), most common location being the posterior fossa, 36 myxopapillary ependymomas(17.8%), all seen in the lumbosacral region and 6 anaplastic ependymomas(3.57%). Anaplastic ependymomas were seen supratentorially in children and young adults while the peak of myxopapillary tumours was in third and fourth decades. 105 patients underwent gross or near total excision while in 16 it was partial or subtotal. Follow up was available in 73 patients. 9 patients died in the immediate post – operative period. Follow up for the rest varied from 3 months to 9 years. Anaplastic ependymomas were associated with a poorer prognosis. In supratentorial and lumbosacral tumours there was no difference in survival between gross total and subtotal excision while in adult infratentorial grade II ependymomas and cervical ependymomas, gross total excision had a better three year survival. Conclusions: The prognosis of ependymomas is multifactorial and depends on histologic type and extent of surgical removal. Access this article online Quick Response Code: Website: www.innovativepublication.com DOI: 10.5958/2394-6792.2016.00088.0 Introduction Ependymomas are central nervous system (CNS) tumours arising from ependymal lining of the ventricles and central canal of the spinal cord. In children, they are the third most common CNS neoplasms after astrocytomas and medulloblastomas and arise mostly infratentorially. In adults, their overall frequency is less as compared to other CNS neoplasms. They arise mostly in spinal cord, where they are the most common intramedullary spinal neoplasms. Though most ependymomas are WHO grade I & II neoplasms and the anaplastic variety (WHO Grade III) is rare; their prognosis depends on the location, age and completeness of surgical removal. To clarify the clinical, pathological & treatment characteristics that determine the prognosis and therapeutic recommendations, there is a need to study these tumours. Aim of the Study This retrospective analysis was carried out to determine incidence of ependymomas at our institute, study the various histological grades and subtypes of ependymomas with reference to age group, gender, location and to correlate the prognosis with the patient’s age, location, histological grade and subtype and type of surgical removal. Material and Methods This is a ten years retrospective study carried out at a tertiary care hospital. The tissues were fixed in 10% formalin and submitted for routine histopathological processing after adequate fixation. Paraffin sections were cut at 4 to 6 microns and were stained with routine Hematoxylin and Eosin (H&E) stain. Special stains such as PTAH, Alcian blue etc. were performed wherever necessary. Proliferative index (MiB1) was done in selected cases. The clinical, radiological, therapeutic data and follow up information was obtained from the patient’s original case records. The anatomic location of the tumor was based on the radiological imaging and operative findings. The tumours were grouped into 3 large categories: a) Supratentorial, b) Infratentorial and c) Spinal. The supratentorial tumors included the tumors arising from lateral and third ventricles, paraventricular tissues as well as those arising from cortex and other rare supratentorial locations. The infratentorial tumors were divided as those arising from cerebellum and those arising from other infratentorial structures. The spinal tumors were divided into divided into 2 groups. The first group includes the tumors arising from cervical and thoracic part of spinal cord and second Asha Sharad Shenoy et al. Ependymomas: A clinicopathologic study Indian Journal of Pathology and Oncology, July-September 2016;3(3);470-478 471 group of lumbar and cauda equina tumors. These groups were made because of prognostic implications of the location of the tumor on the patient survival. The ependymomas were analyzed taking into consideration various parameters like age, gender, location, clinical features, radiological findings, type of surgery, histological features, grading and post-operative survival. They were assigned grade according to the WHO classification of CNS tumors, 4th edition, 2007. The assessment of surgery was done based upon the completeness of the therapeutic removal. The surgery was graded as ‘gross total’ when more than 90% of the tumor mass was removed, ‘subtotal’ when 70-80% and ‘partial’ when more than 50% of tumor removed. The completeness of the surgery was judged by the postoperative MRI scan. Results A total of 6628 CNS tumors were received in the Neuropathology laboratory during the study period. There were 168 Ependymomas, accounting for 2.53% of CNS tumors. The youngest patient was a 2 month old child while the oldest patient was 63 years old. Majority were seen in the second decade (42/168), 82 cases out of 168 occurred before 20 years of age, with incidence of 48.8%. After the 3rd decade, the incidence of ependymoma gradually fell. Table 1 depicts locations of the tumor. 47.61% of the cases were spinal in location. The overall male to female ratio was 2:1 while in the spinal cord, supra and infratentorial locations it was 3.4:1, 1.3:1 and 1.5:1 respectively. Table 2 shows the clinical features of the intracranial and spinal tumours. Headache, vomiting, focal neurologic deficits, backache, imbalance and bowel/bladder complaints were the common symptoms, depending on site. The various histologic types of Ependymomas and their sites are shown in Table 3. Myxopapillary, Classic ependymoma and its variants (cellular, tanycytic, papillary) as well as anaplastic ependymomas were seen.(Fig. 1A-F). There were 124 classic grade II ependymomas, nearly half of which were infratentorial in location. Both the tanycytic ependymomas were cervicothoracic and all Myxopapillary ependymomas were lumbosacral in location. Correlating the grade with age, as seen in Table 4, grade III tumours were seen in the first two decades of life, while Myxopapillary ependymoma (grade 1) was most common in the 3rd and 4th decades. Anapaestic ependymomas were more common in children. A pre-operative MRI diagnosis was given in 131/168 cases (Table 5). Supratentorial ependymomas were very difficult to diagnose on MRI. They were mistaken for astrocytomas/ oligodendroglioma or just labeled as gliomas. Infratentorial ependymomas were at times diagnosed as medulloblastomas radiologically. Table 6 shows the microscopic features like cellularity, presence of pseudo rosettes and true rosettes, necrosis, mitotic activity, microvascular proliferation etc., seen in the various histologic grades. The grade I and II tumours including the variants showed a Mib1 proliferative index of less than 5% while the anaplastic ependymomas showed a MiB1 labelling index between 10 40%, with a mean of 25%. Table 7 shows the type of surgical excision performed. 105 patients underwent gross or near total excision while in 16 it was partial or subtotal. Follow up was available in 73 patients. Out of these 9 patients died in the immediate post-operative period and their postmortem was performed. Follow up for the rest varied from 3 months to 9 years. Tables 8 and 9 shows the follow up and survival of patients less than and older than 12 years respectively, with respect to grade, location and type of surgery. Anaplastic ependymomas were associated with a poorer prognosis, in the three cases where follow up was available two died post operatively while one died at 1 year. In supratentorial and lumbosacral tumours there was no difference in survival between gross total and subtotal excision while in adult infratentorial grade II ependymomas and cervical ependymomas, gross total excision had a better three year survival. Asha Sharad Shenoy et al. Ependymomas: A clinicopathologic study Indian Journal of Pathology and Oncology, July-September 2016;3(3);470-478 472 Table 1: Location of Ependymoma Location No. of cases % of total ependymomas I Supratentorial(total) 26 15.48 1. ventricular 2. frontal 3. temporal 4. parietal 5. occipital 6. thalamus& brain stem 2 10 2 6 2 4 1.19 5.95 1.19 3.57 1.19 2.38 II Infratentorial(total) 62 36.90 1. Cerebellum 2. CPA and other posterior fossa structures 55 7 32.73 4.16 III Spinal cord(total) 80 47.61 1. Cervico-thoracic 2. Lumbo-sacral 28 52 16.67 30.95 IV Rare locations 0 0 * The values represent both intra and extra axial tumors CPA= Cerebello-pontine angle Table 2: Clinical presentation Clinical features Supratentorial Infratentorial Spinal cord Total Cervico-thoracic Lumbo-sacral 1 Headache 21 52 2 0 75 2 Vomiting 13 47 0 0 60 3 Visual disturbances 7 7 0 0 14 4 Convulsions 2 4 0 0 6 5 FND motor 8 5 24 37 74 6 FND sensory 0 1 13 9 23 7 Altered sensorium 7 9 0 0 16 8 Cranial nerve invovlment 3 2 0 0 5 9 Imbalance 2 17 3 4 26 10 Cerebellar signs 2 11 0 0 13 11 Backache 0 3 34 37 12 Bowel& bladder complaints 2 0 5 23 28 13 Impotence 0 0 1 1 Asha Sharad Shenoy et al. Ependymomas: A clinicopathologic study Indian Journal