Atypical Teratoid/ Rhabdoid Tumor of Brain: a Clinicopathologic Study of Eleven Patients and Review of Literature

Background: Atypical teratoid/ rhabdoid tumor (AT/RT) is a rare aggressive embryonal central nervous system (CNS) tumor of infancy and early childhood. Majority of the cases arise in the posterior fossa, and remaining in the cerebrum. Aims: To analyze the clinicopathologic features of AT/RT on a cohort of cases. Materials and methods: All reported cases of AT/RT at the Department of Pathology and Laboratory Medicine, Aga Khan University Hospital (AKUH) from 2007 to 2016 were reviewed for clinical and pathological features. Immunohistochemical stain for INI-1 was performed in all 11 cases. Follow up was obtained. Results: A total of 11 cases were identified. Seven patients were males and 4 were females. The ages ranged from 1 month to 48 months (mean 26.6 months). Six tumors were located in the cerebrum and 3 in the posterior fossa. Exact Location was not known in 2 cases. Histologically, rhabdoid cells were present in sheets in variable proportions in five cases, Medulloblastoma and PNET like areas were seen in 2 cases each. Immunohistochemical stains EMA (10/10), vimentin (7/7), CKAE1/AE3 (8/9), and CD99 (3/4), GFAP (6/10), ASMA (3/4) and synaptophysin (3/4) were positive in varying proportions while desmin was negative in all 6 cases in which it was performed. All 11 tumors lacked immunoreactivity for INI-1 protein. Four patients died of disease with a follow up ranging from 5 to 24 months. Conclusions: AT/RT is a rare highly aggressive embryonal tumor of CNS. A male predominance was noted in our series. We report the first and largest series from Pakistan.

Isolated adult hypoganglionosis presenting as sigmoid volvulus: a case report.

INTRODUCTION: Isolated hypoganglionosis is a rare cause of intestinal innervation defects. It is characterized by sparse and small myenteric ganglia, absent or low acetylcholinesterase activity in the lamina propria and hypertrophy of the muscularis mucosae, principally in the region of the colon and rectum. It accounts for 5% of all intestinal neuronal malformations. To the best of our knowledge, only 92 cases of isolated hypoganglionosis were reported from 1978 to 2009. Isolated hypoganglionosis usually manifests as enterocolitis or poor bowel function, and is diagnosed in infancy or childhood. We report the first case of isolated hypoganglionosis presenting with sigmoid volvulus in a 34-year-old woman. CASE PRESENTATION: A 34-year-old Asian woman had progressively increasing abdominal pain and had not passed stool or flatus for two days. A physical examination revealed a distended abdomen with sluggish gut sounds. A computerized tomography (CT) scan demonstrated gross dilatation of the sigmoid colon (maximal diameter 14.3 cm) suggestive of sigmoid volvulus. During emergency laparotomy, sigmoidectomy with a side-to-side colorectal anastomosis was performed. Histopathology of the resected specimen showed occasional ganglion cells and hypertrophied nerve bundles in the muscle layers, suggesting hypoganglionosis. Colonoscopy was performed, and multiple full-thickness biopsies were taken that showed hypoganglionosis of the entire large bowel. Our patient underwent total colectomy with an ileorectal anastomosis. Subsequently our patient reported a dramatic improvement in her bowel function. CONCLUSIONS: Isolated hypoganglionosis is a rare cause of intestinal dysganglionosis and cannot be differentiated from Hirschsprung's disease based on clinical presentation. This case report describes an atypical presentation of the disease. A definitive diagnosis requires histopathological analysis of full-thickness intestinal biopsies. Treatment should be tailored to the extent of hypoganglionosis.

Rhinocladiella mackenziei as an emerging cause of cerebral phaeohyphomycosis in Pakistan: a case series.

Six cases of Rhinocladiella mackenziei cerebral phaeohyphomycosis are being reported for the first time in Pakistan. Identification was confirmed by DNA sequencing (isolates and fixed tissue). Diabetes, head trauma, immunosuppressive treatment, and postpartum state were present in 4 cases. Two survivals and 3 fatalities occurred, with 1 patient lost to follow-up.

Diffuse ganglioneuromatosis of intestine in a 15-year-old girl.

The authors present the case of a 15-year-old girl with diffuse ganglioneuromatosis, principally involving the caecum. This is a rare condition and usually associated with multiple endocrine neoplasm IIb and neurofibromatosis type I. In our case, the myentric nerve plexus was exclusively involved. The patient presented with episodes of vomiting and weight loss. So far, to our knowledge no other manifestations of the above mentioned genetic conditions have become apparent in this patient.

Spindle epithelial tumor with thymus-like differentiation of thyroid gland: report of two cases with follow-up.

Spindle epithelial tumor with thymus-like differentiation (SETTLE) is a rare malignant thyroid tumor showing thymic or related branchial pouch differentiation. The tumors are composed predominantly of spindle cells along with focal epithelial component and ductular formations. SETTLE occurs in young patients, with indolent growth and a tendency to develop delayed blood-borne metastases. We herein report two cases of SETTLE with a follow-up period of 64 months and 30 months, respectively.

Spectrum of malignancy in mixed tumors of salivary gland: a morphological and immunohistochemical review of 23 cases.

Malignancy arising in mixed tumors of the salivary gland is a distinct entity that can occur sporadically or in association with a background of pleomorphic adenoma. Carcinoma arising with a background of pleomorphic adenoma is well documented. However, there are rare occurrences of aggressive de novo carcinosarcomas of the parotid that have been reported. Various cell lineages such as the epithelial glandular cells and the stromal spindle cells are involved. We report 23 cases of tumors of the salivary gland comprising 18 cases of carcinoma ex pleomorphic adenoma, four cases of carcinosarcoma of the parotid and one case of benign metastasizing pleomorphic adenoma. The occurrence of various malignancies suggests that this phenomenon is not very uncommon and should be looked for when reporting a mixed tumor.

Fibromatous periorchitis.

We report a case of diffuse fibrous pseudotumour/fibromatous periorchitis, in a 43 year old male, that completely encased the right testis and was adjacent to a hydrocoele cavity. Although fibrous pseudotumours of this region are uncommon, they are reported to be the second most common benign paratesticular lesion after adenomatoid tumours. These comprise approximately 6 percent of paratesticular lesions, and are accepted as reactive lesions secondary to trauma, hydrocoele, infections or inflammation. Fibrous pseudotumours have a peak incidence in the third decade of life but can occur at any age. Clinically these lesions mimic malignancy resulting in the treatment by radical orchidectomy. Fibrous pseudotumours should be considered in differential diagnosis when one encounters a predominantly fibrocollagenous lesion.