Post-chemotherapy neuroblastoma-like differentiation in ewing sarcoma of humerus: report of a rare case with review of literature

A 21-year patient initially presented with a fracture of the humerus following minor trauma. A bone scan and biopsy were done due to the suspicion of pathological fracture and the biopsy confirmed the diagnosis of Ewing Sarcoma [EWS]. Two months after initial presentation, chemotherapy was started and 5 cycles were given over a span of 6 months. Surgical resection of the tumor was then performed. The post-chemotherapy resection specimen, on histological examination, showed the presence of areas of neuroblastoma-like differentiation in otherwise morphologically classic EWS. Cytogenetic analysis by FISH revealed EWSR1 gene rearrangement. Four similar cases have been reported earlier in literature, all in females below 20 years of age. Our case is unique as it is the first case of post-chemotherapy neuroblastoma-like differentiation of EWS in a 21-year male

Olfactory neuroblastoma: a clinicopathological experience of a rare entity from Pakistan

Objectives: To present the clinicopathological experience of Olfactory Neuroblastoma [ONB] with emphasis on histopathological and immunohistochemical features

Methods: A descriptive cross-sectional study was done on 36 cases of ONB, selected by non-probability purposive sampling. Theses cases of ONB were retrieved and reviewed from surgical pathology database of Aga Khan University Hospital reported between January 1993 and March 2015

Results: Tumor size and age of presentation was wide in range without any distinct bimodal distribution. Nasal cavity was most common site along with involvement of paranasal sinuses. More than 50% cases had Kadish stage A. Microscopically, most cases were Grade-1 and majority showed partial or complete lobular architecture. Neurofibrillary matrix was observed in 2/3rd of cases. Among immunohistochemical markers, Neuron Specific Enolase was most frequently expressed. Unusual positive expression of Cytokeratin AE1/AE3 and Cytokeratin CAM5.2 was also seen focally in few cases

Conclusion: The ONB has great variability of histological and clinical presentation, and immunohistochemical markers are useful to differentiate from more common small round blue cell tumours of nasal cavity

Symptomatic surgically treated non-neoplastic cysts of the central nervous system: a clinicopathological study from Pakistan

To report clinicopathologic features of symptomatic surgically removed non-neoplastic cysts of the central nervous system [CNS]. Case series. The Aga Khan University Hospital, Karachi, from 2003 to 2012. All non-neoplastic CNS cysts reported during the study period were retrieved and reviewed. Age, gender, location, histologic type and clinical features were noted. A total of 124 cysts were diagnosed in the study period. These included 44 epidermoid cysts [mean age 30.5 +/- 13.8 years], 35 colloid cysts [mean age 31 +/- 13.2 years], 32 arachnoid cysts [mean age 24.8 +/- 20.2 years], 6 dermoid cysts, 3 enterogenous cysts and Rathke's cleft cysts each and 1 ependymal cyst. All cyst types mainly presented in young adults in both genders with signs and symptoms of a mass lesion. Non-neoplastic cyst mainly presented like a CNS mass lesion in young adults. Epidermoids were the most common type of these cysts in the present series followed by the colloid and the arachnoid cysts

Frequency and characteristics of breast lymphomas presenting to a tertiary care hospital Pakistan

To assess the relative frequency of [primary and secondary] mammary lymphomas presenting to a tertiary care hospital, Pakistan and its categorization according to WHO classification of lymphoid neoplasms. All NHLs [nodal and extra nodal] diagnosed in the section of histopathology during 1992-2004 were retrieved and reviewed. All patients [n=30] diagnosed with lymphomatous involvement of the breast were selected. Distinction between primary and secondary breast lymphomas was not made owing to lack of availability of clinical information. A total of 5637 breast malignancies were diagnosed in our department during the study period of 10 years and the total number of NHLs [Nodal and extra Nodal] was 2632. Thirty [n=30] patients accounting for 1.13% were diagnosed to have lymphomatous involvement of the breast. The Female to Male ratio was13.5:1; age range was 12-92 years with a median age of 43 years [Mean age 46.5 years and Standard deviation of age was 16.88 years]. The sites of the lesions were the right breast in 11 cases [37.93%], left breast in 9 cases [31.03%] and both breasts in 2 cases [6.89%], while the location of 8 masses [27.58%] was unknown. Immunohistochemical studies were negative for cytokeratins [MNF and Cam 5.2] in all cases. All cases of DLBCL expressed B cell lineage antigens and were positive for LCA and Pan B [CD20 and 79a]. We concluded that breast lymphomas represent 1.13% of all NHL and 0.5% of all breast malignancies in this study. The most frequent morphologic type was diffuse large B-cell lymphoma. As patients with primary breast lymphoma have a better prognosis than those with carcinoma of the breast or patients with extranodal lymphomas, a multidisciplinary approach including surgery, radiotherapy, and chemotherapy when needed would result in a more favourable outcome

Significance of immunohistochemistry in accurate characterization of malignant tumors

To determine in a large series of surgical biopsies the role and significance of immunohistochemistry in the adequate and accurate characterization of malignant tumors. A retrospective study of 20,000 consecutive surgical biopsies reported in the Section of Histopathology, AKU in 2003. Data was obtained by retrieving the filed surgical biopsy reports in the section. Out of the 20,000 biopsies, 6534 [32.67%] were neoplastic. 4726 neoplasms [72.33%] were malignant, and 1808 [27.67%] were benign. Immunohistochemistry was performed on 29.49% of malignant tumors, and 4.97% of benign tumors. Immunos were performed on only 2.82% of routine squamous cell carcinomas and adenocarcinomas of various organs, and in only 1.9% of infiltrating breast carcinomas, the commonest malignant tumors in females. In contrast, immunos were performed on 97.12% of non-Hodgkin's lymphomas, 97.94% of Hodgkin's lymphomas, 98.09% of malignant spindle cell neoplasms, 87.96% of small round blue cell tumors of childhood, 87.30% of neuroendocrine neoplasms, and 84.37% cases of malignant melanomas. In addition, immunos were performed on all cases of malignant undifferentiated neoplasms and were able to resolve the issue in over 89% of such cases. Immunos were also performed on 54.74% of metastatic tumors. Lymph nodes were the commonest organs on which immunos were performed i.e. 96.50% of lymph node tumors, followed by CNS and renal neoplasms with 33.01% and 25.92% respectively