Primary extragastrointestinal stromal tumors: A clinicopathological and immunohistochemical study-A tertiary care center experience.

Background: Extra gastrointestinal stromal tumors (EGIST) are uncommon compared to their gastrointestinal counterparts. EGISTs involve omentum, mesentery, retroperitoneum, pancreas, and pelvis. Materials and Methods: Ten EGISTs were analyzed in this study from January 1995 to November 2011. They were analyzed with respect to clinical features, imageological, histopathological, and immunohistochemical findings. The immunohistochemical stains used were Smooth muscle actin (SMA), Desmin, S-100 protein, CD34 and CD-117. Results: There was slight female preponderance with wide age range. Four of the tumors were in retroperitoneum, three in mesentery, and two in omentum and one in pelvis. Histopathologically majority were spindle cell tumors. Immunohistochemically CD117 was consistently positive followed by CD34. Smooth muscle actin was positive in eight cases, S-100 protein and desmin were positive in two cases each. Conclusion: EGISTs are rare and should be considered in the differential diagnosis of the mesenchymal tumors and immunohistochemistry helps to confirm the diagnosis. Further study with better follow-up is desired to characterize these uncommon tumors.

Localized Resectable Genitourinary Sarcoma in Adult Korean Patients: Experiences at a Single Center

PURPOSE: To evaluate the clinicopathological characteristics and prognosis of localized resectable genitourinary sarcomas in adults. MATERIALS AND METHODS: Between September, 1996 and November, 2008, 18 consecutive cases of adults (12 men and 6 women; median age 48.8 years) who were treated for primary genitourinary sarcomas were identified. The following variables were analyzed: patient age, gender, body mass index, American Society of Anesthesiologists (ASA) score, primary organ, tumor histology, size, necrosis, Federation Nationale des Centres de Lutte Contre le Cancer (FNCLCC) grade, and surgical margin positivity. Recurrence-free survival and disease-specific survival were the study end-points. RESULTS: The most common presenting symptom was a palpable mass (six cases, 33.3%), the most common site was the kidney (six cases, 33.3%), and the most common histological subtype was leiomyosarcoma (eight patients, 44.4%). Complete resection with negative surgical margins was achieved in 13 patients (72.2%). The median follow-up period was 49.9 months (range 6.4 to 147.6). The recurrence-free survival rates at 1, 3, and 5 years were 81.6%, 66.5%, and 66.5%, respectively. Recurrence-free survival only associated significantly with ASA score (p=0.018). The disease-specific survival rate at 1, 3, and 5 years was 88.9%, 76.2%, and 67.7%, respectively. Disease-specific survival was associated significantly only with FNCLCC grade (p=0.042). CONCLUSION: Although genitourinary sarcomas in adults are a rare group of tumors with a poor prognosis, some patients may have a favorable prognosis. Our findings suggest that FNCLCC grade is the most important prognostic factor for these patients.

Epithelioid sarcoma of the foot with subsequent lesion in hand: metastatic lesion or second primary?

Epithelioid sarcomas (ES) are rare tumors of soft tissue that have a propensity to occur in the extremities. Epithelioid sarcomas are known to metastatise to draining lymph nodes and commonly to the lungs. Herein, a case of epithelioid sarcoma which recurred in an unusual site namely the distal phalanx of left middle finger, six months post amputation of the primary lesion in the left foot is being reported. The ipsilateral inguinal lymph node showed metastatic deposits. The tumor at both these sites had similar histology and an identical immunohistochemical (IHC) pattern showing reactivity to cytokeratin (CK), epithelial membrane antigen (EMA), vimentin (Vim) and CD34. This case is presented to record an unusual occurrence of ES in the distal phalanx of middle finger with an ES of foot. The metastasis of ES to the distal acral bones has not been documented till date.

Expression of CD99 in Pleomorphic Carcinomas of the Lung

Pleomorphic carcinoma of the lung (PCL) is characterized by a mixture of sarcomatoid and carcinoma components, and a poor prognosis. However, no immunophenotype of tumor markers has been characterized in PCL. To charaterize the immunophenotype for CD99 in PCL, we performed an immunohistochemical evaluation of PCLs for thyroid transcription factor-1 (TTF-1), cytokeratin (CK) 7 and 20, and for CD99. CD99 was found to be expressed in both carcinomatous (47%) and sarcomatous components such as spindle cells (92%) and giant cells (57%). In the case of spindle cells, CK7 was expressed in 6 cases (46%) and TTF-1 in 2 cases (15%), whereas for giant cells CK7 was expressed in 8 cases (57%) and TTF-1 in one case (7%). However, CK20 was not expressed in either the carcinomatous or sarcomatous components in any case. Thus, CD99 was found to be widely expressed in both sarcomatous and carcinoma component in PCL. A clinicopathological analysis showed no direct correlation between the expression of CD99 and the clinical indices (stage, survival rate, invasion) of PCL.

Metaplastic carcinoma of the breast--a rare breast tumour.

Malignant breast neoplasms consisting of mixtures of epithelial and mesenchymal elements, are a rarity. Pathogenesis of such diverse elements within obviously infiltrating carcinomas has been the subject of much controversy. After the advent of immunohistochemistry, it is now generally accepted that metaplasia of the epithelial elements of a carcinoma gives these lesions their pseudosarcomatous appearance. Hence the name metaplastic carcinoma is given to malignant breast neoplasms which show Cytokeratin positivity in both epithelial and mesenchymal elements. We recently encountered such a case, which is being presented here along with relevant review of literature.

Sarcoma epitelioide: un análisis clínico, patológico e inmunohistoquímico / Epithelioid sarcoma: a clinical, pathological and immunohistochemical analysis

The author study the clinical history of a patient who initially had a nodule in the left arm and the lesion was excised, had 7 recurrences in the left arm in the following twelve years. The histological examination of one of the nodules showed that it was composed mainly of large ovoid and polygonal cells with abundant eosinophilic cytoplasm, vesicular nuclei and prominent nucleoli. There was an average of 4 mitoses in every 10 high power fields and rare atypical mitoses. The tumor cells showed intense activity with keratin, epithelial membrane antigen and vimentin, and were negative for the CD 31 endothelial marker

S-100 protein in clear cell sarcomas of the tendon sheath.

Fourteen histologically proved specimens of clear cell sarcomas (CCS) of tendon sheaths were studied for the presence of S-100 protein. Eleven cases were strongly positive, and 2 cases were weakly positive. There was only one case which was absolutely negative for this protein. This technique was useful to diagnose tumours which were not only easily diagnosed as CCS or soft tissue melanomas, but also in the atypical and spindle cell variants of CCS which have to be weeded out of the large family of other morphologically allied soft tissue tumours.

Clear cell sarcoma of the kidney: a case report

Clear cell sarcoma of the kidney (CCSK) is a highly malignant childhood tumor, distinguished from classic Wilms' tumor by its propensity to metastasize to the skeletal system. Authors described a case of CCSK from a 3-year-old boy in the right kidney, showing various histologic features, such as classic, epithelioid, trabecular, neurilemmoma-like, cystic and entrapped collecting tubular pattern. Ultrastructurally epithelial differentiation was absent. Immunohistochemically, none of the intrinsic tumor cells showed positive staining with the antibodies against the keratin, S-100 protein, carcinoembryonic antigen, vimentin, desmin and myoglobin, suggesting primitive mesenchymal cell in origin.