Extramedullary hematopoiesis (EMH) is a phenomenon in which hematopoietic cells are found in sites other than the bone marrow. It is usually observed in the liver and spleen but may occasionally be found within solid tumors. The current case report presents a 69-year-old female patient who presented with a renal cyst. Histopathological examination following surgical removal of the cyst revealed a lining of oncocytic- and chromophobe-type cells with capsular invasion and a mass forming EMH with evident bone trabeculae within the cyst wall. Circulating hematopoietic stem cells in the blood and their colonization within tissues is discussed in the present case report, emphasizing certain types of renal cell carcinoma.

Tenascin (TN) is an extracellular matrix glycoprotein (ECM) that participates in embryogenesis and carcinogenesis. The aim of this study was to investigate immunohistochemically the expression of TN in the normal, hyperplastic, and neoplastic endometrium (endometrial adenocarcinoma). In the adenocarcinomas, the results were correlated with patient age, menopausal status, stage, grade, myometrial invasion, and vascular invasion. TN expression was studied in the following cases: proliferative endometrium (10 cases), early secretory endometrium (10), secretory endometrium (10), simple hyperplasia (15), complex hyperplasia (15), atypical hyperplasia (15), and endometrial adenocarcinomas (25). Staining of basal membranes and the cytoplasm of the stromal and epithelial cells was evaluated semiquantitatively. Positive staining was observed in the vascular and glandular basal membranes, stromal cells, and epithelial cells of proliferative, hyperplastic, and neoplastic endometrium. The difference in percentage of stained stromal cells between the neoplastic and the nonneoplastic (proliferative and hyperplastic) endometrium was significant (p<0.005). However, the percentage of stained epithelial cell area in hyperplasia was significantly higher than that of adenocarcinoma and functional endometrium (p<0.005). We conclude that TN is an extracellular matrix glycoprotein that plays a role in proliferation and possibly endometrial carcinogenesis.

Background. Development of neuroepithelial tumors from mature cystic teratoma is very rare. We present a case of oligodendroglioma developing inside mature cystic teratoma. Case. Eighteen-years-old female, right adnexal mass with solid and cystic areas was detected. Sections showed all three germ layers. Also, a tumoral lesion was observed in a glial fibrillary matrix. Tumor was composed of monotonous, uniform cells which have oval-round nucleus, perinuclear halo, and indistinct cytoplasm. GFAP, EGFR, P53 were positive. Conclusions. We diagnosed oligodendroglioma arising from mature cystic teratoma. There was no recurrence at the end of 13 months followup. The number of cases which have been reported in the literature is only a few.