Ovarian Microcystic Stromal Tumor Research Articles

Ovarian Microcystic Stromal Tumor with Significant Nestin Expression: A Unique Case.

Ovary microcystic stromal tumor (MCST) is an extremely rare subtype of sex cord-stromal neoplasm, and only 57 cases have been reported. We herein report a unique case of ovarian MCST with positive nestin expression in a 39-year-old Chinese woman. The tumor showed microcystic stromal histological structures and characteristically expressed the CD10, WT-1, and Ki67 proteins. A molecular analysis identified a point mutation (c.110C > T) in exon 3 of the CTNNB1 gene. To our knowledge, no report has described a case of ovarian MCST with positive staining for nestin protein. Our study provides new insights into the tumor biology of ovarian MCST.

Ovarian microcystic stromal tumor with omental metastasis: the first case report and literature review

BackgroundMicrocystic stromal tumor (MCST) of the ovary is an extremely rare subtype of sex cord-stromal neoplasm first described by Irving and Young in 2009. Tumors from all previously reported cases (fewer than 40 total) were benign, but one was a case of ovarian MCST that reoccurred.Case presentationHerein, we present a unique single case of ovarian MCST with omental metastasis in a 47-year-old Chinese female along with its histologic and immunohistochemical profile and genetic alterations. The tumor exhibited the previously described classic microscopic features and immunoprofiles of MCST. The tumorlet in the omentum presented the same histological structures and characteristically expressed β-catenin protein (localized in the nucleus). Molecular analysis identified a point mutation (c.98C > G) in exon 3 of CTNNB1.ConclusionsTo the best of our knowledge, no such report has been documented for ovarian MCST with omental metastasis. The study may provide new insights into the tumor biology of MCST and provide a better understanding of this rare entity.

Distinct Immunophenotypic Features of Ovarian Microcystic Stromal Tumor

Distinct Immunophenotypic Features of Ovarian Microcystic Stromal Tumor

Ovarian Microcystic Stromal Tumor: Report of A New Entity with Immunohistochemical and Ultrastructural Studies

Microcystic stromal tumor is a recently described rare subtype of ovarian tumor for which there has been no previously reported ultrastructural study. We report a case with the characteristic histological and immunohistochemical features and the first ultrastructural study. The immunohistochemical findings of strong and diffuse nuclear staining for beta catenin and P27 are suggestive of dysregulation of more than one genetic pathway. The ultrastructural findings are supportive of the previous postulation of an ovarian stromal origin of the neoplastic cells.

β-catenin (CTNNB1) S33C Mutation in Ovarian Microcystic Stromal Tumors

Microcystic stromal tumor (MCST) is a recently described subtype of ovarian tumor characterized by prominent microcystic histologic pattern and diffuse immunoreactivity for CD10 and vimentin. However, its pathobiology, particularly its histogenesis, remains largely unclear. Here, we report 2 cases of ovarian MCST, in which we have performed extensive histologic, immunohistochemical, and genetic investigations to determine its distinct nature among ovarian neoplasms. The patients were 32 and 41 years of age. Both tumors were solid and cystic masses involving the right ovary. Microscopically, tumor cells with generally bland, round-to-ovoid nuclei grew in microcystic, macrocystic, and solid patterns. Intervening thick fibrous stroma was observed. Immunohistochemically, tumor cells were diffusely and strongly positive for CD10, vimentin, and Wilms tumor 1. Furthermore, we detected aberrant nuclear expression of β-catenin protein in both cases. Of interest, mutation analyses revealed the presence of an identical point mutation, c.98C>G, in exon 3 of β-catenin (CTNNB1) in both tumors. This is an oncogenic mutation that causes replacement of serine with cysteine at codon 33, leading to the loss of a phosphorylation site in the β-catenin protein. The results of this study strongly suggest that dysregulation of the Wnt/β-catenin pathway plays a fundamental role in the pathogenesis of ovarian MCST. Finally, by comparing the immunophenotype of MCST with its histologic mimics and other ovarian sex cord-stromal tumors, we were able to identify unique features of MCST and a panel of markers useful in differential diagnosis.