Immunohistochemical Markers and the Clinical Course of Adenosarcoma: a Series of Seven Cases
Abstract Background: Uterine adenosarcoma, a rare subtype of uterine tumor, is a biphasic tumor consisting of epithelial and mesenchymal elements. There is no research comparing histopathological features of primary and recurrent tumors, including immunohistochemistry; furthermore, the relationship between pathology and the clinical course is unclear. We reviewed the pathology and immunohistochemical features of 7 adenosarcoma cases and investigated the relevance of the histomorphological features to the clinical course. We also compared immunohistochemical features of primary and recurrent tumors.Methods: Seven patients with adenosarcoma who underwent surgery in our hospital were evaluated. We performed immunohistochemical staining for the estrogen receptor (ER), progesterone receptor (PR), p53, and two SWI/SNF chromatin-remodeling proteins (SMARCA4, BCOR), which were recently developed for the diagnosis of undifferentiated sarcomas in addition to conventional staining methods. Results: All patients were International Federation of Gynecology and Obstetrics stage 1B to 1C. All tumors were polypoid, and every patient presented with abnormal uterine bleeding. Six patients were over 50 years old and were menopausal; 1 patient was under 50 years old and was non-menopausal (average age 59.1 years). Histologically, the sarcomatous components were homologous in 6 patients and heterogenous in 1 patient. Four patients were recurrent patients; 3 were non-recurrent. All 4 recurrent patients showed high-grade morphology with sarcomatous overgrowth and were negative for ER and PR. Three recurrences could be evaluated by imaging, showing recurrence only in a distant area; biopsy specimens from these tissues revealed the identical mesenchymal component found in the primary tumor without a benign epithelial component. Immunohistochemical staining results were also the same as for the original tumor, except for the p53 expression in 1 patient. At the primary site, p53 was overexpressed in 2 recurrent patients and had a wild-type level in 1 recurrent patient; however, all 3 recurrent tissues showed overexpression of p53. None of the 7 cases showed SMARCA4 loss, and BCOR expression was positive in 1 case.Conclusions: Initial pathological analysis of the adenosarcoma with appropriate immunohistochemical staining is vital for prognostic assessment. Expression of p53 might increase at recurrence. SMARCA4 and BCOR could be an index of malignancy, regardless of sarcomatous overgrowth.