HMGA gene rearrangement is a recurrent somatic alteration in polypoid endometriosis.

The pathogenesis of endometriosis is unclear, and several genetic, endocrine, immune, and environmental agents have been evaluated with no putative causative factors identified. Here, we show somatic genetic alterations involving HMGA1 (6p21) and HMGA2 (12q15) in 3 cases of polypoid endometriosis. The lesions involved the small bowel mesentery and perirectal soft tissue in 1 case and the posterior vaginal fornix and sigmoid colon serosa in 2 other cases, respectively. All had a polypoid configuration with cystically dilated irregular glands and fibrotic stroma, containing thick-walled vessels. Conventional cytogenetic analysis of 1 case showed 46,XX,t(5;12)(q13;q15) in all metaphases. Fluorescence in situ hybridization studies confirmed the balanced rearrangement of HMGA2. HMGA1 rearrangements were present in 2 additional cases. Rearrangements were exclusively found in the stromal component but not in the glandular component. These findings suggest that HMGA rearrangements likely contribute to the pathogenesis of endometriosis. However, additional studies are needed to better define the biologic role of this genetic alteration.

FOXL2 mutations in granulosa cell tumors occurring in males.

CONTEXT: Granulosa cell tumors comprise less than 5% of ovarian tumors in women and are much rarer in men, with only about 20 cases reported, to our knowledge. Recently, a somatic mutation of FOXL2 was reported in virtually all adult-type granulosa cell tumors in women. OBJECTIVE: To investigate FOXL2 mutations in granulosa cell tumors occurring in males. DESIGN: Five cases of an adult-type granulosa cell tumor from males were selected from the files of the Mayo Clinic. Nine other testicular tumors (1 juvenile granulosa cell tumor, 5 Leydig cell tumors, and 3 Sertoli-Leydig cell tumors) were evaluated for comparison. Inhibin immunostain was performed in all cases. DNA was extracted from formalin-fixed, paraffin-embedded tissue, followed by polymerase chain reaction and direct sequencing of FOXL2. RESULTS: All 5 cases had classic histopathologic features of the adult-type granulosa cell tumor. Inhibin was diffusely positive in all cases. FOXL2 402C→G (C134W) was identified in 40% (2 of 5) of the male, adult-type granulosa cell tumors. Of the 2 tumors positive for the mutation, 1 occurred in the testis of a man, and the other one affected the abdominal ovaries of a phenotypically male patient. All other testicular tumors were negative for the mutation. CONCLUSIONS: The FOXL2 402C→G (C134W) mutation is also present in adult-type granulosa cell tumors occurring in men, although in a smaller proportion when compared with the rates reported in women. FOXL2 mutational analysis can be a helpful in the diagnosis of granulosa cell tumors of the testis.