Spindle cell/pleomorphic lipomas (SCLs), cellular angiofibromas (CAFs) and mammary-type myofibroblastomas (MFBs) are rare benign mesenchymal tumors with monoallelic 13q14 deletion. They are predicted to have a common pathogenic mechanism due to shared similar histological and immunohistochemical features; however, pathological consequences of monoallelic 13q14 deletion remain unknown. We previously reported a CAF case with monoallelic 13q14 deletion in which the tumor expressed decreased levels of FOXO1 and RB1, both of which were encoded in 13q14, and increased reactive oxygen species (ROS) levels. We further demonstrated the activation of p38 mitogen-activated protein kinase (p38 MAPK) pathway induced by oxidative stress. We hypothesized that SCLs, CAFs and MFBs would share common molecular signatures involving FOXO1, ROS and p38 MAPK and that their expression patterns were different from those tumors without monoallelic 13q14 deletion such as solitary fibrous tumors (SFTs). We compared the expression levels of FOXO1, RB1, ROS markers and several signal transduction factors between SCLs and SFTs. SCLs expressed decreased levels of FOXO1 and RB1, whereas SFTs showed no change. Both tumor types exhibited increased markers of ROS; however, nuclear localization of phosphorylated p38 was significantly more frequent in SCLs than that in SFTs, suggesting p38 MAPK activation by oxidative stress. SFTs showed lower p38 MAPK activity and higher β-catenin expression, implying that oxidative stress was caused by increased cellular proliferation stress. Finally, CAFs and MFBs showed changes similar to those observed in SCLs. Overall, tumors with monoallelic 13q14 deletion showed shared molecular signatures that might be associated with pathogenesis.

BackgoundEndometrial mixed carcinoma with the neuroendocrine carcinoma (NEC) component is rare and is believed to have a poor prognosis. CD10 expression is reported to be a favorable prognostic marker for some tumors such as B-lymphoblastic leukemia/lymphoma, but unfavorable for others. Here, we report the case of a 33-year-old woman diagnosed with endometrial mixed carcinoma with the NEC component expressing CD10 who showed a favorable outcome.Case presentationThe patient presented with lumbago and brownish discharge from the genitals. Imaging modalities revealed a large exophytic mass in the uterine corpus, and a small one in the uterine cervix. Radical hysterectomy with bilateral salpingo-oophorectomy was performed. Microscopic examination of the endometrial and cervical masses revealed that the NEC component accounted for the maximum area in both masses. However, small areas in both lesions showed well differentiated endometrioid adenocarcinoma (WDEA) components, and histological transition between the two components was also observed. In addition to CD56 and synaptophysin expression, the NEC component was positive for CD10 but negative for estrogen receptor (ER), progesterone receptor (PgR), and carcinoembryonic antigen (CEA). In contrast, the WDEA component expressed both ER and PgR, but neither CD10 nor neuroendocrine markers were demonstrated. The CD10 and neuroendocrine markers clearly distinguished between the NEC and WDEA components. Furthermore, retained expression of phosphatase and tensin homolog (PTEN) and weak phosphorylated Akt expression were found, which were assumed to suppress the aggressive behavior of the tumor. The patient received postoperative chemotherapy and has survived without recurrence for 6 years after the operation.ConclusionThis is the first case of endometrial mixed carcinoma with the NEC component expressing CD10 that showed a long survival.