Shelekhova Ksenya V, Zhuravlev Alexander S, Krylova Daria D, Konstantinov Alexey S, Shtan Lidia V, Kheinshtein Valeriia A
1 Clinical Research and Practical Center for Specialized Oncological Care, Saint Petersburg, Russia.
2 Saint Petersburg Medico-Social Institute, Saint Petersburg, Russia.
Int J Surg Pathol. 2017 Sep;25(6):563-566. doi: 10.1177/1066896917707041. Epub 2017 Apr 28.
Only 28 cases of pseudomyxoma peritonei (PMP) arising from urachal neoplasms have been reported. We report one example of this extremely rare disease with KRAS mutational status in its spectrum of pathology. A 45-year-old woman presented with urachal frankly invasive mucinous cystadenocarcinoma confined to the dome of the bladder, which clinically manifested as PMP and was not detected at the first surgery. The primary tumour was revealed 6 months later because of its recurrence as PMP. Microscopic investigation revealed tubular adenoma and cystadenocarcinoma communicating with the bladder lumen and transitioning from the urachal urothelium to the mucinous epithelium. A urachal remnant was identified near the neoplasm. On immunohistochemistry, the tumour proved positive for CK7, CK20, CEA, and CDX2. Staining for β-catenin revealed expression in both the cytoplasm and cell membrane. Mismatch repair protein expression was normal. Somatic KRAS-mutation (G12V) was revealed in tubular adenoma, cystadenocarcinoma, and mucinous carcinoma peritonei and may play an oncogenic role in the malignant transformation of urachal mucosa and the development of PMP.
仅报道过28例源自脐尿管肿瘤的腹膜假黏液瘤（PMP）病例。我们报告了这一极其罕见疾病的1例病例，并阐述了其病理学范围内的KRAS突变状态。一名45岁女性患者，表现为脐尿管明显浸润性黏液性囊腺癌，局限于膀胱顶部，临床表现为PMP，初次手术时未被发现。6个月后因PMP复发发现了原发性肿瘤。显微镜检查显示管状腺瘤和囊腺癌与膀胱腔相通，并从脐尿管尿路上皮过渡到黏液上皮。在肿瘤附近发现了脐尿管残余。免疫组化显示，肿瘤CK7、CK20、CEA和CDX2呈阳性。β-连环蛋白染色显示在细胞质和细胞膜均有表达。错配修复蛋白表达正常。在管状腺瘤、囊腺癌和腹膜黏液癌中均发现了体细胞KRAS突变（G12V），其可能在脐尿管黏膜的恶性转化和PMP的发生中起致癌作用。
