case_images: PMC10764087_01
case_images: Image exams. a March 2017 - PET scan: hypermetabolic lesion in the peritoneum near the sigmoid rectum. b August 2019 - PET scan: increased peritoneum disease. c December 2019 - PET scan: increased peritoneum disease.
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case_images: PMC10764087_01_cro-2024-0017-0001-534179_F01.jpg
case_images: F1
case_images: In March 2017, almost 5 years after the initial diagnosis, a routine abdominal scan revealed a mass near the rectum and colon with an increased uptake in the 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) (Fig. 1a). BRCA2 pathogenic variant. But in August 2019, FDG PET/CT showed enlarged peritoneal lesions compatible with disease progression (Fig. 1b). In December 2019, FDG PET/CT showed recurrence of peritoneal disease (Fig. 1c).
case_images: Poor differentiated neoplasia in rectosigmoid wall composed by epithelioid cells with vesicular nuclei, numerous mitosis (a), and strong expression of GATA-3 (b); recurrence of neoplasia in peritoneum of retrouterine region with biphasic pattern: glandular spaces sharply juxtaposed with solid spindle and epithelioid cells (c), both positive to PAX-8 (d); glandular component of neoplasia with strong expression of cytokeratins, while sarcomatous component was negative (e) and inverse pattern with vimentin, diffusely positive in the sarcomatous component (f).
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case_images: PMC10764087_01_cro-2024-0017-0001-534179_F02.jpg
case_images: F2
case_images: This tumor was poorly differentiated and composed of epithelioid cells with a high nuclear-cytoplasmic ratio, vesicular nuclei, and conspicuous nucleoli (Fig. 2a). Table 1. The tumor was CDX2 negative, cytokeratin 7 positive, and cytokeratin 20 negative, excluding the potential of a primary intestinal tumor, and positive for GATA-3 (Fig. 2b); however, there was no estrogen or progesterone receptor expression, whereas they were highly expressed in the primary breast tumor. The retrouterine neoplasm also had a sharply juxtaposed mesenchymal component (Fig. 2c). The immunohistochemical profile was similar to the previous pelvic lesions, but the tumor showed PAX-8 expression (Fig. 2d). Staining for cytokeratins of 40, 48, 50, and 50.6 kDa (AE1/AE3) showed diffuse positivity in the adenocarcinoma component but no expression in the sarcoma component (Fig. 2e). Vimentin was positive in isolated cells of the adenocarcinoma component and diffusely positive in the sarcoma component (Fig. 2f). A new peritoneal biopsy sample was then obtained and confirmed the diagnosis of CS (Fig. 2).
case_images: Case report timeline.
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case_images: PMC10764087_01_cro-2024-0017-0001-534179_F03.jpg
case_images: F3
case_images: The case's events timeline is summarized in Figure 3.