{Reference Type}: Case Reports {Title}: Diagnostic features of metastatic endometrioid carcinoma in a captive black-tufted marmoset (Callithrix penicillata). {Author}: de MacĂȘdo IL;de Sousa DER;Mattioli M;Borges BP;Mendes de Lima EM;de Castro MB; {Journal}: J Med Primatol {Volume}: 53 {Issue}: 4 {Year}: 2024 Aug {Factor}: 0.821 {DOI}: 10.1111/jmp.12727 {Abstract}: A captive marmoset developed metastatic endometrioid carcinoma (EnC), a rare uterine tumor in non-human primates (NHPs). The neoplasm showed marked microscopical malignant and tubulopapillary aspects, immunopositivity for pan-cytokeratin, CK7, estrogen receptor, and a high mitotic index (Ki-67). These features may contribute to the diagnosis and therapeutics of EnC in NHPs.