Synchronous Low-grade Appendiceal Mucinous Neoplasm and Primary Peritoneal Low-grade Serous Carcinoma: A First Description of These 2 Neoplasms Presenting Together as Suspected Peritoneal Carcinomatosis.
Low-grade appendiceal mucinous neoplasm is a neoplasm typically of appendiceal origin, which is characterized by diffuse peritoneal involvement by pools of mucin with mucinous epithelium lacking high-grade cytologic atypia, and clinically presents as suspected peritoneal carcinomatosis. A similar clinical presentation can sometimes be seen with disseminated low-grade serous carcinomas of the peritoneum, fallopian tubes, or ovaries; however, this neoplasm is histologically characterized by tubal-type epithelium and invasive or confluent growth. In this case report, we describe a patient presenting with a clinical examination and radiologic features suggestive of peritoneal carcinomatosis and a prominent pelvic mass; however, after pathologic review, the patient was proven to have peritoneal involvement by both low-grade appendiceal mucinous neoplasm of appendiceal origin and a low-grade peritoneal primary serous carcinoma. In short, we present the first description of low-grade appendiceal mucinous neoplasm and serous carcinoma of the peritoneum presenting synchronously, providing morphologic characterization and immunohistochemical studies supporting the diagnosis, and illustrating a rare instance in which 2 neoplastic processes are underlying clinically suspected peritoneal carcinomatosis.
Department of Laboratory Medicine and Pathology (M.S., S.P.S., S.M.L.), University of Minnesota Department of Pathology (S.M.L.), Abbott Northwestern Hospital, Minneapolis, MN.
Miroslav
M
Sekulic
Simona
S
Pichler Sekulic
Saeid
S
Movahedi-Lankarani
D002288:Adenocarcinoma, Mucinous / Q000175:diagnosis* / Q000473:pathology; D001063:Appendiceal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D001065:Appendix / Q000473:pathology; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000175:diagnosis* / Q000473:pathology; D009852:Omentum / Q000473:pathology; D010053:Ovary / Q000473:pathology; D010534:Peritoneal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D010537:Peritoneum / Q000473:pathology