Extragonadal Seminoma Presenting as a Large Mass in the Pelvic Cavity Without c-kit-activating Mutations

Abstract

Extragonadal germ cell tumors are relatively rare tumors, which usually occur in the mediastinum or retroperitoneum. In this report, we present a case of primary seminoma arising in the pelvic cavity. A 58-year-old man with urinary retention and abdominal distension was admitted to our hospital. Computed tomography and magnetic resonance imaging demonstrated a large mass in the pelvic cavity. Histological examination of the specimens obtained by open biopsy revealed seminomatous malignant cells. Immunohistochemical studies detected vimentin, placental alkaline phosphatase and c-kit. Taking these results together with the patient's other clinical manifestations, this case was diagnosed as extragonadal seminoma without c-kit-activating mutations, and chemotherapy followed by radiation therapy was successful. Primary seminoma in the pelvic cavity is extremely rare, but should be considered a cause of pelvic mass formation.

A Rare Cause of Mechanical Intestinal Obstruction: A Neoplastic Intra-Abdominal Testis

“…One of their cases involved an acute abdomen due to hemoperitoneum secondary to the mass bleeding directly into the abdominal cavity. 6,[8][9][10] In our case, the clinical presentation was caused by ileus. The patient's complaints were due to local and distant metastasis.…”

“…Seminoma is the most frequent type of tumor in primary bilateral cases, while malignant lymphoma is the most frequent bilateral testicular tumor. 5,6,10 Males with cryptorchidism are~5 to 15 times more likely to develop a testicular tumor than males without the condition. Cryptorchidism is more frequent on the right side.…”