Neuroendocrine carcinoma in a mediastinal teratoma as a rare variant of somatic-type malignancy

Abstract

Somatic-type malignancy (STM), defined as any sarcoma, carcinoma, leukemia or lymphoma developing in a germ cell tumor, occurs in approximately 2% of all germ cell tumors. Neuroendocrine carcinoma developing in a mediastinal germ cell tumor has not been previously reported. We here describe a 22-year-old man who underwent resection of a 11-cm mediastinal teratoma which consisted of components of all three germ cell layers with prominent foci of fetal-like liver tissue. The liver areas were surrounded by primitive neuroendocrine structures with ductal and solid growth pattern with a high proliferation rate. We diagnosed an immature mediastinal teratoma with STM, specifically neuroendocrine carcinoma arising in a background of immature liver tissue. Comparative genomic hybridization of dissected tumor tissue revealed chromosomal gains at 12 in the teratoma and neuroendocrine carcinoma component. In summary, clinicians and pathologists should be aware of neuroendocrine carcinoma as a rare type of STM complicating mediastinal germ cell tumors.

Mediastinal Teratoma with Coexisting Adenocarcinoma and Carcinoid Tumor (Somatic-Type Malignancy): A Case Report with a Review of the Literature

“…However, Armah et al [8] described a renal teratoma similar to our case, where coexisting adenocarcinoma and carcinoid tumor were seen. While sarcomas and carcinomas have been described in association with mediastinal teratomas, neuroendocrine neoplasms appear to be especially rare, with only about 6 cases reported [7,9,10]. Mediastinal mature teratoma may rarely be associated with two different somatic-type malignancies, like carcinoid tumor and mucin-secreting adenocarcinomas, as in the present case report.…”

Mediastinal Teratoma with Neuroendocrine Features in 34-Year-Old Male with Syncope

“…Teratoma is the most common germ cell tumor and usually contains tissue derived from the ectodermal layer, whereas mesodermal and endodermal derived structures are more infrequent [ 2 ]. STM is defined as a germ cell tumor accompanied by a nongerm cell tumor such as sarcoma, carcinoma, leukemia, or lymphoma.…”

Neuroendocrine Carcinoma Arising in a Mediastinal Teratoma with Pulmonary Metastasis: A Case Report and the Chemotherapy Response

“…In another 6 cases of neuroendocrine tumors arising in an extragonadal retroperitoneum/pelvis teratoma, the prognosis was better due to detection at an early stage and a low malignant potential of the tumors, including carcinoid tumors (8)(9)(10)(11)(12)(13), in contrast to ovarian neuroendocrine carcinomas which were mostly diagnosed at an advanced stage with other malignant components (14,15). The first case of a neuroendocrine carcinoma arising in a mediastinal teratoma, as reported by Schaefer et al (4), was confined to the mediastinum, and the patient did not receive adjuvant chemotherapy after surgical resection. Thus, the response to chemotherapy has not been properly evaluated in neuroendocrine carcinomas arising in teratomas at extragonadal sites such as the mediastinum, retroperitoneum, and pelvis.…”

“…In general, advanced STM suggests a poor prognosis because it has been considered resistant to systemic chemotherapy, unlike GCT (2,3). To the best of our knowledge, only 1 other case of a neuroendocrine carcinoma arising in a mediastinal teratoma has been previously reported (4). However, the effect of systemic chemotherapy has not been established in these extragonadal teratomas with neuroendocrine carcinoma.…”