Adenocarcinoma in a Teratoma 24 Years After Initial Treatment

A patient in his 40s had been experiencing pain in his right lower abdomen for three weeks. He underwent orchiectomy and chemotherapy for a testicular tumor 24 years ago. Laboratory testing was unremarkable. A computed tomography scan was performed (Figure 1) which showed a retroperitoneal mass (approximately 10 cm in diameter) with displacement of the duodenum and compression of the infrarenal vena cava. Complete surgical resection of the tumor was performed. Histology revealed a metastasis of a teratoma with somatic malignancy, i.e., in addition to epithelial and mesenchymal components without nodular or inflammatory changes, a component of an adenocarcinoma of the colorectal type (Figure 2) was found with immunohistochemistry positive for CDX2 and CK20. No adjuvant chemotherapy was administered; the patient is receiving clinical follow-up care. Somatic malignancy is reported in 2.5–8% of (post-pubertal) testicular germ cell tumors, especially in teratomas; it can occur in the form of a sarcoma, carcinoma or immature neuroectodermal neoplasia and manifest in both the primary tumor and a metastasis, at times more than 30 years after the first diagnosis of a teratoma.

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Dr. med. Hinrich Böhner, Klinik für Viszeral- und Gefäßchirurgie SLG St. Paulus-Gesellschaft, St. Rochus-Hospital Castrop- Rauxel, [e-mail]

Dr. med. Franziska Hartmann, Prof. Dr. med. Andrea Tannapfel, Institut für Pathologie, Ruhr-Universität Bochum

Conflict of interest statement: The authors declare no conflict of interest.

Translated from the original German by Ralf Thoene, MD.

Cite this as: Böhner H, Hartmann F, Tannapfel A: Adenocarcinoma in a teratoma 24 years after initial treatment. Dtsch Arztebl Int 2025; 122: 264b. DOI: 10.3238/arztebl.m2025.0057