Mixed germ cell testicular tumor presenting as metastatic cutaneous choriocarcinoma

To the Editor: A 38-year-old man, with polysubstance abuse and hepatitis C infection, was admitted to the hospital with nausea and coffee-ground emesis. He reported a 2-week history of two anterior chest nodules. Cutaneous examination revealed a 2.1- × 1.7-cm firm, pink nodule with punctate hemorrhagic crust and overlying pseudovesiculation on his right upper lateral chest wall. Adjacent to this nodule was a 0.5- × 0.5-cm papule with similar features (Fig 1). Additionally, he was found to have a unilateral enlarged, firm testicular mass with greatest dimension of 4.2 cm. The remainder of his physical examination was unremarkable. Laboratory tests showed a hemoglobin level of 4.9 g/dL. The patient had a normal basic metabolic panel, white blood cell and platelet count, as well as liver and coagulation function tests. The β-human chorionic gonadotropin (β-hCG) was remarkably elevated at 55,540.0 mIU/mL. The erythrocyte sedimentation rate was 44 mm/h. Values for antinuclear antibodies, carcinoembryonic antigen, CA19-9, α-fetoprotein, prostate-specific antigen, and haptoglobin were all normal. His hepatitis C virus quantitative viral load was 143,577 IU/mL. Metastatic workup revealed retroperitoneal lymphadenopathy, numerous bilateral lung masses, and a duodenal mass. Brain magnetic resonance imaging showed multiple enhancing hemorrhagic masses. The cells were negative for placental alkaline phosphatase, a marker for seminoma. Testicular orchiectomy revealed mixed germ cell tumor, with more than 95% of choriocarcinoma and less than 5% seminoma. Biopsy of the chest nodule revealed cutaneous metastasis of choriocarcinoma. Within the dermis was a dense, nodular, and interstitial infiltrate of poorly differentiated atypical and hyperchromatic cytotrophoblasts, admixed with several multinucleated hyperchromatic and atypical syncytiotrophoblasts (Fig 2, A and B). The β-hCG was diffusely positive in the cytoplasm of syncytiotrophoblastic cells and placental alkaline phosphatase was negative, thus confirming the diagnosis (Fig 2, C). In a mixed germ cell tumor, any admixture of a pure germ cell tumor, such as choriocarcinoma, can exist. Choriocarcinoma can rarely be found in its pure form; however, it is most commonly seen as a component of a mixed germ cell tumor. In both forms, choriocarcinoma has a biphasic pattern consisting of mononucleated cytotrophoblast cells that lie in sheets to form villus-like structures and a plexiform arrangement of syncytiotrophoblast cells that secrete β-hCG.1Ulbright T.M. The most common, clinically significant misdiagnoses in testicular tumor pathology, and how to avoid them.Adv Anat Pathol. 2008; 15: 18-27Crossref PubMed Scopus (52) Google Scholar Choriocarcinoma has a marked tendency to metastasize early. Skin metastasis is rare with only 12 cases previously reported and generally correlates with a poor prognosis.2Chen X. Xu L. Chen X. Teng X. Zheng S. Testicular choriocarcinoma metastatic to skin and multiple organs. Two case reports and review of literature.J Cutan Pathol. 2009; 37: 486-490Crossref Scopus (13) Google Scholar Cosnow and Fretzin3Cosnow I. Fretzin D.F. Choriocarcinoma metastatic to skin.Arch Dermatol. 1974; 109: 551-553Crossref PubMed Scopus (26) Google Scholar reported the first case in 1974, and a patient with these findings died 10 days after the initiation of chemotherapy.4Cheng D.C. Jennings T.A. Slominski A. Mihm Jr., C.M. Choriocarcinoma presenting as a cutaneous metastasis.J Cutan Pathol. 1995; 22: 374-377Crossref PubMed Scopus (30) Google Scholar A third case described a patient who died 3 months after the appearance of his cutaneous metastatic lesion to the upper back.5Satoko S. Yoshihiro N. Hiroshi H. Metastatic testicular choriocarcinoma of the skin: report and review of the literature.Am J Dermatopathol. 1996; 18: 633-636Crossref PubMed Scopus (37) Google Scholar First-line treatment of testicular choriocarcinoma is chemotherapy. Our patient was treated with right radical orchiectomy and chemotherapy. He received whole-brain radiation therapy and two cycles of chemotherapy with etoposide and cisplatin. The patient is currently alive 6 months after his presentation. Mixed germ cell tumors usually present with testicular enlargement, pain, or distant metastases. Cutaneous metastases are usually violaceous to red, hemorrhagic, infiltrative subcutaneous nodules located on the trunk, back, head, and scalp.5Satoko S. Yoshihiro N. Hiroshi H. Metastatic testicular choriocarcinoma of the skin: report and review of the literature.Am J Dermatopathol. 1996; 18: 633-636Crossref PubMed Scopus (37) Google Scholar In young men, metastatic testicular choriocarcinoma should be included in the differential diagnosis of papules or nodules in these locations.