Cutaneous Presentation of a Testicular Germ Cell Tumor With Seminomatous Differentiation
Testicular germ cell tumors typically present as an innocuous testicular mass that follows a reliable growth pattern. Undiscovered or neglected cases tend to grow locally and spread internally, making cutaneous presentations exceedingly rare. We present the case of a neglected, aggressive, testicular germ cell tumor with seminomatous differentiation that fungated through the scrotum, presenting as a large, ulcerative, scrotal mass. We present this case to highlight testicular germ cells tumors as another important, albeit rare, cause of scrotal ulceration of which dermatologists and dermatopathologists should be aware.
A 43-year-old Honduran man with no known significant medical history presented to a rural health care clinic in Honduras with a large, right-sided, fungating scrotal mass (Fig. 1). He gave an 8-month history of a painless right-sided testicular mass that grew and ulcerated through the scrotum approximately 2 months before his presentation. On presentation, he was afebrile with stable vitals. A complete blood count was significant only for anemia (Hgb 9.5 g/L). A shave biopsy was done and consistent with necrotic tissue. He was empirically treated for bacterial, fungal, and protozoan (amebiasis) infections with minimal improvement. An abdominal computed tomography scan with contrast was obtained and revealed a 13.4 × 17.8 × 19.9 cm pelvic mass involving the bilateral testicles, root of the penis, and infiltrating the right iliopsoas.
A deeper shave biopsy was then performed, which demonstrated diffuse solid sheets of slightly basophilic, uniform, atypical cells with abundant clear cytoplasm, which contained nuclei with granular chromatin and prominent nucleoli (Fig. 2). Robust mitotic activity was noted. These cells were separated by fibrous septra admixed with a lymphocytic infiltrate, and, at times, were noted to form cords and tubular structures. The tumor cells were strongly immunoreactive for Oct4, placental alkaline phosphatase, podoplanin (D2-40), C-Kit (CD117), and CD10. Similarly, they were nonreactive for CK7, CK20, pancytokeratin (AE1/AE3), S-100, CD30, CD45, alpha fetoprotein, and beta-human chorionic gonadotropin. Taken together, the histopathological and immunohistochemical findings were most consistent with the diagnosis of a germ cell tumor with seminomatous differentiation. Unfortunately, the patient died shortly after the diagnosis was made.
A seminoma is an uncommon germ cell tumor arising from the germinal epithelium of the seminiferous tubules. It represents about half of the cases of testicular cancer.1 It typically presents as an incidentally discovered, unilateral, painless testicular lump or swelling in a middle-aged man. Pure testicular seminomas tend to have a very favorable prognosis as the disease is often caught early, and it is exquisitely sensitive to radiotherapy and chemotherapy. Undiscovered disease tends to grow locally and spread predictably along the lymphatic system to the paraaortic and pelvic lymph nodes.
Although the histologic and immunostaining pattern2 was most compatible with the diagnosis of a seminoma, the neoplasm in our patient did not behave in a manner typical of a pure seminoma. Because only a small biopsy was obtained from the mass, we favor to classify this neoplasm as a germinal cell tumor with local seminomatous differentiation and wonder if the seminomatous differentiation in the biopsy was coexisting with other germinal patterns in the tumor, which would help to explain the rapid and aggressive growth pattern. Unfortunately, the entirety of the tumor could not be examined to confirm this suspicion.
Indeed, it has been noted that certain seminomas feature large nuclei and increased mitotic activity, as was seen in our case. Interestingly, attempts to correlate these histological features with tumor behavior and outcome have been largely inconclusive, and there is currently no recommendation to assess for differentiation or anaplasia in seminoma.