Testicular Mass in a Young Man

Specimen Type:

Testis

History:

A 27-year-old man presented with testicular pain and was found a mass in the left testis. Received is a radical orchiectomy. Cut sections show the circumscribed hemorrhagic mass, measuring 3.3 x 3 x 3 cm located in the middle of the testis. The wall of the lesion is fibrotic. Most of the lesion is hemorrhagic with soft tan nodules. The largest nodule measures 1.5 cm. The mass does not infiltrate the adjacent testicular tissue. The tunica vaginalis is intact. The gross appearance of the epididymis and spermatic cord is unremarkable. Representive sections are submitted.

Pathologic Features:

Sections from the tumor reveal a well-circumscribed tumor with a fibrous capsule (Figure 1). The growth patterns are diffuse, nested, microfollicular, microcystic, and cystic (Fig 1, 2, 3, 4, 5). The tumor cells contain scant cytoplasm and pale, angular, or oval grooved nuclei (Fig 6); nucleoli are conspicuous in some areas and mitosis is present (Fig 7). Spindled cells are seen focally (Fig 8); there is prominent collagen production in some areas (Fig 9).

Differential Diagnosis:

  • Sex cord-stromal tumor, unclassified (Fig 10)
  • Granulosa cell tumor, adult type

Sex cord-stromal tumor, unclassified: The tumors in this category frequently lack specific differentiation or contain patterns and cells resembling to varying degrees both testicular and ovarian elements. Clinically, 10% of patients present with gynecomastica. Microscopically, a spectrum of patterns is seen, ranging from predominantly epithelial to predominantly stromal. The better differentiated tumors typically contain solid to hollow tubules or cords composed of cells resembling Sertoli cells, and islands of cells resembling granulosa cells. The less differentiated tumors exhibit varying degrees of nuclear pleomorphism and mitotic activity; diffuse and sarcomatoid patterns are frequent and it may be difficult or impossible to distinguish the epithelial and stromal components on routine staining. Spindle cell predominant cases are often reactive for S-100 and actin, similar to granulosa cell tumors.

Granulosa cell tumor, adult type: This is a distinct and rarest group of the sex cord-stromal tumors. The tumor typically occurs in adults with an average of 42 years. Grossly, the tumor is lobulated, brownish-yellow, and solid; cysts are sometime present. Microscopically, the tumor usually displays either microfollicular, with Call-Exner bodies, or diffuse patterns, but other patterns such as gyriform, insular, or macrofollicualr, may be observed. The cytoplasm is typically scanty, and the nuclei are pale with variably prominent grooves.

Diagnosis:

Granulosa cell tumor, adult type

Key Features

  • Grossly: partially or completely encapsulated; firm, lobulated, brownish-yellow
  • Microscopically:
    1. Admixture of a wide variety of patterns: predominant pattern: microfollicular or diffuse; Other patterns: gyriform, macrofollicular, insular, trabecular, solid, and pseudosarcomatous
    2. Microfollicular pattern with Call-Exner bodies is characteristic
    3. Tumor cells display scant cytoplasm and pale nuclei with characteristic grooves
    4. Fibrous or thecomatous stroma may be present
  • Immunohistochemically:
    1. Generally positive for vimentin and inhibin;
    2. Variably positive for actin;
    3. negative for AE1/AE3 and EMA

Comment: The major differential diagnosis is sex cord-stromal tumor, unclassified, in which a predominant pattern of testicular or ovarian differentiation is not clearly recognizable, which is not true of the findings in the current case. Diagnosis is based on an admixture of patterns including characteristic microfollicular with Call-Exner bodies, and identification of classic nuclear grooves. If the architectural features are typical of adult granulosa cell tumor, a paucity of nuclear grooves is still consistent with the diagnosis. Granulosa cell tumor in the testis is very rare with about 20 reported cases in the English literature (reference 1). Clinically, this group of tumors usually represents a slow-growing tumor that can potentially cause distant metastasis, which might take place several years after initial presentation. This characteristic clearly warrants long-term follow-up. A size greater than 7 cm, vascular/lymphatic invasion, and hemorrhage or necrosis are features of malignant tumors (reference 2).

References:

  1. Al-Bozom IA, El-Faqih SR, Hassan SH, et al. Granulosa cell tumor of the adult type: a case report and review of the literature of a very rare testicular tumor. Arch Pathol Lab Med. 2000 Oct;124(10):1525-8.
  2. Jimenez-Quintero LP, Ro JY, Zavala-Pompa A, Amin MB, Tetu B, OrdoƱez NG, Ayala AG. Granulosa cell tumor of the adult testis: a clinicopathologic study of seven cases and a review of the literature. Hum Pathol. 1993 Oct;24(10):1120-5.