Case 55 - Discussion

Uploaded: 2007-06-03, Updated: 2007-07-23

SERTOLI-LEYDIG CELL TUMOR

Comment:

The tumor is predominantly comprised of tubules and small nests of clear to intensely eosinophilic and granular cuboidal and columnar cells. The cells contain regular, vesicular nuclei with single, prominent nucleoli. A minor component of solid sheets of tumor cells with intensely eosiophilic cytoplasm and less vesicular nuclei are also present. No significant inflammatory infiltrate is seen. The tumor shows minimal cytological atypia with less than one mitosis per ten high-power fields. There is no lymphovascular invasion or tumor necrosis.  The borders are well-circumscribed and not infiltrating. The tumor stains positively for the immunohistochemical markers vimentin and inhibin, consistent with a tumor of sex-cord stromal origin and negatively for placental alkaline phosphatase (PLAP), which is often positive in seminomas. 

The sex cord-stromal tumors of the testis:

• Leydig cell tumor;

• Sertoli cell tumor;

• Sertoli-Leydig cell tumor;

• Granulosa cell tumor;
• Fibroma of gonadal stroma;
• Mixed type or indeterminate origin.

LEYDIG (INTERSTITIAL) CELL TUMOR

• Accounts for 1-3% of testicular tumors;
• Produces androgens, mainly testosterone, or combinations of androgens and estrogens;
• 20-60 years of age;

• Well-circumscribed nodules, usually 3-5 cm in diameter, sometimes lobulated;
• Cut surface: homogeneously solid and distinctive golden brown, 

• Most common patterns are diffuse and nodular. In diffuse pattern, the stroma is inconspicuous; the nodular pattern has prominent that may be broad and hyalinized. Occasionally, the stroma may be focally or conspicuously myxoid or edematous, and the tumor cells may be dispersed into relatively nests, clusters, trabeculae, cords, pseudotubues or ribbonlike patterns;
• Tumor cells are large and round or polygonal; Cell boundaries are often indistinct;
• Cytoplasm is abundant granular eosinophilic with a round central nucleus. The cytoplasm frequently contains lipid granules, vacuoles, or lipofuscin pigment, but most characteristically, rod-shaped crystalloids of Reinke occur in about 1/3 of the tumors;
• Indications for malignancy: larger, infiltrative margins, lymphovascular invasion, necrosis, high mitotic rate and significant atypia.

• Rare cases: spindle, ossification and psammoma bodies.

• Leydig cell hyperplasia: no discrete mass, multi-focal;
• Malakoplakia: von Hansemann cell, Michealis-Gutman bodies;
• Lymphoma;
• Large cell calcifying Sertoli cell tumor;
• Metastatic cancer.

• Positive: Inhibin, CK-LMW (patchy), Calretinin;
• Negative: PLAP.

• Prominent vesicles of SER, lipid droplets;
• Geometrically shaped Reinke crystals with striking periodicity.

• 10% of the tumors in adults are invasive and produce metastases; most are benign

• Robbins & Cotran Pathologic Basis of Disease;
• AFIP, 3rd series, 25

SERTOLI CELL TUMOR (ANDROBLASOMA)

• Accounts < 1% of testicular tumors;
• May elaborate estrogens or androgens;
• Associated with Peutz-Jeghers syndrome;

• These neoplasms appear  well-circumscribed, sometimes lobulated with a homogeneous gray-white to yellow cut surface.

• Tubular differentiation with hollow, round , solid or elongated pattern. Tumor cells may be arranged in distinctive trabeculae with a tendency to form cordlike structures resembling immature seminiferous tubules. The tumor is composed entirely of Sertoli cells or may have a component of granulosa cells.
• Tumor cells have moderate to occasionally abundant , eosinophilic cytoplasm. Cells may have cytoplasmic fine droplets or large vacuoles;
• Stroma may be scant or abundant, sometimes hyalinized or sclerotic;
• Indications for malignancy: large >5cm, significant atypia, necrosis, high mitotic rate >5/HPF, and lymphovascular invasion.

• Not otherwise specified type (NOS): most common, 70%;
• Large cell calcifying type;
• Sclerosing type.

• Positive: Inhibin, Vimentin, CK-LMW (patchy), focally positive for cytokeratin 7.
• Negative: PLAP, EMA, Calretinin.

• Tight junctions;
• Charcot-Bottcher filaments: perinuclear array of parallel cytoplasmic filaments;
• Prominant SER, RER, lipid droplets and interdigitating cell processes.

• Most Sertoli cell tumors are benign, but approximately 10% are more anaplastic and pursue a malignant course.

• Robbins & Cotran Pathologic Basis of Disease;
• AFIP, 3rd series, 25
• Johns Hopkins University, Unknown cases. Week 318: Case 1