Testicular tumors

Testicular tumors

•         Divided into 2 major categories

–       Germ cell tumor (95 %).

–       Non Germ cell tumor derived from stroma or sex cord.

•         Most Germ cell tumors are highly aggressive cancer capable of rapid wide dissemination.

•         generally non Germ cell tumors are benign .

Germ cell tumors

•         Age affected between 15-34 years. In this age group they constitute the most common tumor in male & account approximately 10 % of all cancer death.

•         Much more common in whites than in blacks in ratio of 5:1.

•         Divided into 2 categories:

–       Seminoma (usually pure 40 %)

–       Non seminomatous (usually mixed 60 %) these are:

»       Embryonal carcinoma

»       yolk sac tumor

»       Teratoma

»       Choriocarcinoma

Pathogenesis

Several influences may be important

1-Cryptorchidism: 10 % of testicular tumor associated with undescended testis.

2-Genetic predisposition:

–       blacks more affected than whites.

–       familial clustering (10 folds increase risk in close relative).

3-Testicular dysgenesis: testicular feminization & klinefilter syndrome increase risk.

4-Isochromosome 12 (i 12p) are found commonly in these tumors.

Seaminoma

•         Divided into

–       Classical (85 %).

–       Anaplastic (5-10 %).

–       Spermatocytic seminoma (4-6 %).

•         Grossly: homogenous, gray-white, lobulated cut surface devoid from necrosis & hemorrhage.

•         Histology: sheets of uniform cell with clear cytoplasm contain glycogen with infrequent mitosis these cells arrange in poorly demarcated lobules by delicate septa of fibrous tissue contain T-lymphocytes.

Embryonal carcinoma

•         More aggressive than seminoma.

•         Grossly: small, variegated poorly demarcated at the margin with foci of necrosis & hemorrhage.

•         Histology: sheets of large anaplastic, angry-looking cells with high mitotic count grow in glandular or alveolar or tubular pattern.

Yolk sac Tumor (endodermal sinus tumor)

•         Most common testicular tumor in infants& children up to 3 years of age with very good prognosis.

•         In adult usually occurs in combination with embyronal carcinoma with bad prognosis.

•         Grossly: homogenous, yellow-white, mucinous appearance

•         Histology: lacelike network of cuboidal cells with Schiller-Duval bodies (glomeruli-like structure), with central capillary & mesodermal core.

•         Cell contains eosinophilic, hyaline-like globules in which AFP can be demonstrated.

Choriocarcinoma

•         Highly malignant form of testicular tumor that is composed of both cytotrophoblast & sycytotrophoblast

•         commonly occurs in mixture with other germ cell tumors.

•         Grossly: small nodule with foci of hemorrhage & necrosis, rapidly growing.

•         Secrete HCG

•         Histology: mixture of syncytotrophoblast (large cell with many irregular hyper chromatic nuclei & abundant eosinophilic cytoplasm which is + ve for HGC) & trophoblast (polygonal cell with clear cytoplasm & single uniform nucleus).

Teratoma

•         Group of complex tumor derived from more than one germ cell layer.

•         pure form are fairly common in infant & children.

•         In adults occur in combination with other Germ cell tumor mostly embryonal carcinoma.

•         Grossly: heterogeneous large mass with solid sometime cartilaginous & cystic areas.

•         Histology: 3 types

1- Mature teratoma: different type of mature tissue e.g., neural, muscle, cartilage, bits of intestinal wall, bronchial epithelium, thyroid, skin...

2- Immature teratoma: elements of 3 germ layers but incompletely differentiated e.g., poorly formed cartilage, neuroblasts, loose mesenchyme & cluster of glandular structure. They consider as malignant variant.

3- Teratoma with malignant transformation: focus of clear cut squamous cell ca, adenocarcinoma, carcinoid or sarcoma.

Tumors of sex cord-gonadal stroma

Two main types

–       Leydig cell tumor.

–       Sertoli cell tumor.

Leydig cell tumor:

•         Occurs between 20-60 years of age.

•         common presenting features are testicular swelling, gynecomastia & sexual precocity in children.

•         Tumor elaborate androgens or androgen & estrogens.

•         Most are benign. Only 10 % invasive

•         Grossly: homogenous golden brown circumscribed nodule

•         Histology: polygonal cell with abundant granular eosinophilic cytoplasm with lipofuscin pigment &  rod-shaped Reinke crystalloids.

Sertoli cell tumor:

•         Same age group as Leydig cell tumor.

•         May composed entirely of Sertoli cells or may have a component of granulosa cells.

•         Some induced endocrinologic changes, either androgen or estrogen may be elaborated.

•         Most are benign but 10 % are malignant.

•         Grossly: firm small nodule with homogenous gray-white to yellow cut surface.

•         Histology: uniform cells arrange in cord-like structures resembling immature seminiferous tubules.

Testicular Lymphoma

•         Account for 5 % of testicular neoplasm & constitute the most common form of testicular cancer in men over the age of 60 years.

•         Grossly: Gray-white homogenous mass.

•         Histology: almost all cases of diffused large cell lymphoma.

•         Prognosis: extremely poor.