EMBRYOLOGY OF TESTIS Figure 2-1 EMBRYOLOGY OF TESTIS The gonad is first recognized at 4 to 5 weeks of gestation as a thickening of the intermediate mesoderm of the ventromedial aspect of the mesonephros, forming the genital, or gonadal, ridge. At 6 weeks, and simultaneously with the arrival of th... More

EMBRYOLOGY OF TESTIS Figure 2-2 EMBRYOLOGY OF TESTIS Early in development, the configuration of the gonad (in red) is elongated between the root of the dorsal mesentery and the mesonephros. (Fig. 16-17 from Sadler TW. Langman’s medical embryology, 12th ed. Philadelphia: Wolters Kluwer; 2011:243.)... More

GONADOBLASTOMA Figure 7-8 GONADOBLASTOMA Left: In this dissecting pattern (or undifferentiated gonadal tissue) small nests and cords of germ cells and sex cord cells closely resemble the infiltrative growth pattern of germinoma. Right: Cords of germ cells with sex cord cells surround two discret... More

FIBROTHECOMA Figure 6-143 FIBROTHECOMA An intratesticular gonadal fibrothecoma is well circumscribed, with a homogeneous gray-white cut surface. (Fig. 1A from Zhang M, Kao CS, Ulbright TM, Epstein JI. Testicular fibrothecoma: a morphologic and immunohistochemical study of 16 cases. Am J Surg Path... More

MYOID GONADAL STROMAL TUMOR Figure 6-166 MYOID GONADAL STROMAL TUMOR A circumscribed, nonencapsulated tumor with prominent blood vessels is seen in the testis. More

MYOID GONADAL STROMAL TUMOR Figure 6-167 MYOID GONADAL STROMAL TUMOR Spindled tumor cells are organized in short intersecting fascicles, with small, ectatic blood vessels. More

MYOID GONADAL STROMAL TUMOR Figure 6-168 MYOID GONADAL STROMAL TUMOR Strong and diffuse smooth muscle actin reactivity in the tumor as well as in peritubular myoid cells. More

MYOID GONADAL STROMAL TUMOR Figure 6-169 MYOID GONADAL STROMAL TUMOR Strong staining for S-100 protein. More

GONADOBLASTOMA AND UNDIFFERENTIATED GONADAL TISSUE Figure 7-7 GONADOBLASTOMA AND UNDIFFERENTIATED GONADAL TISSUE A: Confluent nests of gonadoblastoma (diffuse or expansile pattern), resembling germinoma on low power, are associated with classic nests of gonadoblastoma (top and bottom right). B: ... More

GONADOBLASTOMA Figure 7-1 GONADOBLASTOMA Bilateral gonadoblastomas with pink-tan cut surfaces contain white, “gritty” calcifications throughout; the gonad on the right also shows a solid white area of germinoma. Bilateral fallopian tubes are present. (Fig. 8 from Ulbright TM, Young RH. Gonadoblas... More

HAMARTOMATOUS NODULES Figure 6-81 HAMARTOMATOUS NODULES There are several discrete tan nodules measuring up to 2 cm in this gonad from a patient with androgen insensitivity syndrome. More

TESTICULAR “TUMOR” OF THE ADRENOGENITAL SYNDROME Figure 11-64 TESTICULAR “TUMOR” OF THE ADRENOGENITAL SYNDROME The lesional cells (top) are negative for androgen receptor whereas the nuclei of gonadal stromal cells and adjacent Sertoli cells are strongly positive (antiandrogen receptor immunostai... More

EMBRYOLOGY OF TESTIS Figure 2-6 EMBRYOLOGY OF TESTIS The primordial germ cells (left, red dots) derive from the yolk sac mesoderm and then migrate along the hindgut and its mesentery (right) to reach the gonadal (genital) ridges. (Fig. 16-18 from Sadler TW. Langman’s medical embryology, 12th ed. ... More

RUPTURED CORPUS LUTEUM IN AN OVOTESTIS Figure 11-96 RUPTURED CORPUS LUTEUM IN AN OVOTESTIS A hemorrhagic corpus luteum is present in the upper pole of an ovotestis of a patient with 46,XY ovotesticular disorder of sex development. The patient, a 14-year-old boy, presented with “testicular” pain a... More

POLYEMBRYOMA Figure 4-201 POLYEMBRYOMA This tumor predominantly consists of polyembryoma. It is mostly solid, with a few cysts, and has a lobulated and prominently hemorrhagic cut surface with occasional fibrous bands. (fig. 4-1 from Stall JN, Young RH. Polyembryoma of the testis: a report of two... More