3.  A testicular biopsy in a 40-year-old patient shows a neoplasm consisting of cells with conspicuous nucleoli and clear cytoplasm arranged in a nesting pattern, as shown in this picture. Fibrous septae between neoplastic nests contain numerous lymphocytes. Mitotic figures are rare. Tumor cells are immunoreactive for placental alkaline phosphatase (PLAP). Which of the following is the most likely diagnosis?

  4.  A 70-year-old man undergoes orchiectomy for a testicular tumor. Histologically, the tumor consists of a polymorphic population of small, intermediate, and giant cells, as seen in this picture. Mitotic activity is present. Which of the following features is typical of this tumor?

  5.  A testicular tumor from a 30-year-old man consists of highly anaplastic epithelial cells with poorly defined borders arranged in papillary structures, as seen in this picture. Multifocal coagulative necrosis is noted. Neoplastic cells express CK8, CK18, and CD30. Which of the following is true about this tumor?

  6.  The most common testicular neoplasm in children less than 3 years of age is characterized by a spongy texture on the surface. Microscopically, its most typical pattern is characterized by fibrovascular cores “festooned” by tumor cells, as shown in this picture. Which of the following is it?

  7.  A testicular teratoma:

  8.  Which of the following testicular tumors is a specialized form of teratoma?

  9.  An 18-year-old male is evaluated for the acute onset of right hemiplegia. A CT scan shows a well-demarcated hemorrhagic mass in the left frontal lobe. The mass is removed and reveals the neoplasm shown in this photomicrograph. Further investigations lead to the discovery of a testicular tumor. Which of the following is the most likely diagnosis?

10.  Histologic analysis of an orchiectomy specimen reveals a neoplasm whose microscopic appearance is shown in this picture. Which of the following is the diagnosis?

11.  Histologic examination of a 2-cm testicular tumor from a 40-year-old man with gynecomastia shows sheets of polygonal cells with eosinophilic cytoplasm. Many rod-shaped intracytoplasmic crystals are identified, as shown in this picture. Electron microscopy reveals abundant smooth endoplasmic reticulum, mitochondria with tubular cristae, lipid droplets, and cytoplasmic elongated crystalloids. Which of the following is the most likely diagnosis?

12.  Which of the following histologic patterns is most characteristic of Sertoli cell tumors?

13.  Which of the following is a mixed germ cell–sex cord–stromal tumor that develops in patients with gonadal dysgenesis?