A 28-year-old man comes to the office due to a bump on his right testicle. The patient is otherwise asymptomatic and healthy. Vital signs are normal. A solid mass is palpated in the right testicle. The rest of the examination is unremarkable. A scrotal ultrasound reveals a suspicious, partially necrotic mass. Serum lactate dehydrogenase and alpha-fetoprotein levels are markedly elevated. The patient undergoes a right radical inguinal orchiectomy. Which of the following is the most likely histologic diagnosis?

Question

A 28-year-old man comes to the office due to a bump on his right testicle.  The patient is otherwise asymptomatic and healthy.  Vital signs are normal.  A solid mass is palpated in the right testicle.  The rest of the examination is unremarkable.  A scrotal ultrasound reveals a suspicious, partially necrotic mass.  Serum lactate dehydrogenase and alpha-fetoprotein levels are markedly elevated.  The patient undergoes a right radical inguinal orchiectomy.  Which of the following is the most likely histologic diagnosis?

Quizplus · Accepted Answer

11ec160b_39a5_c8a0_9249_51ceec785c7d_MD0001_00 This patient's painless testicular lesion, necrotic mass on ultrasound, and elevated serum alpha-fetoprotein (AFP) level raises strong suspicion for testicular cancer, the most common solid organ malignancy in men age 15-35. Most cases (>95%) arise from pluripotent germ cells that normally differentiate into sperm (germ-cell tumors), which are categorized as follows: Non-seminomatous germ cell tumors (NSGCT) contain undifferentiated or partially differentiated germ cells (eg, embryonal carcinoma, yolk sac tumor, choriocarcinoma). They often generate abnormal hormones (human chorionic growth [hCG] hormone) or proteins (AFP) that can be measured in the blood to aid diagnosis and evaluate for recurrence following treatment. Seminomas contain large uniform germ cells that retain the phenotypic features of spermatogonia. They do not produce AFP but some seminomas secrete limited quantities of hCG. Lactate dehydrogenase (LDH), a marker of tissue injury and cell turnover, is also often elevated in patients with germ cell tumors but is less sensitive and specific than hCG or AFP. (Choice A) Leydig cells secrete testosterone and are found in the testicular stroma. Leydig cell tumors often produce estrogen or testosterone, leading to feminization (eg, gynecomastia) or precocious puberty, respectively. They do not generate AFP or hCG. (Choice C) Sertoli cells nourish sperm and secrete inhibin, which moderates pituitary gonadotropin release. Sertoli cell tumors are sometimes associated with the excessive production of estrogen but do not typically elevate AFP. (Choice D) Teratomas are terminally differentiated germ cells that may contain skin or gastrointestinal epithelium, cartilage, and/or neuronal tissue. They are often malignant in adults and may be part of some nonseminomatous germ cell tumors. However, terminally differentiated cells are not generally able to produce AFP or hCG; therefore, these tumor markers are usually not elevated. (Choice E) Primary testicular lymphoma is uncommon and usually occurs in men age >60. Although lymphoma can be associated with elevated LDH, AFP is almost always normal. Educational objective: Most cases of testicular cancer are either seminomatous or nonseminomatous germ cell tumors. Nonseminomatous germ cell tumors are composed of partially differentiated germ cells, which often retain the ability to secrete human chorionic growth hormone and alpha-fetoprotein (serum tumor markers). Serum lactate dehydrogenase, a marker of tissue injury and cell turnover, is also frequently increased. __________ References: The present and future of serum diagnostic tests for testicular germ cell tumours. (http://www.ncbi.nlm.nih.gov/pubmed/27754472)

A 28-Year-Old Man Comes to the Office Due to a Bump