Paper II
Question
A 35-year-old male presents with painless enlargement and heaviness of the right testis since 2 months. Ultrasound showed a hypoechoic and homogenous mass in the right testis (
- (a) What are the tumor markers that will help you in the diagnosis ( 3 mark(s)
- (b) How are testicular tumors classified ( 5 mark(s)
- (c) Describe the clinical features and gross and microscopic findings of any one testicular tumor. 7 mark(s)
Answer
(a) Tumour markers
- Alpha-fetoprotein (AFP): Elevated in yolk sac tumour and embryonal carcinoma (never in pure seminoma or choriocarcinoma)
- Beta-hCG: Elevated in choriocarcinoma, embryonal carcinoma; mildly elevated in some seminomas
- Lactate dehydrogenase (LDH): Non-specific marker of tumour burden, elevated in most germ cell tumours
- Placental alkaline phosphatase (PLAP): Can be elevated, particularly in seminoma
(b) Classification of testicular tumours
Germ cell tumours (95% of testicular tumours)
- Seminomatous: Seminoma (classic, spermatocytic)
- Non-seminomatous:
- Embryonal carcinoma
- Yolk sac tumour
- Choriocarcinoma
- Teratoma
- Mixed germ cell tumours (combination of the above)
Sex cord-stromal tumours
- Leydig cell tumour
- Sertoli cell tumour
(c) Clinical features, gross and microscopic findings — Seminoma (as the representative example)
Clinical features
- Most common testicular germ cell tumour, typically presents as a painless testicular enlargement (as in this patient), peak incidence in the 30s-40s
- Generally slow-growing with a relatively good prognosis, highly radiosensitive
Gross findings
- Homogeneous, bulky, grey-white to tan, well-circumscribed mass, often bulging on cut surface, typically lacking haemorrhage/necrosis (unlike non-seminomatous tumours) — consistent with the homogeneous hypoechoic mass on ultrasound described in this patient
Microscopic findings
- Sheets/nests of large, uniform tumour cells with clear/pale cytoplasm (glycogen-rich), distinct cell borders, and centrally placed round nuclei with prominent nucleoli
- Fibrous septa dividing the tumour into lobules, infiltrated by lymphocytes (a characteristic reactive lymphocytic infiltrate)
- May show scattered non-caseating granulomas
- Immunohistochemistry: positive for PLAP, OCT3/4, CD117 (c-KIT)