Granulosa cell tumour secretes:
**Core Concept**
Granulosa cell tumours are a type of sex cord-stromal tumour that arise from the ovarian stroma. They are known for their ability to secrete various hormones, leading to distinct clinical manifestations. The most notable hormone secreted by granulosa cell tumours is estrogen, which plays a crucial role in their pathophysiology.
**Why the Correct Answer is Right**
Granulosa cell tumours secrete estrogen through the action of aromatase, an enzyme that converts androgens into estrogens. This excess estrogen production leads to a range of clinical symptoms, including endometrial hyperplasia, vaginal bleeding, and in some cases, precocious puberty in children. The estrogen secreted by granulosa cell tumours is responsible for the characteristic histological features of these tumours, including the presence of Call-Exner bodies.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because granulosa cell tumours do not typically secrete prolactin. While prolactin-secreting tumours are a common cause of hyperprolactinemia, granulosa cell tumours are not associated with this condition.
**Option B:** This option is incorrect because granulosa cell tumours do not typically secrete growth hormone. Growth hormone-secreting tumours are a rare cause of acromegaly, but granulosa cell tumours are not associated with this condition.
**Option C:** This option is incorrect because granulosa cell tumours do not typically secrete antidiuretic hormone (ADH). ADH-secreting tumours are a rare cause of the syndrome of inappropriate antidiuretic hormone secretion (SIADH), but granulosa cell tumours are not associated with this condition.
**Clinical Pearl / High-Yield Fact**
It is essential to remember that granulosa cell tumours can present with a range of clinical symptoms, including endometrial hyperplasia and vaginal bleeding, due to excess estrogen production. These symptoms can be similar to those seen in other conditions, such as endometrial cancer or uterine fibroids, and a high index of suspicion is necessary for diagnosis.
**Correct Answer: A. Estrogen**