Question 1

Q: A 32-year-old woman presents with amenorrhea and galactorrhea. MRI shows a pituitary adenoma. Histological examination of the surgical specimen shows cells arranged in cords and nests with sinusoidal capillaries. Special staining reveals three distinct cell types: chromophobes (50%), acidophils (40%), and basophils (10%). Immunohistochemistry shows the tumor cells staining strongly for prolactin. Evaluate the relationship between normal pituitary architecture and tumor development to determine which cell type most likely gave rise to this neoplasm.

Lactotrophs (acidophils producing prolactin). ***Lactotrophs (acidophils producing prolactin)*** - These cells are classified as **acidophils** based on their staining characteristics and are responsible for the secretion of **prolactin**, consistent with the patient's **amenorrhea** and **galactorrhea**. - Although the tumor specimen contains various cell types, the **immunohistostaining** specifically identifying **prolactin** confirms these cells as the source of the neoplasm. *Somatotrophs (acidophils producing growth hormone)* - While these are also **acidophilic** cells, they secrete **Growth Hormone (GH)**, and a tumor of this type would present with **acromegaly** or gigantism rather than galactorrhea. - They do not typically stain for **prolactin**, unless the tumor is a rare plurihormonal adenoma, which is not indicated here. *Corticotrophs (basophils producing ACTH)* - These cells are **basophils** and produce **ACTH**; an adenoma arising from them would lead to **Cushing's disease** due to hypercortisolism. - Histologically, they would not correspond to the strong **prolactin** staining observed in this immunohistochemical evaluation. *Gonadotrophs (basophils producing FSH/LH)* - These are **basophilic** cells that produce **FSH** and **LH**, and tumors originating from them are usually non-functional or present with mass effects rather than hormonal excess. - They are clinically and histologically distinct from **prolactin-producing** lactotrophs. *Chromophobes (null cells with no secretory granules)* - **Chromophobes** lack significant cytoplasmic staining due to a lack of hormone granules; they often represent cells that have depleted their secretory stores. - While they occupy 50% of the specimen, the **strong prolactin staining** identifies the active neoplastic process as originating from the hormone-producing lineage.

Question

A 32-year-old woman presents with amenorrhea and galactorrhea. MRI shows a pituitary adenoma. Histological examination of the surgical specimen shows cells arranged in cords and nests with sinusoidal capillaries. Special staining reveals three distinct cell types: chromophobes (50%), acidophils (40%), and basophils (10%). Immunohistochemistry shows the tumor cells staining strongly for prolactin. Evaluate the relationship between normal pituitary architecture and tumor development to determine which cell type most likely gave rise to this neoplasm.

Accepted Answer

Lactotrophs (acidophils producing prolactin)

Answer

Somatotrophs (acidophils producing growth hormone)

Answer

Corticotrophs (basophils producing ACTH)

Answer

Gonadotrophs (basophils producing FSH/LH)

Answer

Chromophobes (null cells with no secretory granules)

Organ-specific histology — MCQs

Organ-specific histology — MCQs

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