Late development of intraventricular papillary pituitary carcinoma after irradiation of prolactinoma.

BACKGROUND: Intracranial dissemination of pituitary adenomas is a rare event that does not equate malignancy. Most of the cases have been reported as metastases from pituitary carcinoma. A case of papillary pituitary carcinoma developed 12 years after radiotherapy for prolactin-secreting hormone pituitary adenoma is presented.

CASE DESCRIPTION: A 37-year-old woman was admitted for the second time with neurologic disturbance and hypertension. A gadolinium-enhanced magnetic resonance scan of the brain demonstrated a 50-mm enhanced mass (absent on previous studies) on the lateral ventricle, involving the left temporal lobe. The patient underwent a craniotomy and biopsy of the lesion that was consistent with pituitary carcinoma; it was immunoreactive to follicle-stimulating hormone, adrenocorticotropic hormone, pituitary tumor-transforming gene, and epithelial cell adhesion molecule. Transmission electron microscopy analysis confirmed the secretory pituitary tumor diagnosis.

CONCLUSIONS: The tumor was considered a primary pituitary papillary carcinoma. The clinical course indicated that this tumor was the seedling of a pituitary tumor, although it could be interpreted as metastases from a pituitary carcinoma.