# A Rare Prolactin-secreting Pituitary Carcinoma With Epidural and Thecal Metastases

## TL;DR

A rare case of a prolactin-secreting pituitary carcinoma with spinal metastases is described, highlighting diagnostic and treatment challenges.

## Contribution

This case report adds to the limited literature on pituitary carcinomas with epidural and thecal metastases.

## Key findings

- The patient had a prolactin-secreting pituitary tumor that progressed despite multiple treatments.
- Metastases occurred in the epidural space and thecal sac from the thoracic to sacral spine.
- Initial response to temozolomide chemotherapy was followed by disease progression.

## Abstract

Pituitary carcinomas are rare but associated with significant morbidity and mortality. They remain challenging to diagnose and manage. In this case, we describe a 56-year-old man who presented with erectile dysfunction and binocular vertical diplopia. He had central hypogonadism, secondary adrenal insufficiency, and central hypothyroidism on biochemical testing. His serum prolactin was 1517 mcg/L (1517 ng/mL; reference range 4-15 mcg/L), and his sellar magnetic resonance imaging showed a 2.0 × 2.2 × 3.1 cm pituitary tumor. Pathology revealed a prolactin-secreting carcinoma. Despite treatment with a high-dose dopaminergic, 2 transsphenoidal resections, and 1 course of radiation, prolactin levels continued to rise. He developed metastases to the epidural space and thecal sac from the thoracic to sacral spine, for which he received 12 cycles of temozolomide chemotherapy with initial clinical and biochemical response. This was followed by disease escape and progression. We discuss the clinical and imaging features that warrant a high index of suspicion for pituitary carcinoma and review contemporary treatment.