Lost to Follow-Up: Complications of an Invasive Giant Prolactinoma

Abstract

Invasive giant prolactinomas are a rare type of prolactin-secreting tumors. Most lactotroph adenomas, including giant prolactinomas, consist of the sparsely granulated subtype and respond well to medical therapy with dopamine agonists. Proptosis due to intra-orbital tumor extension and ischemic infarction are two rare complications associated with these tumors. We report a case of a 51-year-old woman with a 30-year history of a macroprolactinoma who was lost to follow-up and returned with severe proptosis, a 10-cm invasive sellar mass on imaging, and markedly elevated serum prolactin levels, consistent with invasive giant prolactinoma. She was initially managed with dopamine agonists followed by palliative debulking of the tumor, which microscopically demonstrated a highly proliferative neoplasm predominantly consisting of sparsely granulated lactotroph adenoma with a minor component of the rare and aggressive acidophil stem cell adenoma subtype. Postoperatively, she developed a large left middle cerebral artery infarct and ultimately died. This case is notable in that it demonstrates the aggressive nature of invasive giant prolactinomas when not treated and highlights two rare findings in patients with this tumor: orbital invasion and ischemic infarct.

A giant invasive macroprolactinoma with recurrent nasal bleeding as the first clinical presentation: case report and review of literature

“…Immunostaining showed positive staining for PRL (B: magnification × 400) 100,000 patients. Prolactinomas are categorized based on their size, with microadenomas measuring < 1 cm, macroadenomas measuring > 1 cm, and giant prolactinomas, which are characterized by size > 4 cm, and PRL levels > 1,000 ng/mL [1]. Giant prolactinomas are rare tumors accounting for 0.5-1% of all pituitary tumors and 2-3% of prolactinomas [4].…”

“…Prolactinomas in men are often invasive tumors that grow rapidly, and they appear to have a more aggressive nature compared to females. The PRL level is high before treatment, and the size of the adenoma is directly proportional to the plasma PRL concentration [1]. The clinical manifestations of male hyperprolactinemia include erectile dysfunction, decreased libido, and infertility.…”

“…Invasive giant prolactinoma is one of the rare subtype of prolactin (PRL)-secreting pituitary neuroendocrine tumors (Pit-NETs), measuring > 40 mm, accounting for only 0.5% of all Pit-NETs, and 4.4% of all prolactinomas, often presenting with headaches, vision loss, hyperprolactinemia, hypopituitarism as the first clinical manifestations [1][2][3]. Therapeutic goals for prolactinoma include normalization of prolactin levels, significant tumor reduction, and restoration of function of the anterior and posterior pituitary gland.…”