Category: Pituitary Disorders/Neuroendocrinology
Objective : While prolactinoma is a frequently encountered diagnosis for endocrinologists, metastatic prolactinoma is exceedingly rare. As with other neuroendocrine tumors, the disease is defined by the presence of tissue outside of anatomic sites and there are precious few other clues to the diagnosis. We present a case of a patient with known prolactinoma presenting initially for resection of cervical meningioma which was subsequently found to be metastasis from her prolactinoma.
We present a 54 year old lady with rheumatoid arthritis, obesity, atypical prolactinoma admitted to our neurosurgical service for meningioma resection. She initiaally presented 6 years prior with peripheral visual field loss which prompted MRI brain. She underwent transsphenoidal resection two years later at an outside facility following failure of cabergoline 0.5mg day to halt growth on imaging .Her pathology report cited a 4.6 x 2.7 x 0.9 cm adrnoma with an MIB1 of 25%. Prolactin decreased to 322 from 4223. In the interim, she followed with an outside endocrinologist and was managed on 0.5mg cabergoline four times weekly. Her prolactin uptrended gradually to 1860 She concurrently developed BUE numbness and weakness. MRI showed a 3.6 cm intradural extramedullary right ventral mass consistent with a meningioma from the C2-C4 level. Surgical pathology showed pituitary carcinoma, prolactin positive.
Methods : NA
Results : NA
Metastatc prolactinoma is a rare disease, with about 50 reported cases. It is defined by by the presence of disease at extra-pituitary sites. There are precious few clues to the diagnosis, and the clinical course has significant overlap with benign tumors until the point of metastasis. Our case illustrates some of the most common features which may provide clues to the diagnosis, namely escape from dopamine agonist therapy and escalating prolactin levels in the face of stable pituitary imaging.
The mean time from initial diagnosis until metastasis diagnosis was 6.9 years amongst available data, and the mean time from diagnosis of metastasis until death was 1.9 years. Nonsurgical teatment options include high dose DA therapy, octerotide, tamoxifen, chemotherapy, and radiotherapy. Unfortunately, metastatic prolactinomas tend to be resistant to medical treatments, even at extreme doses (140mg daily bromocriptine in one study).
Unfortunately, our patient's postoperative course was complicated by PEA arrest and she was declared deceased on postoperative day 4.
Conclusion : Metastatic prolactinoma is a rare and difficult to treat disease. Equally difficult is prognosticating for the development of metastasis, though certain features do exist which should prompt consideration of metastatic transformation.
University of Utah, Utah
Final year endocrine fellow training at the University of Utah.