Introduction: Pituitary carcinomas are rare tumors with heterogeneous behaviors. Their carcinogenesis is unknown. The treatment is multimodal, non-standardized and radiotherapy can be used for local control of invasive adenomas.
Results: A 47-year-old man consulted for headaches, decreased libido, impaired vision and gynecomastia. A CT scan revealed a pituitary macroadenoma with suprasellar extension and invasion of the left sinus cavernosus and sphenoidal sinus. Prolactin levels were of 2750 ng/mL (reference value:<25 ng/mL). The patient began treatment with bromocriptine 2.5 mg/day, and underwent a transsphenoidal adenomectomy (TSA). Post-operatively the patient began prednisone, testosterone and levothyroxine therapy. Due to tumoral persistence with invasion to adjacent structures a transfrontal craniotomy was realized in the following year with sellar radiotherapy of 50 Gy. Subsequently, the patient presented a normal campimetry, prolactin levels of 88 ng/mL and symptomatic improvement. The patient remained asymptomatic for 5-years with concurrent bromocriptine treatment. Due to bromocriptine intolerance, he began cabergoline 1 mg/week. Posteriorly, prolactin rose gradually reaching levels of 1800 ng/mL, so he started therapy again with bromocriptine until reaching 40 mg/day. However, 6-years later he reported lumbar pain and a MRI scan showed a hypointense lesion in L1; confirming with biopsy a prolactinoma metastasis. Spine radiotherapy was administered with symptomatic improvement. Three TSA were later needed due to recurrence of the sellar lesion, with prolactin averaging levels of 1000 ng/mL. The patient, then with oligo-metastatic disease, declined any further treatment. He had a death associated with extensive cranial involvement, and survival of 6-years after initial metastatic diagnosis.
Conclusions: The clinical course in this patient was unusual. He presented a 14-year overall survival without any systemic antitumor therapy. While radiotherapy is used in recurrent and aggressive pituitary tumors in which surgery fails, we hypothesize that it contributed to the tumoral malignant transformation and the late resistance to dopaminergic analogues in our patient.
Patient Care: Our case report will show researchers and the medical community how important it is to investigate in therapeutic strategies for pituitary carcinomas. Due to the fact that we don’t know how tumors will behave in each patient, treatment is non-standardized and depends mainly on the judgement of the treating doctor and specific case. There is no possibility of evidence based medicine strategies in these types of patients. Likewise, new strategies through new and better research will permit us to better control these tumors and further prolong the survival of our patients. It will further remain a challenge to treat pituitary tumors, specially in patients whose tumoral aggressiveness affects much more patient’s survival than in our case.
Learning Objectives: By the conclusion of this session, participants should be able to:
1. Know that pituitary carcinomas present heterogeneous behaviors with patient’s overall survival being 14 years even after initial tumoral aggressiveness and metastatic diagnosis.
2. Understand that previous radiotherapy treatments may play an influential role in malignant tumor transformation and dopaminergic analogue resistance.
3. Understand why new randomized trials regarding survival and therapeutic strategies of pituitary carcinomas to further understand their pathophysiology are needed.
References: A macroprolactinoma becoming resistant to cabergoline and developing atypical pathology.
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