Recurrent nasal bleed as initial presenting complaint: a rare complication of giant prolactinoma in a 39-year-old.

Introduction and importance: Giant prolactinoma is a rare endocrine disorder that presents with unusually large size and markedly high serum prolactin levels. The objective of this report is to show the aggressive invasive nature of giant prolactinoma with rare clinical presentation of recurrent nasal bleeds and the use of cabergoline in the successful management of patients having severe symptoms of extreme headaches and bitemporal hemianopia along with intracranial invasion of tumor. Case presentation: A 39-year-old married Asian male, presented with severe headaches, blurred vision in the left eye, and recurring nasal bleeding. Perimetry revealed bitemporal hemianopia. MRI showed a well-defined mass in the sellar/suprasellar region (3.7 × 4.0 × 3.8 cm). Initial prolactin levels were >4000 ng/ml and testosterone levels were 69 ng/dl (300-890 ng/dl). The patient after being diagnosed with Giant Prolactinoma started treatment with cabergoline which reduced prolactin levels to 14 ng/ml and the mass to 1.7 × 1.9 × 1.4 cm, though testosterone levels remained low at 134 ng/dl. Clinical discussion: Giant prolactinomas present significant diagnostic and therapeutic challenges due to their size, invasiveness, and resistance to conventional treatments. This case report demonstrates the successful management of a giant prolactinoma, treated initially with cabergoline that effectively reduced prolactin levels and tumor size, highlighting its role as a first-line therapy. Comprehensive management involved adjusting cabergoline dosage and introducing testosterone replacement therapy for hypogonadism. Conclusion: In conclusion, managing giant prolactinomas requires a multidisciplinary approach, with dopamine agonists as the cornerstone of treatment. Individualized strategies, adjunctive therapies, and regular monitoring ensure comprehensive care.