Hyperprolactinemia due to pituitary adenoma is a rare causeof erectile dysfunction (ED). In this Letter, one such case inwhich erectile dysfunction preceded detection of pituitarymicroadenoma for many years is reported.A 35-year-old married man, not a known diabetic or hyper-tensive, presented with loss of libido and inability to achieve ormaintain erection for the past 8years. His morning erectionswere absent for the same duration. He was a non-smoker andnon-alcoholic and there was no history of prolonged substanceabuse.Therewasnohistoryoflocalorspinaltrauma.Hehadnoprior history of any psychiatric illness. General physical exam-ination revealed no gynecomastia, testicular atrophy or vari-cosities in scrotal area. Systemic and detailed neurologicalexaminations were also normal. Routine hematological andbiochemical investigations were within normal limits. PenileDoppler using high frequency probe showed normal corporacavernosa and spongiosium without evidence of any obviouscalcification. Cavernosal arteries were visualized and appearednormal, thus ruling out vascular cause of impotence. Contrastmagnetic resonance imaging (MRI) of the brain was normal,with homogenous enhancement of the pituitary.Four years after the onset of ED, he developed diminishedvision in the right half of both eyes. On direct questioning, thepatient revealed that he had intermittent accompanying head-ache, especially upon lifting heavy weights in the gymnasium.Repeat MRI scan showed a focal bulge on the left side of thepituitarygland,suggestiveofmicroadenoma.Hormonalprofilerevealed serum prolactin levels as high (31.6ng/ml; range =3.0–18.6ng/ml)andserumtestosteroneasnormal(9.6nMol/L;range for 20–50year-old men =4.56–28.2nMol/L). Serum FSHwas 4.01mIU/ml (range =1.55–9.74) and LH was 2.25mIU/ml(range=1.8–7.8). Thyroid hormone profile was normal. He wastreated with tablet cabergoline 0.25mg orally twice a week andthenincreasedto1mgorallytwiceaweek,afterwhichsignificantimprovement in both sexual function and visual deficits werereported.Clinicalpresentationofpituitaryadenomasmayvarydepend-ingonthelocationandsizeofthetumoranditssecretaryactivity.Adenomas are common during adulthood. Headaches, doublevision or other visual disturbances are usual presentations of apituitaryadenoma.Aprolactinomaisthemostcommonpituitaryadenoma leading to endocrine alterations with sexual conse-quences (e.g., amenorrhea, infertility, and gynecomastia).It is generallyrecognized that endocrinopathyis the rarest ofcauses of ED (Zeitlin & Rajfer, 2000). Obtaining serum testos-teroneandprolactinwithorwithoutthyroidhormoneprofilehasbeen advised as a cost effective screening tool to identify suchcases. Hyperprolactinemia per se is a rare cause of ED (Miller,Howards, & McLeod, 1980) as well but men with hyperprolac-tinemiareportsexualdysfunctionfrequently(Alfonso,Rieniets,&Vigersky,2006).ThiscaseillustratesthatEDcanbethesolepresenting feature of prolactin secreting pituitary tumors.References