Diagnostic challenge of pulmonary embolism during testosterone replacement therapy for primary hypogonadism.

Testosterone replacement therapy (TRT) is widely used in the management of male hypogonadism to restore physiological androgen levels and improve related symptoms. Although generally considered safe under appropriate monitoring, its association with pulmonary embolism (PE) remains controversial. We report a case of a 50-year-old man who independently and progressively shortened testosterone injection intervals due to recurrent hypogonadal symptoms. Despite the absence of overt cardiopulmonary symptoms, diagnostic workup revealed bilateral PE. This case highlights an atypical presentation of PE in a male patient receiving TRT, in whom nonspecific symptoms such as fatigue and reduced exercise tolerance were initially attributed to hypogonadism, potentially masking an underlying life-threatening thromboembolic event. It underscores the importance of periodic reassessment of TRT, clinical vigilance for thrombotic complications, and improved risk-stratification tools to guide monitoring and management.