A 50‑year‑old man lost hair, felt tired, and had low libido. Doctors found he had a rare hormone problem (isolated ACTH deficiency) and a testicular cancer. After surgery and steroid pills, his symptoms and hormone levels improved. The authors think the hair loss and hormone issue might be linked to the cancer through an immune reaction, and they suggest checking for hidden tumors when this hormone problem appears.

Idiopathic isolated adrenocorticotropic hormone (ACTH) deficiency (IAD) is a rare disorder. Its clinical presentation is nonspecific, with primary manifestations including fatigue, weakness, nausea, vomiting, hyponatremia, hypoglycemia, and neuropsychiatric symptoms. This case report describes a patient with IAD who presented with alopecia areata as the initial manifestation, concurrent with a testicular germ cell tumor. To the best of our knowledge, this represents the first reported case of IAD presenting initially with alopecia areata, and an association with testicular germ cell tumors has not been previously described. A 50-year-old male presented with a significant reduction in scalp hair density, a decrease in the rest of the body's hair, whitening of new hair growth, loss of libido, fatigue, and poor mental health. The patient was diagnosed with idiopathic isolated adrenocorticotropic hormone (ACTH) deficiency (IAD) and testicular germ cell tumor. The patient was treated with oral glucocorticoids and the testicular germ cell tumor was successfully resected. At follow-up after 2 months, the patient's clinical symptoms improved significantly, ACTH and cortisol levels returned to near normal on recheck, estrogen levels decreased to normal, and glucocorticoids were discontinued with no significant adverse events. This report suggests that there may be a potential association between alopecia areata, IAD, and testicular germ cell tumors and that the pathogenesis may be related to the autoimmune response induced by paraneoplastic syndrome. Clinically, patients with IAD of unknown etiology need to be carefully screened for the possibility of neoplastic disease in all systems.