Late onset adrenal insufficiency after adrenalectomy due to latent nonclassical 21-hydroxylase deficiency: A case report.

Rationale: Adrenal incidentaloma is sometimes complicated with 21-hydroxylase deficiency (21-OHD). Latent nonclassical 21-OHD in incidentaloma is difficult to diagnose. Although adrenalectomy in 21-OHD has been conducted when malignancy could not be excluded, adrenal insufficiency sometimes occurs, and it might not be observed immediately after operation. Here, we report a case of a 71-year-old man who experienced adrenal insufficiency over 2 decades postadrenalectomy, leading to a diagnosis of latent nonclassical 21-OHD.

Patient Concerns: A 71-year-old man was admitted to the hospital due to difficulty in movements and a sodium level of 119 mEq/L. His medical history revealed precocious puberty and left adrenalectomy because of an incidentaloma at 49 years of age, diagnosed pathologically as an adenoma. He did not attend follow-up visits because he did not have any symptoms. In 2017, 3 months before hospitalization, he experienced general fatigue. A few days before admittance, he complained of difficulty in moving and visual hallucination of small animals.

Diagnoses: Laboratory evaluations revealed a high level of adrenocorticotropic hormone (ACTH) and low cortisol level. ACTH-stimulating test revealed a low basal level and low response for cortisol, and a high basal level and low response for 17-hydroxyprogesterone. We analyzed large gene deletion or conversion and the 9 most common micro mutations in the CYP21A2 gene by polymerase chain reaction; micro mutation of I172N and heterozygous large gene deletion or conversion were detected leading to the diagnosis of nonclassical 21-OHD.

Interventions: Immediately, 100 mg hydrocortisone was administered, followed by daily hydrocortisone and saline. The symptoms and hyponatremia improved in a few days. He was discharged from the hospital on day 34 with a daily dose of 15 mg hydrocortisone.

Lessons: Clinicians should be aware of late onset of adrenal insufficiency after adrenalectomy. In such cases, clinicians should not overlook the latent nonclassical 21-OHD.