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 119mEq/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, 100mg 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 15mg 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.