7926 Hypophysitis and Hypopituitarism Caused by Neurosyphilis in a Patient with Chronic HIV Infection

Disclosure: B. Malapur: None. M.G. Jakoby: None. Introduction: Neurosyphilis is now mostly limited to individuals with HIV infections. We present a case of neurosyphilis complicated by hypophysitis and hypopituitarism in an HIV patient. Case: A 44-year-old male with chronic HIV and noncompliance with antiretroviral therapy presented for evaluation of a rash and photophobia. A copper-colored maculopapular rash was observed on the face, trunk, palms, and lower extremities. Neurosyphilis was diagnosed based on positive RPR (titer 1:64) and treponemal antibodies in cerebrospinal fluid. Mild hyponatremia, systolic blood pressure < 100 mm Hg, and plasma glucose 68 mg/dL raised concern for secondary adrenal insufficiency, and 8 AM cortisol was 2.7 mcg/dL. ACTH level was inappropriately low (16 mcg/dL), and the patient was also found to have secondary hypothyroidism (free T4 0.4 ng/dL [0.5-1.3], TSH 1.25 mIU/L [0.45-1.33]) and hypogonadism (testosterone < 10 ng/dL [270-1070]), LH 1.0 mIU/mL [1.2-8.6]). MRI revealed a non-enhancing, hypointense 12 x 4 x 4 mm mass in the anterior pituitary. The patient was started on treatment for T. pallidum, antiretroviral therapy, and hormone replacement with hydrocortisone and levothyroxine. On evaluation six months later, hypogonadism had resolved (testosterone 387 ng/dL, LH 6.3), and repeat MRI demonstrated resolution of the pituitary mass. Unfortunately, the patient was subsequently lost to follow up. Discussion: Hypophysitis complicating neurosyphilis in adults is rare and appears to be documented entirely in the case report literature. The first two cases were published in the 1950’s, prior to awareness of HIV, and hypopituitarism resolving after treatment with penicillin was documented for one patient. The first case in an HIV patient was published in 2013, and a case in a patient confirmed to be free of HIV was published in 2015. This patient’s presentation and course is similar to other cases published to date, with headache and/or photophobia, diffuse pituitary enlargement or focal pituitary mass, hypopituitarism, and resolution of hormonal and anatomic abnormalities after treatment for neurosyphilis. Though hypophysitis and hypopituitarism appear to occur rarely, they should be considered in patients with suspected or confirmed neurosyphilis presenting with headache or photophobia and clinical or laboratory findings that may be due to anterior pituitary deficits. Presentation: 6/1/2024