A Rare Form of Hypothyroidism

Shehzad Basaria, MD, and Milena Braga, MD


South Med J. 2002;95(5) 

In This Article

Abstract and Introduction

Secondary hypothyroidism is extremely rare. In the majority of cases, there is a genetic (gene mutations) or structural (mass effect or infiltration) basis for central hypothyroidism, and there is simultaneous deficiency of other adenohypophysial hormones. Isolated deficiency of thyrotropin is even rarer. This report features the case of a woman who had isolated thyrotropin deficiency, with the remainder of the anterior pituitary hormones being normal. The various causes of central hypothyroidism and the role of the thyrotropin-releasing hormone test are briefly described.

The prevalence of secondary hypothyroidism is extremely low.The majority of the cases have either a genetic or structural basis for central hypothyroidism. The majority of these patients are also deficient in other anterior pituitary hormones. Isolated thyrotropin deficiency represents the rarest form of secondary hypothyroidism.This report describes a symptomatic woman with idiopathic isolated thyrotropin deficiency. The patient improved significantly with thyroxine replacement.