A Rare Presentation of Adrenal Insufficiency: Isolated Adrenocorticotropic Hormone Deficiency and Miyelofibrosis

ABSTRACT

Isolated adrenocorticotropic hormone (ACTH) deficiency is a rare cause of hypocortisolism, mostly associated with lymphocytic hypophisitis (LYH). Autoimmune miyelofibrosis is another rare autoimmune disease causing bone marrow fibrosis. Here, we report the case of a patient who presented with common symptoms (weakness, fatigue, weight loss, vague pain) and anemia and was diagnosed with both rare autoimmune disorders (lymphocytic hypophisitis and autoimmune myelofibrosis). A 34-year-old male presented with weakness, fatigue, weight loss, and diffuse musculoskeletal pain. He had mild normochromic normocytic anemia. Further investigations revealed bone marrow fibrosis. The World Health Organization criteria were not fulfilled for the diagnosis of primary myelofibrosis. Since his symptoms could not be explained by mild anemia, a thorough evaluation was performed which revealed hypocortisolism associated with undetectable ACTH. Insulin-induced hypoglycemia test yielded insufficient response of ACTH and cortisol. Sellar MRI demonstrated typical features of LYH. Resolution of all the symptoms and anemia was achieved with low-dose glucocorticoid replacement therapy. In conclusion, when evaluating a patient presenting with fatigue, weight loss, vague pain, backache, and mild anemia, hypocortisolism also should be kept in mind in the differential diagnosis. If the case is isolated ACTH deficiency, the most probable cause is LYH. In such a case, additional endocrinological or non-endocrinological autoimmune disorders are likely to be present. We report the first case of lymphocytic hypophysitis coexisting with autoimmune myelofibrosis.