Ectopic secretion of LH by an endocrine pancreatic tumor

Abstract

Ectopic production of biologically active glycoprotein hormones other than hCG has been reported in exceptional cases. A 61-yr-old man came to our Unit complaining of weakness, fatigue and reduced libido with erectile dysfunction. There was also a history of polycythemia, known for about 10 yr and never further investigated. The physical examination showed acne and redness of facial skin and upper chest; no other significant abnormalities were detected. Serum levels of LH were very high, whereas α-subunit and hCG were only slightly increased. Testosterone and 17β-estradiol levels were increased too. Abdominal computed tomography (CT) scan revealed a large hypervascularized mass within the pancreatic tail, which was surgically removed by distal splenopancreatectomy. Diffuse immunoreactivity for LH was detected in more than 70% of the tumor cells. The α-subunit was also positive, while chorionic gonadotropin had only a focal reactivity. Reverse transcriptasepolymerase chain reaction (RT-PCR) and Southern Blot analysis confirmed the synthesis of LH by the tumor. Four weeks after surgery, serum levels of LH, α-subunit, testosterone, hCG and 17β-estradiol were all undetectable. The redness of facial skin and upper chest had disappeared, but libido was still reduced. At a further control, 3 months after surgery, serum levels of LH, FSH, hCG, α-subunit and 17β-estradiol were all within the normal range, as well as hemoglobin concentration and the red blood cells count. Testosterone was slightly below normal, but the patient reported an increase of libido. This is an unusual case of ectopic secretion of LH from an endocrine tumor of the pancreas.