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 alpha-subunit and hCG were only slightly increased. Testosterone and 17beta-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 alpha-subunit was also positive, while chorionic gonadotropin had only a focal reactivity. Reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern Blot analysis confirmed the synthesis of LH by the tumor. Four weeks after surgery, serum levels of LH, alpha-subunit, testosterone, hCG and 17beta-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, alpha-subunit and 17beta-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.

Gastrointestinal Neuroendocrine Tumors: Pancreatic Endocrine Tumors

“…In addition to the well-established PET syndromes (Table 1), small numbers of patients are described with PETs producing other biologically active substances and new syndromes have been proposed, although in most cases too few patients have been described to clearly establish this point or its spectrum. GI tumors have been described secreting luteinizing-hormone causing masculinization15, secreting renin causing erythrocytosis16 and secreting PYY causing constipation (primarily ovarian tumors)17.…”

Ovarian hyperstimulation secondary to ectopic secretion of follicle-stimulating hormone. Literature review prompted by a case

“…The authors suggest a possible gonadotropin secretion by the tumor, but there is no definitive diagnosis. We have found three clinical cases of LH secretion, two of them by pancreatic tumors (20,21) and one by an adrenocortical tumor (22), and gonadotropin secretion by urogenital tumors (23). Exceptional cases of ovarian hyperstimulation associated with severe primary hyperthyroidism (24) and with granulosa cell tumors (25) have been described.…”

Pancreatic neuroendocrine tumors: Clinical features, diagnosis and medical treatment: Advances

“…An enteroglucagon secreting PET has been described mimicking a glucagonoma but also with giant duodenal villi present which resembles features reported with renal/duodenal NETs secreting enteroglucagon as well as a metastatic NET of unknown primary secreting GLP-1, GLP-2 and PYY (Table-2) [22–25]. Other hormone-excess states due to over-secretion of gastrointestinal hormones by gastrointestinal tumors have been described including ovarian tumors ectopically secreting PYY resulting in constipation [20,21]; secreting renin or aldosterone causing alteration in blood pressure; secreting serotonin causing the carcinoid syndrome and secreting GLP-1 and somatostatin resulting in diabetes and reactive hypoglycemia. These latter functional tumors are usually not characterized as pNETs although the resemble aspects of pNETs as many are NETs.…”

“…In addition to these generally accepted pNET subtypes, there are a number of other very rare pNETs with functional syndromes in which only a few cases have been reported (Table-2). These include pNETs ectopically secreting erythropoietin resulting in erythroblastosis [16]; pNETs secreting renin resulting in hypertension [17]; pNETs secreting GLP-1 or IGF-2 which is associated with hypoglycemia [18,19]; and pNET secreting luteining hormone causing masculinization [20,21]. An enteroglucagon secreting PET has been described mimicking a glucagonoma but also with giant duodenal villi present which resembles features reported with renal/duodenal NETs secreting enteroglucagon as well as a metastatic NET of unknown primary secreting GLP-1, GLP-2 and PYY (Table-2) [22–25].…”