Luteinizing hormone secreting adrenal tumour as a cause of precocious puberty

Ectopic bioactive luteinizing hormone secretion by a pancreatic endocrine tumor, manifested as luteinized granulosa-thecal cell tumor of the ovaries

Endocrine pancreatic tumors are rare neoplasms consisting of multipotent cells capable of secreting various bioactive substances causing characteristic clinical syndromes. Ovarian stromal hyperthecosis is characterized by varying degrees of luteinized stromal cell proliferation after sustained LH and/or human chorionic gonadotropin stimulation, clinically manifested by symptoms/signs of virilization resembling the polycystic ovary syndrome (PCOS). We report a case of ectopic bioactive LH production from a pancreatic endocrine tumor in a 33-yr-old woman with rapidly developing symptoms/signs of hyperandrogenism and markedly elevated serum androgen and LH levels leading to hyperthecosis and bilateral luteinized granulosa-thecal cell tumors of the ovaries. Although the patient was initially thought to have either severe PCOS or an LH-secreting pituitary tumor, an LH-producing pancreatic endocrine tumor bearing somatostatin receptors was demonstrated on scintigraphy with [111In]octreotide and abdominal imaging. Symptoms and signs of hyperandrogenism resolved after the resection of the tumor. Immunohistochemistry, in situ hybridization, and electron microscopy studies confirmed LH synthesis by the tumor cell. Although extremely rare, ectopic LH production from nonpituitary endocrine tumors should be considered in the differential diagnosis of hyperandrogenism, particularly when associated with highly elevated serum LH levels.

Androgen-regulated transcripts in the neonatal mouse testis as determined through microarray analysis

Androgens are required for normal spermatogenesis in mammalian testes. These hormones directly regulate testicular somatic cells that, in turn, support germ cell differentiation. However, the identity of genes under androgen regulation in the testis are not well known. In the present study, neonatal male mice (8 days postpartum) treated by testosterone propionate (TP) were used to study androgen action in the testis as evidenced by alterations in gene expression. Mice were treated with 0.5 mg of TP or dihydrotestosterone (DHT) or vehicle (oil), and testes were harvested 4, 8, and 16 h after treatment. Global gene expression was monitored by microarray analysis. Real-time reverse transcription-polymerase chain reaction was performed to confirm the microarray results. The methodology was verified by confirming the presence of previously characterized TP-regulated genes, including Pem in Sertoli cells and Cyp17a1 in Leydig cells. No significant differences in gene expression were found between TP- and DHT-treated samples. Microarray analysis identified 141, 119, and 109 up-regulated genes at 4, 8 and 16 h after TP treatment, respectively, and 83, 99, and 111 down-regulated genes at the same corresponding time points. The androgen regulation of the selected gene was verified further using testes from flutamide-treated adult mice and isolated Sertoli cells in culture. The data generated in the present study may serve as a foundation for hypothesis-driven research and provide insights regarding gene networks and pathways under androgen control in the testis.

Ectopic secretion of LH by an endocrine pancreatic tumor

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.