Prolactin secretion abnormalities in patients with the "syndrome of spotty skin pigmentation, myxomas, endocrine overactivity and schwannomas" (Carney complex).

Carney complex is a multiple neoplasia and lentiginosis syndrome. Acromegaly due to growth hormone (GH)-producing adenomas has been considered the only pituitary-related manifestation of the complex. In the present study, seven patients with Carney complex, who belonged to three unrelated kindreds and had relatives with acromegaly, were investigated for the presence of GH and prolactin (PRL) secretion abnormalities (familial cases). In addition, four patients with the complex and no family history of the complex were studied (sporadic cases). Seven of the patients were female and four were male; their mean age was 24.27 +/- 4.34 years. Sampling every 20 min for one hour in the morning and under fasting and unstimulated conditions was performed in all patients, for determination of serum PRL levels. Insulin-like growth factor-I (IGF-I) levels and magnetic resonance imaging (MRI) of the pituitary were also obtained. Patients who had elevated IGF-I levels underwent investigation for acromegaly by oral glucose tolerance test and thyrotropin-releasing hormone. Seven of the 11 patients (63.6%) had moderately high PRL levels (mean Z score value 2.12 +/- 0.66); three of these patients also had elevated IGF-I levels but a negative investigation for acromegaly. All patients had negative pituitary MRI. The patient with the highest PRL levels underwent 24-hour sampling every 20 min, which demonstrated a higher baseline secretion of this hormone with preservation of its circadian pulsatility. Hyperprolactinemia was present in two siblings and a parent-child pair. We conclude that prolactin hypersecretion, albeit mild, appears to be frequent in patients with Carney complex, is inherited in an autosomal dominant manner in kindreds with the syndrome, and may be associated with elevated IGF-I levels in some, but not all, patients.

Cytogenetic and microsatellite alterations in tumors from patients with the syndrome of myxomas, spotty skin pigmentation, and endocrine overactivity (Carney complex).

Carney complex (CC) is a familial multiple neoplasia and lentiginosis syndrome, transmitted in an autosomal dominant manner. It is the only familial form of cardiac and skin myxomas known and includes endocrine neoplasms causing Cushing's syndrome [primary pigmented nodular adrenocortical disease (PPNAD)] and acromegaly (GH-producing adenoma). The molecular defect leading to CC remains unknown, but was recently mapped to chromosome 2p16 by linkage analysis. This region has exhibited cytogenetic aberrations in atrial myxomas from patients with CC and harbors the hMSH2 and hMSH6 genes, which are involved in the preservation of microsatellite length stability of replicating human cells. In the present study, we examined 15 tumor and normal tissue specimens from 13 patients with CC [GH-producing adenoma (n = 1), adrenal tumors (PPNAD, n = 8), thyroid cancer (n = 1), normal adrenal gland (n = 1)] and 4 cultured cell lines [heart myxoma (n = 3) and eyelid myxoma (n = 1)]. Chromosome analysis was obtained by standard cytogenetic techniques. One of the myxoma cell lines and 3 PPNAD specimens contained multiple telomeric associations (tas). The normal adrenocortical tissue from a patient with PPNAD contained no apparent chromosomal anomalies, whereas the neighboring PPNAD tissue demonstrated tas. DNA was extracted from peripheral blood, tumor cell lines, and frozen or paraffin-embedded tissues and subjected to PCR amplification with primers from 64 microsatellite locations covering chromosomes 1 and 3-22 and 14 loci covering chromosome 2. The alterations detected were loss and gain of heterozygosity (LOH and GOH; 49% and 26%, respectively), deletions of both alleles (DEL; 10%), and microsatellite length instability (15%). GOH and LOH were the most frequent changes, with telomeric markers significantly over-represented (P < 0.05). Chromosomes 6, 11, 22, 10, and 19 demonstrated mostly LOH, GOH, or DEL in over 40% of the informative loci tested (73%, 59%, 47%, 46%, and 44%, respectively), whereas markers on chromosome 2 showed only microsatellite length instability (10%). The degree of genomic instability and its type were independent of tumor type (P > 0.1). We conclude that tumors and tumor cell lines from patients with CC demonstrate significant genomic, but not microsatellite length, instability. Thus, the CC gene(s) on chromosome 2p16 is different from the hMSH2 and hMSH6 genes and has dominant, rather than recessive, tumorigenic function. This gene(s) appears to be involved in the regulation of genomic stability of dividing cells, in particular the structure of telomeres in replicating chromosomes and/or the function of the mitotic apparatus.

Insulin resistance and acanthosis nigricans. Report of a case with antibodies to insulin receptors.

A 64-year-old black man presented with the syndrome of acanthosis nigricans and insulin-resistant diabetes mellitus requiring up to 3000 units of insulin per day. The patient's plasma contained circulating antibodies to insulin receptors thought to be responsible for the insulin resistance. The marked insulin resistance, the manifestations of acanthosis nigricans, the evidence of immunologic dysfunction by the absence of expected circulating antibodies to insulin, and the demonstration of circulating antibodies to insulin receptors put this patient in Kahn's category B of insulin resistance and acanthosis nigricans. There was no evidence of malignancy, lipodystrophy, or endocrine abnormality. The occurrence of acanthosis nigricans with insulin resistance due to binding of cell membrane insulin receptors by antibodies has been reported exclusively in women. This case report is the first description of a male patient with the syndrome of insulin resistance and acanthosis nigricans and focuses attention on features that might mislead one to suspect other causes of insulin resistance.