Mutations of the gene encoding the protein kinase A type I-alpha regulatory subunit in patients with the Carney complex.

Carney complex (CNC) is a multiple neoplasia syndrome characterized by spotty skin pigmentation, cardiac and other myxomas, endocrine tumours and psammomatous melanotic schwannomas. CNC is inherited as an autosomal dominant trait and the genes responsible have been mapped to 2p16 and 17q22-24 (refs 6, 7). Because of its similarities to the McCune-Albright syndrome and other features, such as paradoxical responses to endocrine signals, genes implicated in cyclic nucleotide-dependent signalling have been considered candidates for causing CNC (ref. 10). In CNC families mapping to 17q, we detected loss of heterozygosity (LOH) in the vicinity of the gene (PRKAR1A) encoding protein kinase A regulatory subunit 1-alpha (RIalpha), including a polymorphic site within its 5' region. We subsequently identified three unrelated kindreds with an identical mutation in the coding region of PRKAR1A. Analysis of additional cases revealed the same mutation in a sporadic case of CNC, and different mutations in three other families, including one with isolated inherited cardiac myxomas. Analysis of PKA activity in CNC tumours demonstrated a decreased basal activity, but an increase in cAMP-stimulated activity compared with non-CNC tumours. We conclude that germline mutations in PRKAR1A, an apparent tumour-suppressor gene, are responsible for the CNC phenotype in a subset of patients with this disease.

The triad of paragangliomas, gastric stromal tumours and pulmonary chondromas (Carney triad), and the dyad of paragangliomas and gastric stromal sarcomas (Carney-Stratakis syndrome): molecular genetics and clinical implications.

Carney triad (CT) describes the association of paragangliomas (PGLs) with gastrointestinal stromal tumours (GISTs) and pulmonary chondromas (PCH). A number of other lesions have been described in the condition including pheochromocytomas, oesophageal leiomyomas and adrenocortical adenomas; CT is a novel form of multiple endocrine neoplasia (MEN), a genetic condition with a female predilection. Inactivating mutations of the mitochondrial complex II succinate dehydrogenase (SDH) enzyme subunits SDHB, SDHC and SDHD have been found in familial and sporadic PGLs, and gain-of-function mutations of the oncogenes c-kit (KIT) and platelet-derived growth factor receptor A (PDGFRA) cause sporadic and familial GISTs. We recently reported an international series of patients with CT, 34 females and three males (median age of presentation 21 years) who did not carry SDHA, SDHB, SDHC, SDHD, KIT or PDGFRA gene mutations. Comparative genomic hybridization revealed a number of DNA copy number changes. The most frequent and greatest contiguous change was a deletion within the 1pcen13-q21 region, which harbours the SDHC gene. Another frequent change was loss of 1p. Although GISTs showed more frequent losses of 1p than PGLs, the pattern of chromosomal changes was similar in the two tumours despite their different tissue origin and histology; the findings were consistent with a common genetic aetiology of these two tumours in CT. In a separate condition, in which the association (or dyad) of GISTs with PGLs is inherited in an autosomal dominant manner (Carney-Stratakis syndrome, CSS), germline mutations of the SDHB, SDHC and SDHD genes (but not KIT or PDFGRA) were found; GISTs in this condition were caused by SDH deficiency. We conclude that CT is a novel MEN syndrome whose genetic defect remains elusive. CSS is caused by SDH defects, suggesting that sarcomas (GISTs) can be caused by defective mitochondrial oxidation, consistent with recent data implicating this enzyme in a variety of endocrine and other tumours. The above have clinical implications (i) for patients with GISTs that are cKIT- and PDGFRA-mutation negative: these tumours are usually resistant to treatment with currently available tyrosine kinase inhibitors and may be part of a syndrome such as CT or CSS; and (ii) for patients with an inherited PGL syndrome, family history should be explored to identify any other tumours in the family, and in particular other endocrine lesions and GISTs.

An electron microscope study of canine cardiac myosin and some of its aggregates.

The morphology of the canine cardiac myosin molecule has been investigated in the electron microscope with Hall's mica-replica technique. The molecule is an elongated rod (shaft) of nonuniform diameter with a globular expansion (head) on one end. Statistical analysis of the lengths of 1908 molecules showed that the mean length was 1610 +/- 250 A; the mean length of the head was 210 +/- 20 A; and the diameter of the head and that of the shaft were 35 to 40 and 15 to 20 A, respectively. About one-third of the molecules had single or multiple, fairly sharp, angulations along their shafts. Rarely, some details of the substructure of the molecule have been observed. Large, spindle-shaped aggregates, measuring 0.5 to 1 micro in length and 50 to 100 A in diameter, were produced by dilution of the myosin solutions. These aggregates were readily visualized in the electron microscope by means of Huxley's negative-staining technique. Projections often were visible along the length of the aggregates except at a central zone where they were frequently absent. The aggregates resembled the thick myofilaments of the myocardium and appeared similar to those produced by Huxley from skeletal myosin solutions.

A calcified lung tumour and microcytic anaemia in a young woman: partial expression of the Carney triad.

The Carney triad is the non-familial addociation of gastric stromal tumours (GISTs), pulmonar chondromas and extra-adrenal paragangliomas. Fewer than 100 cases of the disorder have been reported since its description in 1977. The condition has a predeliction for young women. Most patients exhibit only two of the three components. The tumours tend to be multifocal in the affected organ or system. Herein, we describe the case of a 27-year-old woman with multiple gastric GISTs and a pulmonary chondroma, partial expression of the Carney triad. It is important to be aware of the Carney triad when one of its constituent tumours is found, particularly if the patient is a young woman, so that a search can be made for and surveillance instituted for the other components. Treatment for the gastric tumours (sarcomas) and the paragangliomas (potentially malignant) is surgical. The lung chondromas are benign neoplasms and ordinarily not symptomatic. If a diagnosis of the tumour can be established by biopsy, surgical resection may not be necessary.

Carney complex, a familial multiple neoplasia and lentiginosis syndrome. Analysis of 11 kindreds and linkage to the short arm of chromosome 2.

Carney complex is an autosomal dominant syndrome characterized by multiple neoplasias, including myxomas at various sites and endocrine tumors, and lentiginosis. The genetic defect(s) responsible for the complex remain(s) unknown. We studied 101 subjects, including 51 affected members, from 11 North American kindreds with Carney complex. Blood samples were collected from patients and their family members. Hospital records, photographs, and tissue specimens of deceased individuals were reviewed. DNA was extracted from blood samples, patient-derived cell lines, and/or paraffin-embedded tissues. Linkage analysis was performed with highly polymorphic microsatellite markers, distributed over areas of the human genome harboring the most likely candidate genes. The most prevalent clinical manifestation in patients with Carney complex was spotty skin pigmentation, similar to that observed in Peutz-Jeghers and other lentiginosis syndromes. Skin and cardiac myxomas, Cushing syndrome, and acromegaly were present in 62, 30, 31 and 8 percent of the patients, respectively. Linkage was obtained for three markers on the short arm of chromosome 2 (2p16), with a maximum two-point lod score of 5.97 at theta = 0.03 for the marker CA-2 (odds in favor of linkage 10(6):1. The flanking markers CA7 and D2S378 defined a region of approximately 6.4 cM that is likely to contain the gene(s) associated with Carney complex. Candidate genes in the proximity, including the propiomelanocortin and the DNA-mismatch repair hMSH2 genes, were excluded. We conclude that the genetic defect(s) responsible for Carney complex map(s) to the short arm of chromosome 2 (2p16). This region has exhibited cytogenetic aberrations in atrial myxomas associated with the complex, and has been characterized by microsatellite instability in human neoplasias.

Carotid body tumors in humans: genetics and epidemiology.

Genetic factors in the etiology of carotid body tumors (CBT) were sought in a medical record review of 222 histologically diagnosed cases at 12 U.S. medical centers. Patients in the series, which had a marked female predominance (146 females:76 males), usually developed tumors between the fourth and seventh decades of life (mean, 44.7 yr). In 16 patients who also had other extra-adrenal paragangliomas, suggesting a multiple primary tumor syndrome, CBT were diagnosed significantly earlier (mean, 35.4 yr; P less than 0.01). The occurrence of thyroid cancer in 5 other patients appeared to be excessive. Familial CBT was recognized in 16 patients from 13 affected families, including 9 newly ascertained kindreds. Compared with non-familial lesions, familial CBT tended to develop bilaterally (38% vs. 8% unilaterally) and at slightly earlier ages (41.6 vs. 44.9 yr). CBT was reported to occur in an autosomal dominant pattern in some families and within sibships in others; relatives were not examined for confirmation. The familial findings are generally consistent with a two-step mutation model of the development of hereditary and nonhereditary CBT; apparent deviations from the model might be clarified with additional data on this rare neoplasm.

Chromosome 2 (2p16) abnormalities in Carney complex tumours.

Carney complex (CNC) is an autosomal dominant multiple endocrine neoplasia and lentiginosis syndrome characterised by spotty skin pigmentation, cardiac, skin, and breast myxomas, and a variety of endocrine and other tumours. The disease is genetically heterogeneous; two loci have been mapped to chromosomes 17q22-24 (the CNC1 locus) and 2p16 (CNC2). Mutations in the PRKAR1A tumour suppressor gene were recently found in CNC1 mapping kindreds, while the CNC2 and perhaps other genes remain unidentified. Analysis of tumour chromosome rearrangements is a useful tool for uncovering genes with a role in tumorigenesis and/or tumour progression. CGH analysis showed a low level 2p amplification recurrently in four of eight CNC tumours; one tumour showed specific amplification of the 2p16-p23 region only. To define more precisely the 2p amplicon in these and other tumours, we completed the genomic mapping of the CNC2 region, and analysed 46 tumour samples from CNC patients with and without PRKAR1A mutations by fluorescence in situ hybridisation (FISH) using bacterial artificial chromosomes (BACs). Consistent cytogenetic changes of the region were detected in 40 (87%) of the samples analysed. Twenty-four samples (60%) showed amplification of the region represented as homogeneously stained regions (HSRs). The size of the amplicon varied from case to case, and frequently from cell to cell in the same tumour. Three tumours (8%) showed both amplification and deletion of the region in their cells. Thirteen tumours (32%) showed deletions only. These molecular cytogenetic changes included the region that is covered by BACs 400-P-14 and 514-O-11 and, in the genetic map, corresponds to an area flanked by polymorphic markers D2S2251 and D2S2292; other BACs on the centromeric and telomeric end of this region were included in varying degrees. We conclude that cytogenetic changes of the 2p16 chromosomal region that harbours the CNC2 locus are frequently observed in tumours from CNC patients, including those with germline, inactivating PRKAR1A mutations. These changes are mostly amplifications of the 2p16 region, that overlap with a previously identified amplicon in sporadic thyroid cancer, and an area often deleted in sporadic adrenal tumours. Both thyroid and adrenal tumours constitute part of CNC indicating that the responsible gene(s) in this area may indeed be involved in both inherited and sporadic endocrine tumour pathogenesis and/or progression.

A transgenic mouse bearing an antisense construct of regulatory subunit type 1A of protein kinase A develops endocrine and other tumours: comparison with Carney complex and other PRKAR1A induced lesions.

BACKGROUND: Inactivation of the human type Ialpha regulatory subunit (RIalpha) of cyclic AMP dependent protein kinase (PKA) (PRKAR1A) leads to altered kinase activity, primary pigmented nodular adrenocortical disease (PPNAD), and sporadic adrenal and other tumours. METHODS AND RESULTS: A transgenic mouse carrying an antisense transgene for Prkar1a exon 2 (X2AS) under the control of a tetracycline responsive promoter (the Tg(Prkar1a*x2as)1Stra, Tg(tTAhCMV)3Uh or tTA/X2AS line) developed thyroid follicular hyperplasia and adenomas, adrenocortical hyperplasia and other features reminiscent of PPNAD, including late onset weight gain, visceral adiposity, and non-dexamethasone suppressible hypercorticosteronaemia, with histiocytic, epithelial hyperplasias, lymphomas, and other mesenchymal tumours. These lesions were associated with allelic losses of the mouse chromosome 11 Prkar1a locus, an increase in total type II PKA activity, and higher RIIbeta protein levels; the latter biochemical and protein changes were also documented in Carney complex tumours associated with PRKAR1A inactivating mutations and chromosome 17 PRKAR1A locus changes. CONCLUSION: We conclude that the tTA/X2AS mouse line with a downregulated Prkar1a gene replicates several of the findings in Carney complex patients and their affected tissues, supporting the role of RIalpha as a candidate tumour suppressor gene.

Cutaneous neuropathology in multiple endocrine neoplasia, type 2b.

Increase in masses of mixed (myelinated and nonmyelinated) nerve are observed in the dermis of clinically normal skin of patients with multiple endocrine neoplasia, type 2b (MEN 2b). Preliminary histochemical studies revealed nucleoside triphosphatase and nonspecific acid esterase. Electron microscopy showed axonal organelles, mild degeneration of axons, and numerous axons unassociated with Schwann cells. The normal-appearing skin in MEN 2b seems to contain abnormal nerve tissue development equally with the mucosal and the gastrointestinal tract.

Preoperative diagnosis of occult parathyroid hyperplasia by calcium infusion in patients with multiple endocrine neoplasia, type 2a.

Hereditary multiple endocrine neoplasia, type 2 (MEN 2) comprises medullary thyroid carcinoma (MTC) and bilateral pheochromocytoma; the syndrome includes two major variants, MEN 2a (normal appearance, parathyroid disease common) and MEN 2b (mucosal neuromas, Marfanoid habitus, parathyroid disease rate). Patients with MEN 2a may be normocalcemic, with normal basal serum immunoreactive parathyroid hormone (iPTH) levels, yet have parathyroid hyperplasia discovered during thyroid surgery. In an attempt to predict the presence of this occult parathyroid hyperplasia, we performed calcium infusion (15 mg Ca++/kg/4 hours) in six patients with MEN 2a, seven patients with MEN 2b, and eight normal subjects. iPTH was measured in samples taken at one hour intervals during the infusion with a sensitive radioimmunoassay (antiserum GP 1M [Arnaud]). The iPTH values (expressed as per cent of the basal value) in the normal, MEN 2a, and MEN 2b groups at the fourth hour were 38.0 +/- 3.8% (mean +/- SE), 79.2 +/- 7.2%, and 47.8 +/- 5.2%. These iPTH values for patients with MEN 2a were significantly different from normal (P less than 0.001) and from those of the patients with MEN 2b (P less than 0.001). All MEN 2a patients had parathyroid hyperplasia at cervical exploration; parathyroid histology in the MEN 2b patients was normal. Failure of iPTH suppressibility in the MEN 2a patients was not due either to the plasma calcitonin or to achieved serum calcium concentrations. The normal iPTH suppressibility in MEN 2b is consistent with the concept that the parathyroid disease in MEN 2a is genetically determined, and not secondary to MTC and high plasma calcitonin concentration. Calcium infusion combined with the measurement of serum iPTH levels may detect occult parathyroid hyperplasia in patients with MEN 2a, normocalcemia, and normal basal iPTH values. The identification and follow-up of similar patients should establish the natural history of this unusual parathyroid disease.

Clinical and molecular features of the Carney complex: diagnostic criteria and recommendations for patient evaluation.

Carney complex is a multiple neoplasia syndrome featuring cardiac, endocrine, cutaneous, and neural tumors, as well as a variety of pigmented lesions of the skin and mucosae. Carney complex is inherited as an autosomal dominant trait and may simultaneously involve multiple endocrine glands, as in the classic multiple endocrine neoplasia syndromes 1 and 2. Carney complex also has some similarities to McCuneAlbright syndrome, a sporadic condition that is also characterized by multiple endocrine and nonendocrine tumors. Carney complex shares skin abnormalities and some nonendocrine tumors with the lentiginoses and certain of the hamartomatoses, particularly Peutz-Jeghers syndrome, with which it shares mucosal lentiginosis and an unusual gonadal tumor, large-cell calcifying Sertoli cell tumor. Careful clinical analysis has enabled positional cloning efforts to identify two chromosomal loci harboring potential candidate genes for Carney complex. Most recently, at the 17q22-24 locus, the tumor suppressor gene PRKAR1A, coding for the type 1alpha regulatory subunit of PKA, was found to be mutated in approximately half of the known Carney complex kindreds. PRKAR1A acts a classic tumor suppressor gene as demonstrated by loss of heterozygosity at the 17q22-24 locus in tumors associated with the complex. The second locus, at chromosome 2p16, to which most (but not all) of the remaining kindreds map, is also involved in the molecular pathogenesis of Carney complex tumors, as demonstrated by multiple genetic changes at this locus, including loss of heterozygosity and copy number gain. Despite the known genetic heterogeneity in the disease, clinical analysis has not detected any corresponding phenotypic differences between patients with PRKAR1A mutations and those without. This article summarizes the clinical manifestations of Carney complex from a worldwide collection of affected patients and also presents revised diagnostic criteria for Carney complex. In light of the recent identification of mutations in the PRKAR1A gene, an estimate of penetrance and recommendations for genetic screening are provided.

Islet amyloidosis in a patient with chronic massive insulin resistance due to antiinsulin receptor antibodies.

We report islet hyperplasia, nesidioblastosis, and abundant islet amyloidosis (derived from islet amyloid polypeptide) in a case of severe insulin resistance due to a circulating antiinsulin receptor antibody. Massive chronic beta-cell stimulation (as well as noninsulin-dependent diabetes mellitus and insulinoma) appears to be associated with islet amyloid.

Genetic and histologic studies of somatomammotropic pituitary tumors in patients with the "complex of spotty skin pigmentation, myxomas, endocrine overactivity and schwannomas" (Carney complex).

Carney complex (CNC) is a familial multiple neoplasia and lentiginosis syndrome with features overlapping those of McCune-Albright syndrome (MAS) and other multiple endocrine neoplasia (MEN) syndromes, MEN type 1 (MEN 1), in particular. GH-producing pituitary tumors have been described in individual reports and in at least two large CNC patient series. It has been suggested that the evolution of acromegaly in CNC resembles that of the other endocrine manifestations of CNC in its chronic, often indolent, progressive nature. However, histologic and molecular evidence has not been presented in support of this hypothesis. In this investigation, the pituitary glands of eight patients with CNC and acromegaly [age, 22.9+/-11.6 yr (mean +/- SD)] were studied histologically. Tumor DNA was used for comparative genomic hybridization (CGH) (four tumors). All tumors stained for both GH and prolactin PRL (eight of eight), and some for other hormones, including alpha-subunit. Evidence for somatomammotroph hyperplasia was present in five of the eight patients in proximity to adenoma tissue; in the remaining three only adenoma tissue was available for study. CGH showed multiple changes involving losses of chromosomal regions 6q, 7q, 11p, and 11q, and gains of 1pter-p32, 2q35-qter, 9q33-qter, 12q24-qter, 16, 17, 19p, 20p, 20q, 22p and 22q in the most aggressive tumor, an invasive macroadenoma; no chromosomal changes were seen in the microadenomas diagnosed prospectively (3 tumors). We conclude that, in at least some patients with CNC, the pituitary gland is characterized by somatotroph hyperplasia, which precedes GH-producing tumor formation, in a pathway similar to that suggested for MAS-related pituitary tumors. Three GH-producing microadenomas showed no genetic changes by CGH, whereas a macroadenoma in a patient, whose advanced acromegaly was not cured by surgery, showed extensive CGH changes. We speculate that these changes represent secondary and tertiary genetic "hits" involved in pituitary oncogenesis. The data (1) underline the need for early investigation for acromegaly in patients with CNC; (2) provide a molecular hypothesis for its clinical progression; and (3) suggest a model for MAS- and, perhaps, MEN 1-related GH-producing tumor formation.

Primary pigmented nodular adrenocortical disease: reevaluation of a patient with carney complex 27 years after unilateral adrenalectomy.

A 45-yr-old man with primary pigmented nodular adrenocortical disease (PPNAD) is described. This patient underwent unilateral adrenalectomy for ACTH-independent Cushing's syndrome (CS) in 1969. Although his daily urinary free cortisol (UFC) excretion rate normalized, and the major clinical manifestations of CS subsided, loss of a circadian cortisol rhythm persisted after surgery. Twenty-seven years later, the patient presented again with short stature, severe osteopenia, skeletal deformities, thinning of the skin, and myopathy.

Islet amyloid polypeptide in pancreatic tissue of children with persistent hyperinsulinemic hypoglycemia caused by primary islet hyperplasia and nesidioblastosis.

Islet amyloid is a recognized characteristic finding in insulinoma and secondary islet hyperplasia resulting from severe insulin resistance. Little information is available about the presence of islet amyloid in primary islet hyperplasia (nesidioblastosis) of childhood. Here we report that islet amyloid was not present in 12 children with primary islet hyperplasia associated with hyperinsulinemic hypoglycemia.

Ovarian lesions in Carney complex: clinical genetics and possible predisposition to malignancy.

Carney complex (CNC) is a familial multiple neoplasia and lentiginosis syndrome (OMIM 160980, http://www.ncbi.nlm.nih.gov/omim) with features overlapping those of other multiple endocrine neoplasias and hamartomatoses, Peutz-Jeghers syndrome (PJS) in particular. Although a number of patients with CNC and ovarian tumors have been described in individual patient reports, it is unclear whether ovarian lesions constitute a component of the syndrome or are coincidental events. We investigated 18 women with CNC [age at first evaluation, 31.3+/-12.1 yr (mean +/- SD)] prospectively for the development of ovarian tumors over a period of 35.7+/-30.6 months by physical examination and pelvic ultrasonography. They were compared with 11 women (age at first evaluation, 32.9+/-17 yr) who were enrolled under the same protocol (follow up, 32.3+/-25.1 months) and served as a control group. In addition, a registry of 178 women from among a total of 309 patients with CNC was searched retrospectively for any having ovarian tumors. Seven available histological specimens were rereviewed. None of the CNC patients had ovarian tumors analogous to those of PJS. Two patients with CNC in the prospective group developed ovarian tumors and were operated upon. One had bilateral oophorectomy for asynchronous serous cystadenomas. The second patient had a unilateral serous cystadenoma. Resected tumor tissue from both patients was tested for genetic abnormalities of the chromosomal regions to which CNC genetic loci have been mapped. Both showed genomic amplification of chromosomal region 2p16. An additional 10 patients had at least 1 sonogram positive for ovarian cysts. Only 1 of the patients in the control group was found to have a persistent, simple ovarian cyst by ultrasonography. The registry of 178 CNC patients included 4 who had undergone surgery for ovarian tumors. The diagnoses included endometrioid adenocarcinoma (1 patient) and metastatic mucinous adenocarcinoma (the primary site was probably ovarian; 1 patient). In addition, 7 of 12 patients (58%) with CNC, who died of other causes, had ovarian lesions at autopsy. In conclusion, although the same stromal tumor, large-cell calcifying Sertoli cell tumor, affects the testes in CNC and PJS, we did not find such tumors in a small population of CNC patients that was studied prospectively or a larger group of CNC patients that was studied retrospectively. The results of our study also suggested that women with CNC commonly develop ovarian cysts and may be at risk for ovarian carcinoma. The chromosome 2p16 CNC locus was involved in ovarian pathology with apparent copy number gain, suggesting that at least molecularly there is some involvement of the CNC gene(s) in these lesions. Although ovarian tumors do not seem to be a major manifestation of CNC, sonography of the ovaries may be part of the initial evaluation for this genetic syndrome in women with CNC; follow-up of any identified lesion is recommended because of the possible risk for malignancy.

Thyroid gland 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 that affects endocrine glands, including the pituitary, adrenals, and testes; thyroid gland involvement has not been unequivocally demonstrated. In the present study, the medical records of 12 families with Carney complex (53 affected patients) were reviewed for evidence of thyroid abnormality; 2 patients with thyroid carcinoma (1 papillary and 1 follicular; 3.8%) and 1 with follicular adenoma were identified in 3 unrelated kindreds. Six affected members of these kindreds were then screened for the presence of thyroid disease (familial cases). We also studied 5 patients with the complex who had no affected relatives (sporadic cases). These 11 patients consisted of 5 adults [mean age, 33.2 +/- 9.2 (+/- SD) yr] and 6 children and adolescents (mean age, 13.8 +/- 2.5 yr). All had normal results of physical and biochemical examination of the thyroid gland (total and free T4, T3, and TSH levels). Thyroid ultrasonography showed hypoechoic, cystic, solid, or mixed lesions in 3 of the 5 adults (60%) and 4 of the 6 children (67%). Two patients underwent fine needle aspiration biopsy, which identified follicular lesions. Thyroid gland abnormalities were documented in 5 siblings and 1 parent-child pair. We conclude that thyroid gland pathology is 1) common in patients with Carney complex; 2) includes a spectrum of abnormalities ranging from follicular hyperplasia and/or cystic changes to carcinoma; and 3) is inherited in an autosomal dominant manner, like the other manifestations of the syndrome, it is therefore, a candidate component of the syndrome. Ultrasonography is useful in the detection and clinical follow-up of these lesions.

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.

Synaptophysin immunoreactivity in primary pigmented nodular adrenocortical disease: neuroendocrine properties of tumors associated with Carney complex.

Carney complex (CNC) is characterized by lentiginosis and myxomatosis together with a variety of endocrine, neural crest-derived, and other tumors, including primary pigmented nodular adrenocortical disease (PPNAD). PPNAD is characterized by lipofuscin-containing, autonomously functioning, cortisol-producing nodules surrounded by mostly atrophic adrenocortical and normal adrenomedullary tissue. The nature and origin of the tumors, including the myxomas and PPNAD, are unclear. In this study, seven paraffin-embedded PPNAD tumors, one skin myxoma, and two cell lines (one myxoma and one PPNAD) established from patients with CNC were stained with antisera for synaptophysin (SYN), neuron-specific enolase, chromogranin A, tyrosine hydroxylase, and the neural cell adhesion molecule (NCAM). In addition, one PPNAD specimen and one myxoma were analyzed by electron microscopy. The results showed that chromogranin A and tyrosine hydroxylase stained adrenomedullary tissue, but not the PPNAD nodules or the extranodular adrenal cortex. SYN, neuron-specific enolase, and NCAM also stained the medulla. PPNAD nodules and the PPNAD cell line, but not the extranodular adrenal cortex, stained intensely for SYN. The myxoma cell line, but not normal fibroblasts, stained for SYN and NCAM. Ultrastructural analysis of a PPNAD tumor and a skin myxoma revealed a well developed rough endoplasmic reticulum, prominent mitochondria, and vesicle-like structures dispersed throughout the cytoplasm. We conclude that immunostaining for SYN, a marker protein for neuroendocrine cells, clearly distinguishes PPNAD nodules from surrounding adrenocortical tissue and can be helpful in the detection of small nodules in apparently unaffected cortex. The cells of a cutaneous myxoma were also stained positive by two of the three neuroendocrine markers. Finally, both PPNAD and myxoma cells demonstrated ultrastructural features suggestive of neuroendocrine properties. These results support the previously suggested hypothesis that the genetic mechanism leading to CNC involves genes with a neuroendocrine role.

Carney complex, Peutz-Jeghers syndrome, Cowden disease, and Bannayan-Zonana syndrome share cutaneous and endocrine manifestations, but not genetic loci.

Carney complex (CC), Peutz-Jeghers syndrome (PJS), Cowden disease (CD), and Bannayan-Zonana syndrome (BZS) share clinical features, such as mucocutaneous lentigines and multiple tumors (thyroid, breast, ovarian, and testicular neoplasms), and autosomal dominant inheritance. A genetic locus has been identified for CC on chromosome 2 (2p16), and the genes for PJS, CD, and BZS were recently identified; genetic heterogeneity appears likely in both CC and PJS. The genes for PJS and CD/BZS, STK11/LKB1 and PTEN, respectively, may act as tumor suppressors, because loss of heterozygosity (LOH) of the PJS and CD/BZS loci has been demonstrated in tumors excised from patients with these disorders. We studied 2 families with CC in whom the disease could not be shown to segregate with polymorphic markers from the 2p16 locus. Their members presented with lesions frequently seen in PJS and the other lentiginosis syndromes. We also tested 16 tumors and cell lines established from patients with CC for LOH involving the PJS and CD/BZS loci. DNA was extracted from peripheral blood, tumor cell lines, and tissues and subjected to PCR amplification with primers from microsatellite sequences flanking the STK11/LKB1 and PTEN genes on 19p13 and 10q23, respectively, and a putative PJS locus on 19q13. All loci were excluded as candidates in both families with LOD scores less than 2 and/or by haplotype analysis. LOH for these loci was not present in any of the tumors that were histologically identical to those seen in PJS. The overall rate of LOH for the PJS and CD/BZS loci in tumors from patients with CC was less than 10%. We conclude that despite substantial clinical overlap among CC, PJS, CD, and BZS, LOH for the STK11 and PTEN loci is an infrequent event in CC-related tumors. Linkage analysis excluded the PJS and CD/BZS loci on chromosomes 19 (19p13 and 19q13) and 10 (10q23) from harboring the gene defect(s) responsible for the phenotype in these 2 families.