Carney complex

Carney complex
Lentiginosis, cardiac myxoma and skin myxoma: Courcoutsakis NA, Tatsi C, Patrona · CC BY 4.0 · source
Name	Carney complex
Specialty	Endocrinology, Dermatology, Cardiology, Genetics
Symptoms	Cardiac myxomas, spotty skin pigmentation, endocrine tumors, schwannomas
Complications	Stroke, heart failure, endocrine dysfunction, malignancy
Onset	Childhood to adulthood
Causes	PRKAR1A mutation, CNC2 locus
Diagnosis	Clinical criteria, genetic testing, imaging, histopathology
Treatment	Surgical resection, medical therapy, surveillance
Frequency	Rare

Carney complex is a rare, autosomal dominant multiple neoplasia syndrome characterized by cardiac myxomas, spotty skin pigmentation, and endocrine overactivity. First described in case series from large referral centers and historical review articles, the condition links clinical endocrinology, clinical genetics, cardiothoracic surgery, dermatology, and oncology. Patients often present to clinics for cardiology, dermatology, endocrinology, or neurosurgery evaluation and require multidisciplinary care from institutions and specialists experienced with hereditary tumor syndromes.

Introduction

Carney complex was delineated through case reports and cohort studies originating from academic centers such as the Mayo Clinic, Johns Hopkins Hospital, and Brigham and Women's Hospital, and has been discussed at meetings of the Endocrine Society, American Heart Association, and European Society of Cardiology. Classic manifestations include cardiac myxomas that can embolize leading to stroke or require urgent resection at centers like Cleveland Clinic and Massachusetts General Hospital, cutaneous lentigines often evaluated by dermatologists at university hospitals, and endocrine tumors including pituitary adenomas and primary pigmented nodular adrenocortical disease (PPNAD) managed by endocrine surgeons and pediatric endocrinology units. The syndrome is managed through genetic counseling by clinical genetics units, molecular diagnostics at reference laboratories, and long-term surveillance protocols developed by expert panels and guideline committees.

Genetics and Pathophysiology

Germline inactivating mutations in PRKAR1A on chromosome 17 were identified by teams at research institutions collaborating with geneticists from the National Institutes of Health and international consortia. PRKAR1A encodes a regulatory subunit of protein kinase A, implicating cyclic AMP signaling pathways studied in basic science laboratories and cancer biology departments at universities such as Harvard, Stanford, and Cambridge. Loss of PRKAR1A function leads to dysregulated cell proliferation in tissues including cardiac myocardium, adrenal cortex, and skin, paralleling molecular pathways investigated in studies from the Max Planck Institute and Wellcome Trust Sanger Institute. A second locus, sometimes referred to as CNC2, has been mapped by linkage analyses involving collaborative groups across Europe, Australia, and North America, with tumor suppressor mechanisms explored in laboratories at Cold Spring Harbor Laboratory and Institut Curie. Somatic second-hit mechanisms follow Knudson’s two-hit hypothesis as demonstrated in tumor sequencing projects and pathology departments affiliated with Memorial Sloan Kettering Cancer Center.

Clinical Features and Presentation

Patients may present with cardiac manifestations documented in cardiology case series from the European Heart Journal and Journal of Thoracic and Cardiovascular Surgery, including intracardiac myxomas that mimic presentations seen in thromboembolic stroke cases at neurological centers like Mayo Clinic Jacksonville. Cutaneous findings such as lentigines, blue nevi, and myxomas of the eyelid are described in dermatology reports from clinics at Johns Hopkins and University College London. Endocrine features include Cushing syndrome from PPNAD, pituitary growth hormone–secreting adenomas leading to acromegaly reported in endocrine journals, and thyroid nodules or carcinoma discussed in endocrine oncology symposia at institutions like MD Anderson Cancer Center. Additional findings include psammomatous melanotic schwannomas described in neuropathology case series and testicular tumors reported in urology departments at university hospitals. Presentation can span pediatric populations seen at children’s hospitals such as Great Ormond Street Hospital to adult oncology clinics at Royal Marsden Hospital.

Diagnosis

Diagnosis integrates clinical criteria developed by expert consensus groups, genetic testing provided by clinical molecular laboratories accredited by agencies such as College of American Pathologists and European Molecular Genetics Quality Network, and multimodality imaging including transthoracic and transesophageal echocardiography performed in echo labs at tertiary centers. Magnetic resonance imaging and computed tomography protocols used in neuroradiology and thoracic radiology departments help localize myxomas and schwannomas; adrenal imaging and adrenal venous sampling are utilized by endocrine surgery units. Histopathologic confirmation is conducted by pathology departments with expertise in soft tissue tumors and endocrine neoplasia at institutions like Johns Hopkins, Stanford, and University of California centers. Differential diagnosis includes syndromes such as multiple endocrine neoplasia types discussed in Endocrine Society guidelines and other familial tumor syndromes characterized by dermatologic and cardiac features.

Management and Treatment

Management is multidisciplinary: cardiothoracic surgeons at high-volume centers perform resection of cardiac myxomas with perioperative care coordinated by cardiovascular anesthesiology and intensive care units. Endocrine tumors are managed by endocrine surgeons and medical endocrinologists using approaches described in clinical practice guidelines from societies such as the Endocrine Society and European Society of Endocrinology, including bilateral adrenalectomy for refractory Cushing syndrome in selected cases and transsphenoidal surgery for pituitary adenomas offered at pituitary centers of excellence. Dermatologic lesions are treated by dermatologic surgeons and dermatopathologists, and schwannomas may require neurosurgical resection in tertiary neurosurgery centers. Genetic counseling and cascade testing are provided by clinical genetics services and patient advocacy organizations, with psychosocial support from hospital social work departments and patient support groups affiliated with rare disease networks.

Prognosis and Surveillance

Prognosis depends on tumor burden, recurrence risk, and complications such as embolic events or endocrine failure; outcomes are reported in long-term follow-up studies from referral centers and registries coordinated by academic consortia. Lifelong surveillance protocols recommended by expert panels include periodic echocardiography, endocrine assessment with biochemical testing at endocrine laboratories, dermatologic examinations at academic dermatology clinics, and targeted imaging coordinated by multidisciplinary tumor boards. Surveillance strategies and outcome data are informed by registries maintained at university health systems, rare disease networks, and national health institutes to refine screening intervals and optimize morbidity and mortality.

Category:Rare genetic syndromes