Laboratory Studies
- Complete blood count
- Glucose/electrolytes
- Erythrocyte sedimentation rate
- Thyroxine/thyroid stimulating hormone
- Adrenocorticotropic hormone
- Growth hormone
Imaging Studies
Echocardiography is the investigation of choice to define cardiac involvement in the Carney complex.[6]
See the image below.
Transthoracic echocardiogram of a left atrial myxoma in an individual with Carney complex. A 42-year-old woman with a history of facial spotty pigmentation and cutaneous myxomas presented for annual surveillance echocardiography. Findings from previous echocardiograms were normal. Echocardiography now revealed a 1.0 X 1.3 cm mass (arrow) in the left atrium (LA) arising from the interatrial septum above the mitral valve. No prolapse was seen into the left ventricle (LV). Histopathology upon surgical excision demonstrated that the lesion was a myxoma. Occasionally, evidence of myxomas may be in more than one cavity.
Echocardiography also defines the presence of associated valvular involvement.
Left atrial myxomas may prolapse through the mitral valve orifice, creating functional mitral stenosis, or may produce progressive valve leaflet damage, leading to mitral insufficiency.
Echocardiography is useful for follow-up of patients after surgical removal of the tumor to detect recurrence of myxomas.
Transesophageal echocardiography reaches a sensitivity of 100%. It is useful to define the precise anatomical relationships of small tumors or to detect the presence of multiple cardiac myxomas.
Body computed tomography scan or MRI may be appropriate to exclude extracardiac thoracic, abdominal, or paraspinal tumors.
Testicular ultrasonography may be used to exclude testicular tumors.
Other Tests
ECG
No specific electrocardiographic features of the Carney complex exist. The ECG findings may reflect the presence of left atrial enlargement or pulmonary hypertension.
Genetic evaluation [7]
Patients thought to have Carney complex should be evaluated by a cardiologist/geneticist with experience in the management of inherited cardiovascular disease.
Referral to an endocrinologist may be appropriate if endocrinological problems are suggested by symptoms or laboratory studies
The initial step in the workup of these patients is the ascertainment of a detailed family history to establish if the patient's disease represents a new mutation or is part of a familial syndrome. Recent studies have shown that linkage analysis of extended families can provide diagnostic information for individuals with equivocal findings; however, these techniques remain research tools that generally are not available clinically. Furthermore, mutational analysis of the PRKAR1A gene may be a useful adjunctive diagnostic test. In the presence of a family history of arthrogryposis, testing for mutation of MYH8 may be appropriate as well. However, such DNA-based testing currently remains the province of research laboratories (see GeneTests).
Procedures
Cardiac catheterization may be indicated on an individual basis prior to surgical resection if coexisting coronary artery disease is a possibility.
Histologic Findings
Myxomas have a typical histologic appearance of small stellate cells against a bland proteoglycan background.
Basson CT, MacRae CA, Korf B, Merliss A. Genetic heterogeneity of familial atrial myxoma syndromes (Carney complex). Am J Cardiol. Apr 1 1997;79(7):994-5. [Medline].
Stratakis CA, Carney JA, Lin JP, et al. Carney complex, a familial multiple neoplasia and lentiginosis syndrome. Analysis of 11 kindreds and linkage to the short arm of chromosome 2. J Clin Invest. Feb 1 1996;97(3):699-705. [Medline].
Casey M, Mah C, Merliss AD, et al. Identification of a novel genetic locus for familial cardiac myxomas and Carney complex. Circulation. Dec 8 1998;98(23):2560-6. [Medline].
Casey M, Vaughan CJ, He J, et al. Mutations in the protein kinase A R1alpha regulatory subunit cause familial cardiac myxomas and Carney complex. J Clin Invest. Sep 2000;106(5):R31-8. [Medline].
Veugelers M, Bressan M, McDermott DA, Weremowicz S, Morton CC, Mabry CC, et al. Mutation of perinatal myosin heavy chain associated with a Carney complex variant. N Engl J Med. Jul 29 2004;351(5):460-9. [Medline].
Reynen K. Cardiac myxomas. N Engl J Med. Dec 14 1995;333(24):1610-7. [Medline].
Goldstein MM, Casey M, Carney JA, Basson CT. Molecular genetic diagnosis of the familial myxoma syndrome (Carney complex). Am J Med Genet. Sep 3 1999;86(1):62-5. [Medline].
Carney JA, Gordon H, Carpenter PC, et al. The complex of myxomas, spotty pigmentation, and endocrine overactivity. Medicine (Baltimore). Jul 1985;64(4):270-83. [Medline].
Kanda T, Umeyama S, Sasaki A, et al. Interleukin-6 and cardiac myxoma. Am J Cardiol. Nov 1 1994;74(9):965-7. [Medline].
Veugelers M, Wilkes D, Burton K, et al. Comparative PRKAR1A genotype-phenotype analyses in humans with Carney complex and prkar1a haploinsufficient mice. Proc Natl Acad Sci U S A. Sep 28 2004;101(39):14222-7.
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