Carney syndrome
CARNEY SYNDROME (CARNEY TRIAD):
Carney syndrome (Carney Triad) was originally proposed to describe cases involving the coexistence of several neoplasms, including: gastric epithelioid leiomyosarcoma, pulmonary chondroma, and extra-adrenal paraganglioma.(1)
Recent advances in molecular biology have demonstrated that the so-called gastric epithelioid leiomyosarcomas, in fact, represent gastrointestinal stromal tumours (GISTs).(2) This distinction is important amongst physicians. Pathologists, in addition to examining the conventional morphology of the tumour using a microscope, will use a special diagnostic technique called immunohistochemistry to detect the expression of the molecule CD117 (c-kit) to confirm the diagnosis. Clinicians, in turn, typically treat these tumours with a drug that specifically targets mutations in c-kit, called Gleevec; however, there is limited evidence to suggest that GISTs in Carney Syndrome lack c-kit mutations (i.e., they are wild-type), hence may prove unresponsive to this medication.(3)
Occasionally Carney syndrome is erroneously used by physicians to describe Carney Complex, or vice versa;(4,5,6) however, these terms represent two entirely distinct entities. Carney Complex, simply stated, describes a multiple neoplasia syndrome that is generally characterized by myxomatous neoplasms (cardiac, endocrine, cutaneous and neural), and a host of pigmented lesions of the skin and mucosae, including the rarely occurring epitheloid blue naevus.(7,8)
Differential Diagnosis
Carney syndrome must be differentiated from other diseases causing multiple polyps, such as:
| Diseases | History and Symptoms | Physical Examination | Laboratory Findings | Other Findings | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Abdominal Pain | Rectal Bleeding | Fatigue | Abdominal Tenderness | Hyperpigmentation | Anemia | Gene(s) | Gastrointestinal Tumors | Cancers | ||
| Carney Syndrome | – | – | – | – | – | |||||
| Familial Adenomatous Polyposis | + | + | + | +/– | – | + |
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| Peutz–Jeghers syndrome | + | + | + | + | + | + |
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| Juvenile Polyposis Syndrome | + | + | – | – | – |
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| Cowden Syndrome | – | – | – | – | – |
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| Hereditary Non–Polyposis Colon Cancer | – | + | + | +/– | – | + | ||||
REFERENCES
1. Carney JA. The triad of gastric epithelioid leiomyosarcoma, pulmonary chondroma, and functioning extra-adrenal paraganglioma: a five-year review. Medicine (Baltimore). 1983;62(3): 159-169.
2. Boccon-Gibod L, Boman F, Boudjemaa S, Fabre M, Leverger G, Carney AJ. Separate occurrence of extra-adrenal paraganglioma and gastrointestinal stromal tumor in monozygotic twins: probable familial Carney syndrome. Pediatr Dev Pathol. 2004;7(4):380-4.
3. Diment J, Tamborini E, Casali P, Gronchi A, Carney JA, Colecchia M. Carney triad: case report and molecular analysis of gastric tumor. Hum Pathol. 2005;36(1):112-6.
4. http://www.emedicine.com/derm/topic805.htm
5. Rosai J. Surgical Pathology, 9th Ed. Mosby: China. 2004; p.117.
6. Nwokoro NA, Korytkowski MT, Rose S, Gorin MB, Penles Stadler M, Witchel SF, Mulvihill JJ. Spectrum of malignancy and premalignancy in Carney syndrome. Am J Med Genet. 1997;73(4):369-77.
7. Carney JA, Gordon H, Carpenter PC, Shenoy BV, Go VL. The complex of myxomas, spotty pigmentation, and endocrine overactivity. Medicine (Baltimore). 1985;64(4):270-83.
8. Iglesias C, Torrelo A, Colmenero I, Mediero IG, Zambrano A, Requenca L. Isolated multiple congential epithelioid blue naevus. British Journal of Dermatology 2005;152:391-393.