Carney-Stratakis Syndrome

Carney-Stratakis syndrome is a recently described familial syndrome characterized by gastrointestinal stromal tumors (GIST) and paragangliomas, often at multiple sites.

Epidemiology

It is a very rare syndrome reported in less than 20 unrelated families to date. It presents at a young age (median age: 19 years) with an apparently equal ratio of male and female patients.

Clinical description

Patients with Carney-Stratakis syndrome have both GIST and paraganglioma. The gastric stromal sarcomas are multifocal and the paragangliomas are multicentric. The clinical spectrum of Carney-Stratakis syndrome varies widely, depending on the localization and the size of the tumors, and may include a palpable mass, dysphagia, abdominal pain, weight loss, hematemesis, melena, obstruction, perforation, cranial nerve palsies, tinnitus and hearing loss. GIST are intramural mesenchymal tumors of the gastrointestinal tract that originate from stem cells with characteristics of the interstitial cells of Cajal (the pacemaker cells which regulate peristalsis in the digestive tract). Paragangliomas are usually benign tumors that occur without clinical evidence of oversecretion and that arise within the sympathetic nervous system from cells of the paraganglia.

Etiology

The vast majority of Carney-Stratakis syndrome cases are due to germline mutations of the succinate dehydrogenase (SDH) subunit genes SDHB, SDHC and SDHD.

Diagnostic methods

Diagnosis is made by clinical and radiologic examination, and confirmed immunohistochemically. Genetic testing to determine if SDH defects may be contributing to tumor growth or recurrence should be offered to pediatric GIST patients.

Differential diagnosis

The main differential diagnosis includes Carney triad.

Genetic counseling

Predisposition to developing these tumors is inherited in an autosomal dominant manner with incomplete penetrance.

Management and treatment

Treatment modalities are surgery, embolization and radiotherapy. Chemotherapy with imatinib mesylate may be helpful for some patients with advanced-stage GIST. Targeting SDH function may potentiallybe useful in treating Carney-Stratakis syndrome patients but, at present, there are no drugs that restore SDH function. Life-long follow-up should be offered to patients with Carney-Stratakis syndrome.