Carney triad versus Carney Stratakis syndrome: two cases which illustrate the difficulty in distinguishing between these conditions in individual patients.

Carney triad is a usually sporadic association of pulmonary chondroma, gastrointestinal stromal tumours, and paraganglioma. The majority of patients have two of these tumours, the gastric and pulmonary tumours being the most common combination. Carney Stratakis syndrome is an association of familial paraganglioma and gastric stromal sarcoma and it is considered to be a distinct condition from Carney triad as it is dominantly inherited and not associated with pulmonary chondroma. We report two unrelated patients each with two components of Carney triad. A pathological mutation in succinate dehydrogenase subunit B gene was identified in one and a variant in the same gene was identified in the other. This report demonstrates the difficulty in distinguishing between Carney triad and Carney Stratakis syndrome due to the rarity of the individual components. The fact that most patients with Carney triad have only two components of the Triad, and the long interval often seen between the occurrence of the first and the second component makes it difficult to differentiate confidently between the two conditions. Molecular information should improve the diagnosis of Carney triad.