Endocrine Abstracts

Case: A GP with autoimmune hypothyroidism presented with a phaeochromocytoma during labour at the age of 36 y. A left adrenalectomy confirmed the diagnosis and a basal cell carcinoma was also removed. She had a history of Dupuytren's lesions of both soles and palms starting in her teenage years and multiple keratosis. There was no family history of any endocrine or skin disorder. At 41y, a benign breast lump was removed and also a gastrointestinal spindle cell stromal tumour (GIST). CXR was normal.

The GIST showed moderate staining for CD34 and muscle specific actin and strong positivity for CD117 (c-KIT) and a diagnosis of Carney triad variant was made. Currently, her urinary catecholamine excretion is elevated and she has a further GIST at the gastroesophageal junction. Genetic studies for MEN did not reveal a mutation.

Discussion: In 1977, Carney et al. reported association between gastric leiomyosarcoma, functioning extra-adrenal paraganglioma and pulmonary chondroma described as Carney triad. Other features were added subsequently. 85% of the patients are females, the majority of whom are diagnosed before the age of 30. Only 2 of the 3 features are required for the diagnosis, paragangliomas being the least frequent component. Familial paraganglioma and gastric stromal sarcoma is now being recognised as a distinct syndrome (Carney dyad), although there is overlap of components between it and the original Carney triad. The relative frequency of the shared tumours in the two conditions is reversed: paraganglioma predominates in this syndrome whereas gastric stromal tumour predominates in the original Carney triad. Genetic loci for familial paragangliomas have been mapped to 11q22-23, 11q13.1 and 1q21-23. In addition, germline mutations in three of the succinate dehydrogenase (SDH, mitochondrial complex II) subunits, SDHC, SDHD and SDHB have been identified in subgroup of patients with familial paraganglioma and familial pheochromocytoma. Genetic analysis of tissues from the patient is awaited.