Phaeochromocytoma in multiple endocrine neoplasia type 2 A: survey of 100 cases

We report clinical, biochemical, morphological and histological data of phaeochromocytoma in 40 French families and in apparently sporadic cases of multiple endocrine neoplasia (MEN) type 2 A (medullary thyroid carcinoma, phaeochromocytoma, with or without hyperparathyroidism).

This retrospective study was obtained from cases registered by the 'Groupe d'Etudes des Tumeurs à Calcitonine' from 1968 to 1990. We analysed the cases having sufficiently precise data on phaeochromocytoma with Pigas Software.

Characteristics of phaeochromocytoma in 100 patients with MEN 2 A were reviewed. Phaeochromocytoma was bilateral in 51%. The disease was inherited in 94 patients from 40 families (40 probands, 54 relatives), and was apparently sporadic in six.

In this series, diagnostic circumstances were highly suggestive of phaeochromocytoma in 39.8% of the cases, whereas in 43.2%, diagnosis was made through systematic investigations of patients, either before (27.3%) or after (13.6%) thyroidectomy, or after discovery of hyperparathyroidism (2.3%). Fifteen per cent of patients were detected by family screening. Sudden death occurred in 8.9%, malignant phaeochromocytoma in 3%, and ectopic tissue in 4% of the cases. Urinary metanephrines appeared to be the most sensitive screening test. The extent of clinical symptoms was not associated with a particular hormonal pattern. Bilateral adrenalectomy was performed in 60% (in one step in 50%, in two steps in 10%). In these patients, bilateral histological lesions were observed in 92.5%. Simultaneous diagnosis for adrenal and thyroid disease was made in 73.4%, but phaeochromocytoma may be diagnosed before (9.6%) or after (17%) medullary thyroid carcinoma, with an interval greater than 2 years in 25 cases.

Owing to variable clinical symptoms of phaeochromocytoma in these 100 cases of MEN 2 A, systemic biological adrenal assay is required. The search for phaeochromocytoma in medullary thyroid carcinoma (and vice versa) has to be systematically performed, even in apparently sporadic cases. Screening for phaeochromocytoma must be repeated for years, owing to the frequency of bilateral adrenal disease.