Scintigraphic patterns of adrenocortical carcinoma: morpho-functional correlates.

OBJECTIVE: Adrenocortical scintigraphy has demonstrated clinical utility in the morpho-functional characterization of adrenal tumors. The aim of this study was to identify possible relationships between the scintigraphic pattern and endocrine and/or morphological data in a series of adrenocortical carcinomas. DESIGN AND METHODS: Twenty-one patients with adrenocortical carcinoma (11 nonfunctioning and 10 hormone-secreting) were investigated with 75Se-methyl-nor-cholesterol scintigraphy. Clinical, hormonal, radiological, and pathological data were analyzed. RESULTS: The adrenal mass showed no radiocholesterol uptake in 18 cases (11 nonfunctioning and 7 functioning lesions). Contralateral normal adrenal gland was visualized in all patients with nonfunctioning tumors, whereas classic bilateral nonvisualization was observed in the 7 cases with hyperfunctioning masses. Three patients with cortisol-producing carcinomas showed radiotracer uptake by the mass, without visualization of the contralateral gland. At histology, the tumors were shown to be undifferentiated adrenocortical carcinomas; they had an aggressive clinical behavior. CONCLUSIONS: Radiocholesterol scintigraphy has an important role in diagnosing adrenocortical carcinomas, which typically are not visualized. However, 30% of hypersecreting adrenocortical carcinomas show an atypical increased tracer uptake, not predictive of the biochemical and histological features of the tumor.