Extensive lipomatous metaplasia in bilateral macronodular adrenocortical hyperplasia.

OBJECTIVE: We describe a case of macronodular hyperplasia with marked adrenal enlargement in which mature adipose tissue was a significant component. To our knowledge, this condition has not been reported previously.
METHODS: A 42-year-old woman with newly diagnosed Cushing's syndrome underwent endoscopic bilateral adrenalectomy to remove bilateral adrenal masses.
RESULTS: Both adrenal glands displayed features of macronodular hyperplasia with marked adrenal enlargement, and abundant mature adipose tissue was identified in some nodules of both glands.
CONCLUSIONS: Lipomatous metaplasia is histologically demonstrated in a case of macronodular hyperplasia with marked adrenal enlargement. This distinctive change may be secondary to metaplastic transformation of either stromal cells or adrenocortical cells. The presence of lipomatous metaplasia would appear to indicate adrenocortical process, since, to our knowledge, it has never before been described in the adrenal nodule.