Unexpected histological findings of lesions diagnosed in the adrenal region in a series of 420 patients submitted to adrenal surgery. Review of our experience.

INTRODUCTION: The incidence of adrenal incidentalomas is reported to be up to 30% in the current literature; nevertheless, in some patients undergoing surgery, a final diagnosis of non-adrenal origin of the mass is performed. In this paper we present our experience of 13 patients with unexpected histological findings of lesions diagnosed in the adrenal region. PATIENTS AND METHODS: From June 1986 to December 2004, 420 patients underwent adrenalectomy in our Department. Since the introduction of videolaparoscopic technique in 1993, 228 adrenalectomies have been performed videolaparoscopically. Pre-operative diagnosis was: incidentaloma (34.0% of patients), Conn's adenoma (29.0%), Cushing's adenoma (13.9%), pheochromocytoma (8.8%), suspicious metastasis (7.3%), Cushing's disease (6.0%), other (1.0%).
RESULTS: Final histology revealed an unexpected diagnosis of non-adrenal origin of the mass in 13 patients (3.1%). Histology demonstrated a benign neurogenic tumor in 10 patients. In the other 3 patients diagnosis was respectively of lymphnode, hemangioma and a gastric metastasis of melanoma. Five patients out of 7 had a successful laparoscopic resection of the lesion. Mean operative time in this group was higher compared to laparoscopic resection for adrenal lesion (95.3 min vs 73.2 min).
CONCLUSION: A small percentage of our patients (3.1%) demonstrated unexpected findings of the lesion pre-operatively misinterpreted as an adrenal mass. Despite a complete pre-operative assessment, adrenal lesions might reveal a different origin, increasing the surgical challenge as well as the morbidity for the patient.