Unusual adrenal cortical tumor of unknown biologic potential: a nodule in a nodule in a nodule.

Adrenocortical tumors are uncommon neoplasms in childhood. Most pediatric adrenal tumors are virilizing and carcinomas are more common than adenomas. Recent molecular data suggest an adenoma-to-carcinoma progression sequence in adrenal cortical neoplasms. We report a case of a 5-year-old boy who presented with virilizing symptoms secondary to an adrenal tumor that was resected laparoscopically. The bulk of the tumor was a large, yellow mass with typical features of an adrenal cortical adenoma. In the center was a well-circumscribed tan-brown nodule that was distinct from the adenoma and had oncocytic features. A third minute focus (3.0 mm) was noted that was not circumscribed or encapsulated, but showed marked pleomorphism and abundant mitoses, including atypical forms and increased Ki67 compared with the outer 2 nodules. Molecular analysis to assess the clonality and mutation rates of the 3 distinct areas showed only 2 genetic loci with allelic imbalances.