Adrenocortical Carcinoma
A drenocortical carcinoma is a rare, highly aggressive malignancy with an incidence of 0.5 to 2 cases per million per year in the United States with a slight female prepon- derance.1-3 Although it can occur at any age, patients between 30 and 50 years old are most often affected. The proportion of cancers that are endocrinologically functional ranges from 26% to 76%. Most are large with average weight ranging from 510 to 1,210 gm and average diameter from 12 to 16.6 cm. However, size and weight historically have not been reliable parameters of malig- nancy, because tumors less than 50 gm and as small as 3 cm have exhibited malignant behavior.
Tumors are typically composed of yellow-orange to tan nod- ules of variable size intersected by broad fibrous bands with varying degrees of hemorrhage, necrosis and cystic degenera- tion (fig. 1). Histologically tumor cells are arranged in broad trabeculae, narrow elongated columns, nests or solid sheets, often with necrosis (fig. 2). Tumor cells are predominantly lipid depleted and have modest amounts of eosinophilic cytoplasm. Nuclear pleomorphism may be striking but this may also be noted in benign adenomas. Mitotic figures, including atypical forms, are relatively common (fig. 2, inset).
Distinguishing adrenocortical carcinoma from benign adreno- cortical adenoma is challenging due to the considerable overlap of pathological findings between these entities. Definitive criteria for malignancy are locoregional invasion, tumor recurrence and dis- tant metastasis. However, the absence of these findings at diag- nosis does not exclude malignancy and several multiparametric systems have been devised to assist in making this distinction. 1,2 These systems involve the evaluation of parameters such as mi- totic rate, percent of tumor cells exhibiting cytoplasmic eosino- philia, abnormal mitotic figures, necrosis, capsular invasion, in- tratumor mitotic figure variability, anisokaryosis, growth pattern and stromal reaction to tumor. Presently there is no consensus on which system is superior. We find the revised Weiss system useful in clinical practice.1
Of patients younger than 20 years tumors are most likely to occur in those younger than 5 or more than 10 years old, and approximately 80% of tumors are functional.3 In these patients tumors larger than 10.5 cm and greater than 400 gm are statistically likely to have a poor outcome.3 Applying histolog- ical criteria for malignancy in adults to pediatric patients cre- ates a significant group of pathologically malignant but clini- cally benign tumors. Nine histological criteria for malignancy in pediatric adrenocortical tumors have been proposed, and the probability of clinically malignant behavior of a tumor in- creases with the number of criteria that are met. Separation of patients into 3 clinical categories has been suggested with 2 or fewer criteria met-good clinical outcome, 3 criteria-indeter- minate for malignancy and 4 or more criteria-malignant.3
Camil J. Chouairy Department of Pathology St. George Hospital Beirut, Lebanon and
Fadi Abdul-Karim and Gregory T. MacLennan Department of Pathology University Hospitals of Cleveland Case Western Reserve University Cleveland, Ohio
1. Aubert S, Wacrenier A, Leroy X, Devos P, Carnaille B, Proye C et al: Weiss system revisited: a clinicopathologic and immu- nohistochemical study of 49 adrenocortical tumors. Am J Surg Pathol 2002; 26: 1612.
2. Blanes A and Diaz-Cano SJ: Histological criteria for adrenocor- tical proliferative lesions: value of mitotic figure variability. Am J Clin Pathol 2007; 127: 398.
3. Wieneke JA, Thompson LD and Heffess CS: Adrenal cortical neoplasms in the pediatric population: a clinicopathologic and immunophenotypic analysis of 83 patients. Am J Surg Pathol 2003; 27: 867.
Vol. 179, 323, January 2008 Printed in U.S.A. DOI:10.1016/j.juro.2007.10.007