Morphometric analysis of benign and malignant adrenal pheochromocytomas

At present, there are no reliable histologic features that can predict malignancy in adrenal pheochromocytomas other than the documentation of metastases. With the use of computerized interactive morphometry, our aim was to assess nuclei from tissue sections of confirmed cases of benign and malignant pheochromocytomas to determine whether consistent quantitative differences existed between the two. Eight benign cases with at least a 5-year follow-up and nine malignant cases with documented metastases were evaluated. Size distribution plots of the maximum nuclear cord length and of the nuclear area showed a narrow peak for the malignant cases, whereas benign cases showed a right-shifted curve with a wider peak. We concluded that nuclear morphometric analysis of benign and malignant pheochromocytomas yields two distinctive patterns and may be of utility in the assessment of future cases.