Cytologic features of malignant cystic pheochromocytoma: a case report.

Background Image-guided four needle aspiration (FNA) biopsy of deep-seated lesions (e.g. retroperitoneal) has aided preoperative diagnosis and treatment planning. Fine needle aspiraion biopsy of pheochromocytomas traditionally has been contraindicated by many authors because of possible hypertensive crisis and fatal hemorrhage. Cytologic features are described for a malignant pheochromocytoma (greater percentage of smaller cells and absence of hyaline globules) with extensive cystic degeneration that was later confirmed by histopathologic, immunohistochemical and ultrastructural studies. Case An elderly man was diagnosed with renal cell carcinoma based on clinical examination and ultrasonography. FNA performed on the mass revealed interesting features of pheochromocytoma with an abundance of small cells. Conclusion The cytopathologist should be aware of the cytologic features of pheochromocytoma so as to detect a clinically unsuspected lesion. An increased percentage of smaller cells may be indicative of aggressive tumors.