NONSPORADIC CASES AND UNUSUAL MORPHOLOGICAL FEATURES IN PHEOCHROMOCYTOMA AND PARAGANGLIOMA

Background. - Pheochromocytomas and paragangliomas are well-defined en tities. Some of their nonsporadic associations and unusual morphologic al appearances are not universally appreciated. Design. - We reevaluat ed all adrenal pheochromocytomas and extra-adrenal paragangliomas seen at our institution in the period from 1980 through 1995 for their non sporadic presentation or unusual morphological features and for the pr esence of sustentacular cells. Results. - Among 71 pheochromocytomas a nd paragangliomas in 60 patients, there were seven nonsporadic cases ( 11.5%), including three familial cases, two cases of multiple endocrin e neoplasia 2a syndrome, one case associated with neurofibromatosis ty pe 1, and one case of incomplete Carney's triad. In addition, we saw t wo cases of pheochromocytoma associated with metachronous malignant me lanoma and one case of multicentric paraganglioma in a patient with Ma ffucci's syndrome. Unusual morphological features were as follows: som e degree of coexisting cortical hyperplasia (eight cases), vacuolar de generation of tumor cells (three cases), composite pheochromocytoma (o ne case), presence of pheochromoblasts and calcospherites (one case), melanin pigmentation (two cases), and insular growth pattern (four cas es); the latter was associated with malignant behavior in two cases. S ustentacular cells varied in number but were consistently numerous in all nonsporadic cases. Conclusions. - Nonsporadic cases of pheochromoc ytoma comprise around 10% of all cases in this as in other series. Som e other, less well-recognized associations, eg, with malignant melanom a, may also belong to this group. Unusual morphological features occur in a substantial number of cases and may cause diagnostic problems.