[Pheochromocytomas as adrenal gland incidentalomas]

Abstract

Adrenal incidentalomas are a heterogeneous group of pathological entities, including benign or malignant adrenocortical or medullary tumors, hormonally active or inactive lesions, which are identified incidentally during the examination of nonadrenal-related abdominal complaints. About 1.5% to 23% of adrenal incidentalomas are pheochromocytomas. Composite pheochromocytoma is a rare tumour of adrenal medulla with divergente clinical course. This type of pheochromocytoma is designated "composite" or "mixed," depending on whether pheochromocytoma and nonpheochromocytoma components show the same embryologic origin. Nonpheochromocytoma components found in the composite pheochromocytoma include ganglioneuroma, ganglioneuroblastoma, neuroblastoma, and malignant schwannoma. The biologic behavior of composite pheochromocytomas may be as difficult to predict as more traditional pheochromocytomas; based on the number of cases reported to date the presence of areas resembling ganglioneuroblastoma or neuroblastoma does not necessary indicate a poor prognosis. Some may behave in a malignant fashion with metastasis by a component of the tumour which has neural features. Pheochromocytomas and paragangliomas are well-defined entities. Some of their nonsporadic associations and unusual morphological appearances are not universally appreciated. We report on a rare association of left adrenal CP, with typical right adrenal phochromocytoma and retroperitoneal paraganglioma, and a review of literature. We analyzed the clinical and immunohistochemical features in a 24-year-old woman with composite pheochromocytoma localized in the left adrenal gland and associated with blood pressure of 200/140 mmHg. Abdominal computed tomography and 131-J MIBG revealed a 65 x 60 mm mass in the right adrenal gland, but no revealed 45 x 40 mm retroperitoneal mass and 20 x 20 mm mass in the left adrenal region. Serum and urinary adrenaline levels were high, and catecholamine levels in the blood sample of the selective adrenal vein, were also high. Bilateral adrenalectomy and retroperitoneal mass were surgically removed without complications. Clinical symptoms were absent 6 years after surgery. After surgery the patient gave birth to two healthy babies. Immunohistochemical analyses revealed that tumour cells of right adrenal pheochromocytoma and retroperitoneal paraganglioma were strongly positive for neurone specific enolase, synaptophisin and chromogranin A. The left adrenal tumour showed pheochromocytoma, ganglioneuroma and neuroblastoma components. Immunoreactivity of this tumour added several features to the wide immunohistochemical spectrum. This case demonstrates the indolent behavior of sporadic-type CP and retroperitoneal paraganglioma in an adult patient. Unusual morphological features of CP occur in a substantial number of cases and may cause diagnostic problems.