Bilateral congenital nasolacrimal duct cyst: an unusual cause of respiratory distress in the neonate.

cular case. Unfortunately we were not able to study the genetics of our patient's tumors or his constitutional genotype. The present case raised a significant diagnostic dilemma. Due to the history of a previously resected meningioma and the recognized tendency of recurrence, and because of its radiographic appearance, the right temporal tumor was originally suspected to be a meningioma. However, unexpectedly, it was associated with intense concentration of MIBG. In view of the rarity of cranial pheochromocytoma metastases we speculated on the possibility of meningioma-associated catecholamine secretion, but this was rejected by the histopathologic findings that were compatible with metastatic pheochromocytoma, as well as by the lack of secretory characteristics in the meningioma tissue. Two previous reports on coexistent meningiomas and pheochromocytomas referred to benign pheochromocytomas [1,2]. To the best of our knowledge, the present case is the only available report of a patient with meningioma associated with malignant (metastatic) pheochromocytoma. Following removal of the right frontotemporal metastasis of pheochromocytoma, a marked decrease in urinary catecholamine excretion was observed; however, urinary catecholamines excretion subsequently increased beyond their preoperative level [Figure B]. Administration of MIBG, used as a pharmacologic vehicle for conveying radioactive iodine to the pheochromocytoma metastases, produced an initial apparently encouraging response, based on an observed decrease in urinary catecholamines and metanephrine excretion after each administration. However, evidence for remission was short-term [Figure B], as post-MIBG scans failed to show regression of the metastases and catecholamine excretion subsequently increased. The discrepancy between the observed fall in catecholamine secretion on the one hand and the consistency of MIBG scans on the other underlines that caution should be applied to the interpretation of urinary catecholamines and metanephrine excretion as markers for monitoring the therapeutic response in patients with malignant pheochromocytoma. References