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Biomedical subjects

John A Lopez

Publications and source records attributed to John A Lopez.

2 recordsLinked to original sources

CSF shunt failure with stable normal ventricular size.

OBJECTIVE: The purpose of this study was to review the clinical features of a group of patients in whom ventricular enlargement was not a manifestation of prolonged CSF shunt obstruction. RESULTS: Twelve patients who had prolonged symptoms consistent with CSF shunt failure and stable normal ventricular size were demonstrated at the time of surgery to have obstruction of their CSF shunts. CONCLUSION: Ventricular enlargement is a common but not sine qua non indicator of CSF shunt failure, even after weeks or months of elevated intracranial pressure, and therefore cannot be relied upon for the diagnosis of CSF shunt failure. Although an increase in ventricular size is usually seen relatively early in the course of shunt malfunction, stable normal ventricular size in patients with symptoms and signs that are consistent with shunt failure can delay the diagnosis with potentially serious adverse consequences.

Adolescent↗

Silent corticotroph adenomas: further clinical and pathological observations.

Adrenocorticotroph cell pituitary adenomas immunoreactive for adrenocorticotropic hormone (ACTH) but unassociated with preoperative signs of hypercortisolism constitute between 6% and 43% of all ACTH adenomas. Few large series have been published. At our referral center for pituitary diseases, we have encountered 12 patients with silent ACTH adenomas, none of whom exhibited definite clinical features of hypercortisolism preoperatively. Two patients presented with apoplexy, and in 2 patients preoperative neuroimaging studies mimicked craniopharyngioma. Pathological examination revealed 8 adenomas with variably basophilic cytoplasm (type I, including 1 each with coarse basophilic granules and Crooke's hyaline change) and 4 with predominantly chromophobic cytoplasm (type II). Diffuse versus patchy (30% to 50% of cells) immunostaining best distinguished these 2 types; calcitonin staining was focal or negative in both. Two patients had unexpected postoperative courses consistent with acute cortisol insufficiency; 1 patient suffered from a severe flu-like illness, and the other had dizziness and was found to have a serum cortisol level of < 1.0 microg/dL. Both patients improved after cortisol replacement followed by a slow taper. Another patient developed 2 separate pituitary adenomas, a silent ACTH adenoma followed by a pure prolactinoma resected months later. Clonality studies demonstrated that the 2 tumors had arisen from different clonal populations. These cases offer additional insights into clinical, neuroimaging, histological, and biological features of silent ACTH adenomas. Because 2 of these patients seemed to require postoperative cortisol supplementation that otherwise would not have been given, clinicians should be notified about ACTH immunostaining in adenomas from patients without preoperative diagnoses of Cushing's disease, to optimize postoperative care.

Adenoma↗