Progressive brainstem compression in an infant with neurocutaneous melanosis and Dandy-Walker complex following ventriculoperitoneal shunt placement for hydrocephalus. Case report.

Neurocutaneous melanosis (NM) coexisting with the Dandy-Walker complex (DWC) is a rare condition, with fewer than 15 cases reported in the literature. The authors present a case of an infant with NM and DWC suffering from progressive brainstem compression following ventriculoperitoneal (VP) shunt placement for hydrocephalus. This 1-year-old boy with congenital melanocytic nevi had met normal developmental milestones until the age of 11 months, when he began regressing in ambulation and language function. Intractable vomiting had developed 1 week later. Magnetic resonance (MR) imaging of the brain revealed DWC with hydrocephalus, and spinal MR images demonstrated a proliferative process within the meninges, consistent with NM. The patient underwent right frontal VP shunt placement resulting in immediate symptom relief, but 3 weeks later became irritable, increasingly lethargic, unable to pull to stand, and unable to tolerate solid food without choking. Due to these symptoms and intractable vomiting, the patient presented to the authors' institution. Brain MR imaging revealed a new-onset diffuse cystic process with anterior and posterior brainstem compression, marked kinking of the cervicomedullary junction, melanocyte pigmentation of the left temporal lobe, diffuse leptomeningeal enhancement, and no evidence of hydrocephalus. Consistent with these imaging findings, the degree of brainstem involvement upon gross visualization predictably deterred resection attempts beyond those necessary for biopsy. Pathological examination revealed diffuse melanocytosis, and the family decided not to pursue aggressive measures postoperatively. This report indicates the potential for rapid intracranial manifestation of diffuse melanocytosis in NM patients. Although the prognosis is poor, early neurosurgical involvement in these patients may provide tissue diagnosis and the potential for decompression if the process is caught early in its course.

Peroxidase activity within circulating neutrophils correlates with pulmonary phenotype in cystic fibrosis.

Excess neutrophils are present in the airways of patients with cystic fibrosis (CF). Myeloperoxidase (MPO) activity of acid extracts of sputum is directly correlated with airflow obstruction in CF patients. We hypothesized that the sputum MPO was derived from the MPO of neutrophils that entered the airways from the circulation. Active MPO without protease activity injures airways. If MPO activity from circulating neutrophils that emigrate into the airways of these patients causes increased airway epithelial permeability and mucus-gland secretion, then (1) those patients with greater MPO activity per circulating neutrophil would be more likely to produce sputum and (2) the MPO activity per circulating neutrophil would positively correlate with airflow obstruction. We determined the MPO activity for both circulating and sputum neutrophils. Spirometry and respiratory cultures were obtained simultaneously with blood and sputum samples. CF patients with more MPO activity within their circulating neutrophils were more likely to produce sputum ( P =.001, chi 2 test), and the MPO activity per circulating neutrophil was positively correlated with airflow obstruction as measured on the basis of the ratio of 1-second forced expiratory volume to forced vital capacity ( P <. 03, Kruskal-Wallace test). These associations were independent of age, sex, the results of respiratory-tract culture, or protease activity in the circulating neutrophils. MPO activity in circulating neutrophils from CF patients homozygotic for the deletion of phenylalanine at position 508 in the CF transmembrane regulator protein is directly related to the severity of these patients' pulmonary disease. Our results are consistent with the hypothesis that circulating neutrophils deliver active MPO to the airway, producing airway injury and airflow obstruction in homozygotic delF508 CF patients.