Acanthamoeba castellani encephalitis following partially mismatched related donor peripheral stem cell transplantation.

We describe a case of Acanthamoeba encephalitis in a 45-year-old Caucasian male with acute myelogenous leukemia, who was 140 days status post partially mismatched related donor peripheral blood stem cell transplant. The patient had been transplanted with a highly T-cell-depleted graft, and was not taking any immunosuppressive drugs, and had no history of graft-versus-host disease. He complained of nausea, vomiting, and occasional episodes of confusion; he also had a chronic cough since transplantation. Physical examination was unremarkable except for orthostatic hypotension. Neurologic examination was within normal limits. Laboratory values including electrolytes, white blood cells and platelet counts were normal. Computed tomographic scan of the brain showed a pansinusitis and a hyperdense lesion along the corona radiata suggestive of a fungal abscess. Magnetic resonance imaging showed multifocal areas with mass effect in the posterior fossa and parietal and occipital lobes. The patient had worsening respiratory failure and died three days after admission. At autopsy, specific immunofluorescent staining identified Acanthamoeba castellani in the brain and lungs.

Sonographic appearance of aggressive angiomyxoma of the scrotum.

Aggressive angiomyxoma (AAM) is a rare, locally infiltrative tumor that occurs almost exclusively in the pelvic and perineal regions of women of childbearing age. We report the unusual case of a 26-year-old man with an AAM presenting as a slowly enlarging scrotal mass. Gray-scale scrotal sonography demonstrated a well-demarcated, hypoechoic, extratesticular, extraepididymal mass with multiple thin, echogenic internal septa. The mass arose inferior to the left testicle and displaced the testicle cephalad. Color Doppler sonography revealed surrounding vascularity but no Doppler signals within the mass. The testicles and epididymides demonstrated normal echogenicity and vascularity. Histologic examination of the excised mass revealed a well-demarcated, nonencapsulated lesion composed of spindle-shaped cells in a myxoid background with a prominent vascular component.

Pediatric chordoid glioma with chondroid metaplasia.

Chordoid gliomas are uncommon primary brain tumors that arise in the region of the third ventricle. Reports of this entity to date have been limited to adults. We present a case of a chordoid glioma arising in the hypothalamic/third ventricle region of a 12-year-old male who presented with visual symptoms. The neoplasm consisted of cords and clusters of well-differentiated, spindled-to-rounded cells containing abundant eosinophilic cytoplasm within a prominent mucinous matrix. Unlike other chordoid gliomas, this lesion contained islands and sheets showing cartilaginous differentiation intermixed with the glial component. A graded transition between neoplastic glial and chondroid regions was evident, and cells in both regions were strongly immunoreactive for GFAP and S-100. Cartilaginous metaplasia is infrequent in gliomas, but occurs most often in pediatric neoplasms of the midline such as this chordoid glioma. Thus, chondroid metaplasia represents an unusual histopathologic feature of chordoid glioma-in this case, presenting in a child.

Extensive leptomeningeal and intraparenchymatous spinal cord neurosarcoidosis.

This case of neurosarcoidosis of the spinal cord involved several meningeal areas and spinal cord levels. It appears to be the tenth autopsy-documented case of neurosarcoidosis of the spinal cord, though the patient had more extensive spinal cord disease than has been previously reported.

Chordoid glioma: a novel tumor of the third ventricle.

Chordoid glioma of the third ventricle is a recently characterized primary neoplasm of the central nervous system. We present a case and discuss the pathologic and radiologic features. We are aware of only 16 other cases documented in the world literature. This radiologic-pathologic correlation alerts pathologists and radiologists to recognize chordoid glioma as a distinct clinicopathologic entity restricted to the third ventricular area of adult patients.

Intraductal carcinoma (carcinoma in situ) of the pancreas with microinvasion.

We report a case of predominantly intraductal carcinoma of the pancreas with microscopic foci of invasive carcinoma in a patient with chronic pancreatitis. In this article, we discuss the pathologic and prognostic features of pancreatic carcinoma in situ. This entity is probably overlooked due to a number of reasons, including the fact that, in most cases, pancreatic ductal carcinomas are extensively infiltrative at the time of surgical removal; the atypical epithelial changes in the intraductal carcinoma had been overlooked in the presence or absence of an invasive component; epithelial changes may be missed due to insufficient sampling; and last, the differentiation with atypical epithelial hyperplasia is a subjective matter. Intraductal carcinoma of the pancreas is a distinct pathological entity with characteristic morphologic changes restricted to the ductal epithelium, bearing important prognostic implications.