Transmission of yellow fever vaccine virus through blood transfusion and organ transplantation in the USA in 2021: report of an investigation

BACKGROUND

In 2021, four patients who had received solid organ transplants in the USA developed encephalitis beginning 2-6 weeks after transplantation from a common organ donor. We describe an investigation into the cause of encephalitis in these patients.

METHODS

From Nov 7, 2021, to Feb 24, 2022, we conducted a public health investigation involving 15 agencies and medical centres in the USA. We tested various specimens (blood, cerebrospinal fluid, intraocular fluid, serum, and tissues) from the organ donor and recipients by serology, RT-PCR, immunohistochemistry, metagenomic next-generation sequencing, and host gene expression, and conducted a traceback of blood transfusions received by the organ donor.

FINDINGS

We identified one read from yellow fever virus in cerebrospinal fluid from the recipient of a kidney using metagenomic next-generation sequencing. Recent infection with yellow fever virus was confirmed in all four organ recipients by identification of yellow fever virus RNA consistent with the 17D vaccine strain in brain tissue from one recipient and seroconversion after transplantation in three recipients. Two patients recovered and two patients had no neurological recovery and died. 3 days before organ procurement, the organ donor received a blood transfusion from a donor who had received a yellow fever vaccine 6 days before blood donation.

INTERPRETATION

This investigation substantiates the use of metagenomic next-generation sequencing for the broad-based detection of rare or unexpected pathogens. Health-care workers providing vaccinations should inform patients of the need to defer blood donation for at least 2 weeks after receiving a yellow fever vaccine. Despite mitigation strategies and safety interventions, a low risk of transfusion-transmitted infections remains.

FUNDING

US Centers for Disease Control and Prevention (CDC), the Biomedical Advanced Research and Development Authority, and the CDC Epidemiology and Laboratory Capacity Cooperative Agreement for Infectious Diseases.

Ocular Human Papillomavirus Infections

CONTEXT

- Human papillomavirus (HPV) has a well-known role in the pathogenesis of squamous cell carcinoma and precursor lesions of the cervix, anogenital region, and head and neck, but its role in the development of squamous neoplasms of the eye, particularly the conjunctiva, remains unclear.

OBJECTIVE

- To review recent evidence implicating HPV in the pathophysiology of ocular lesions.

DATA SOURCES

- Published articles obtained from a PubMed search of the English literature were the primary sources for this review.

CONCLUSIONS

- The low-risk HPV types 6 and 11 appear to play a role in the development of at least a subset of conjunctival squamous papillomas. The role of HPV in the pathogenesis of pterygium and ocular surface squamous neoplasia is less well defined. There is evidence to suggest that HPV may be a cofactor in the development of these lesions, acting in concert with ultraviolet radiation and/or human immunodeficiency virus infection in a subgroup of cases.

Interobserver and intraobserver reproducibility in focal cortical dysplasia (malformations of cortical development)

PURPOSE

Malformations of cortical development (MCD) (cortical dysplasias) are well-recognized causes of intractable epilepsy. Although a histologic classification system for MCD has been proposed by Palmini et al. (Neurology; 2004; 62:S2), studies to date have not assessed reproducibility. The purpose of this study was to analyze inter- and intraobserver agreement among eight experienced neuropathologists (NPs) with respect to this classification system.

METHODS

Sections from 26 epilepsy resections were selected to represent the range of pathologies described by Palmini et al. Recuts of single sections from each case were sent to the NPs to classify. The slides were resent at a later date for reclassification. Kappa analysis for both inter- and intraobserver concordance was performed.

RESULTS

Interobserver agreement was moderate (kappa = 0.4968). There was > or =62.5% (5 of 8 NPs) agreement for 19 of 26 cases. The greatest concordance was present when making focal cortical dysplasia (FCD) types IIA/B classifications (12 of the 14 cases with > or =75% consensus). Mild MCD (types I/II) and FCD types IA/B classifications were the least reproducible, and used most frequently in cases without consensus. Intraobserver concordance was moderate to very good (range kappa = 0.4654-0.8504). The category with the fewest classification changes made on reevaluation was FCD type IIB (4.2%), whereas that with the most changes was mild MCD (types I/II) (52.9%).

DISCUSSION

Interobserver concordance using this approach was moderate. The classification categories with the greatest concordance were FCD type IIA/B, and the least, mild MCD and FCD types IA/B. In addition, difficulty in differentiating Mild MCD/FCD type I lesions from normal and/or gliotic tissue was noted.

Vital signs: how early can resident evaluation predict acquisition of competency in surgical pathology?

OBJECTIVES

To determine whether a longitudinal, case-based evaluation system can predict acquisition of competency in surgical pathology and how trainees at risk can be identified early.

DESIGN

Data were collected for trainee performance on surgical pathology cases (how well their diagnosis agreed with the faculty diagnosis) and compared with training outcomes. Negative training outcomes included failure to complete the residency, failure to pass the anatomic pathology component of the American Board of Pathology examination, and/or failure to obtain or hold a position immediately following training.

FINDINGS

Thirty-three trainees recorded diagnoses for 54 326 surgical pathology cases, with outcome data available for 15 residents. Mean case-based performance was significantly higher for those with positive outcomes, and outcome status could be predicted as early as postgraduate year-1 (P  =  .0001). Performance on the first postgraduate year-1 rotation was significantly associated with the outcome (P  =  .02). Although trainees with unsuccessful outcomes improved their performance more rapidly, they started below residents with successful outcomes and did not make up the difference during training. There was no significant difference in Step 1 or 2 United States Medical Licensing Examination (USMLE) scores when compared with performance or final outcomes (P  =  .43 and P  =  .68, respectively) and the resident in-service examination (RISE) had limited predictive ability.

DISCUSSION

Differences between successful- and unsuccessful-outcome residents were most evident in early residency, ideal for designing interventions or counseling residents to consider another specialty.

CONCLUSION

Our longitudinal case-based system successfully identified trainees at risk for failure to acquire critical competencies for surgical pathology early in the program.

Systemic distribution of West Nile virus infection: postmortem immunohistochemical study of six cases

Rare cases of West Nile virus (WNV)-associated inflammation outside the central nervous system (CNS) have been reported. We evaluated the systemic distribution of WNV in postmortem tissues during encephalitis in six patients using immunohistochemistry. WNV antigens were detected in neurons of CNS (all 6 cases), kidney (4 cases), lungs (2 cases), pancreas (2 cases), thyroid (2 cases), intestine (2 cases), stomach (1 case), esophagus (1 case), bile duct (1 case), skin (1 case), prostate (1 case) and testis (1 case). In systemic organs epithelial cells were infected. In none of the six cases were viral antigens identified in hepatocytes, heart, adrenal gland, nerves, skeletal muscles, bone, vessels and fat. All cases in which viral antigens were identified in systemic organs in addition to CNS were severely immunocompromised transplant recipients. With the exception of testis and brain, most foci of infection were not associated with inflammation. While the absence of inflammation may in part be due to patient immunosuppression or to possible transient nature of any host response, compartmentalization of viral antigen to the luminal region of epithelial cells may sequester WNV from immune recognition. Comparison of our findings with previous reports suggests that patients with WNV encephalitis can have widespread systemic infection.

Intranasal administration of the growth-compromised HSV-2 vector DeltaRR prevents kainate-induced seizures and neuronal loss in rats and mice

Identification of targets and delivery platforms for gene therapy of neurodegenerative disorders is a clinical challenge. We describe a novel paradigm in which the neuroprotective gene is the herpes simplex virus type 2 (HSV-2) antiapoptotic gene ICP10PK and the vector is the growth-compromised HSV-2 mutant DeltaRR. DeltaRR is delivered intranasally. It is not toxic in rats and mice. ICP10PK is expressed in the hippocampus of the DeltaRR-treated animals for at least 42 days in the absence of virus replication and late virus gene expression. Its expression is regulated by an AP-1 amplification loop. Intranasally delivered DeltaRR prevents kainic acid-induced seizures, neuronal loss, and inflammation, in both rats and mice. The data suggest that DeltaRR is a promising therapeutic platform for neurodegenerative diseases.

Newly defined central nervous system neoplasms

In recent years, numerous new entities or variants of recognized central nervous system tumors have been described in the literature, and the morphologic spectrum of these neoplasms is delineated incompletely. The accurate diagnosis and classification of these lesions is important to ensure that patients receive adequate therapy and prognostic information. The clinicopathologic features and differential diagnosis of 4 new entities, including the chordoid glioma of the third ventricle, cerebellar liponeurocytoma, atypical teratoid/rhabdoid tumor, and papillary glioneuronal tumor, are discussed in this review.

Temporal lobe intraparenchymal retained foreign body from remote orbital trauma

We present the case of a 35-year-old man with a new onset of seizure disorder who was found to harbor an intraparenchymal retained foreign body related to remote orbital trauma. Imaging revealed a rim-enhancing anterior medial temporal lobe mass. Histologic evaluation of the resected mass showed evidence of acute and chronic inflammation with associated foreign material. The patient described a "bar fight" 16 years previously in which he received a blow to the orbit with a pool cue stick. The diagnosis of a foreign body reaction should be considered when an intraparenchymal mass is identified in this location.

Long-term control after resection and gamma knife surgery of an intracranial clear cell meningioma: case report

Clear cell meningioma (CCM) is a rare variant of meningioma characterized by sheets of polygonal cells with clear cytoplasm, a feature attributable to its high glycogen content. Authors have described its propensity to recur and metastasize despite its benign pathological characteristics. Clinical response to radiation in these reports has varied. The authors present the case of a 7-year-old girl with a large petroclival CCM who underwent a staged subtotal resection and subsequent gamma knife surgery (GKS). Initially, the residual tumor decreased in size, but 6 years later, it had regrown (9 mm in size). A second GKS treatment was performed and the mass completely regressed without further complication. The findings in this case suggest that GKS is a safe and effective adjunct for residual and recurrent CCM after resection. The delayed recurrence also emphasizes the importance of undertaking close follow-up examination after treating this potentially aggressive variant of meningioma.

Successful outcome of progressive multifocal leukoencephalopathy in a renal transplant patient

We report the case of a 47-year-old man who developed progressive multifocal leukoencephalopathy (PML) after receiving immuno-suppressive therapy for renal transplantation. The patient presented with a focal seizure and cognitive changes 5 months post-transplantation. He was found to have enhancing lesions in the parietal lobe and typical findings of PML in a brain biopsy. Immunosuppression was discontinued and the neurological symptoms gradually resolved over a period of 4 weeks. The patient is free of any neurological symptoms 36 months after the diagnosis of PML and imaging studies demonstrate resolution of the PML lesions. The patient returned to hemodialysis 3 months after immunosuppression was discontinued. We also present a review of the literature on PML in renal transplant recipients.

Herpes simplex virus type 1-induced encephalitis has an apoptotic component associated with activation of c-Jun N-terminal kinase

Herpes simplex virus type 1 (HSV-1) triggered apoptosis in hippocampal cultures, as determined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) and immunohistochemistry with antibody specific for the large fragment of activated caspase 3. The levels of phosphorylated (activated) c-Jun N-terminal kinase (JNK) were also increased in HSV-1-infected hippocampal cultures as were the levels of activated c-Jun, its target. JNK activation was involved in HSV-1-induced apoptosis as evidenced by apoptosis inhibition with the JNK inhibitor SP600125. HSV-2 activated the mitogen-activated protein kinase/extracellular regulated protein kinase (MEK/ERK) survival pathway and did not trigger apoptosis in hippocampal cultures. The MEK specific inhibitor U0126 inhibited ERK activation and caused a significant increase in the percent TUNEL(+) cells in HSV-2-infected cultures, indicating that the failure of HSV-2 to trigger apoptosis is due to its ability to activate the MEK/ERK survival pathway. JNK was also activated in brain tissues from patients with HSV-associated acute focal encephalitis (HSE) that were positive for HSV-1 antigen. JNK activation correlated with apoptosis, as determined by immunohistochemistry with antibody to activated caspase 3 or cleaved poly (ADP-ribose) polymerase (PARP). The data suggest that HSE has an apoptotic component that may contribute to disease pathogenesis.

Aggregation of actin and cofilin in identical twins with juvenile-onset dystonia

The neuropathology of the primary dystonias is not well understood. We examined brains from identical twins with DYT1-negative, dopa-unresponsive dystonia. The twins exhibited mild developmental delays until age 12 years when they began developing rapidly progressive generalized dystonia. Genetic, metabolic, and imaging studies ruled out known causes of dystonia. Cognition was subnormal but stable until the last few years. Death occurred at ages 21 and 22 years. The brains were macroscopically unremarkable. Microscopic examination showed unusual glial fibrillary acidic protein-immunoreactive astrocytes in multiple regions and iron accumulation in pallidal and nigral neurons. However, the most striking findings were 1) eosinophilic, rod-like cytoplasmic inclusions in neocortical and thalamic neurons that were actin depolymerizing factor/cofilin-immunoreactive but only rarely actin-positive; and 2) abundant eosinophilic spherical structures in the striatum that were strongly actin- and actin depolymerizing factor/cofilin-positive. Electron microscopy suggested that these structures represent degenerating neurons and processes; the accumulating filaments had the same dimensions as actin microfilaments. To our knowledge, aggregation of actin has not been reported previously as the predominant feature in any neurodegenerative disease. Thus, our findings may shed light on a novel neuropathological change associated with dystonia that may represent a new degenerative mechanism involving actin, a ubiquitous constituent of the cytoskeletal system.

Reduced thrombomodulin in human peripheral nerve microvasculature

Thrombomodulin (TM), a vascular endothelial receptor, terminates the actions of thrombin and accelerates activated protein C formation. TM is ubiquitous throughout the systemic microcirculation but is reduced in brain regions predisposed to lacunar infarction. We investigated whether TM is present within human nerve and differentially expressed according to vessel caliber and proximity to the blood-nerve barrier. Vascular endothelial TM was detected on sural nerve biopsies with immunohistochemistry. The proportion of TM-positive microvessels was expressed relative to total von Willebrand factor (vWF)-positive vessels. Although vWF was detectable in all microvessels, TM expression was absent from the perineurial vessels. TM was detected in 47% (15-80%, 95% confidence level) of larger epineurial arterioles, in 43% (30-61%) of smaller epineurial vessels, and in 30% (19-47%) of endoneurial vessels. These findings demonstrate that TM is present in human nerve microvasculature but is regionally deficient in proximity to the blood-nerve barrier, which may predispose nerve to microvascular ischemia in inflammatory/prothrombotic conditions.

Thrombomodulin deficiency in human diabetic nerve microvasculature

Human diabetic neuropathy is multifactorial in etiology, with ischemia as a final common pathology. Although impaired vascular endothelial cell function in diabetic microvascular injury is established, the role of thrombomodulin (TM)-dependent protein C antithrombotic mechanism in the pathogenesis of neuropathy is unclear. This neuropathologic case-control study investigated whether vascular endothelial TM expression is deficient in peripheral nerve microvessels in diabetic neuropathy. Sural nerve biopsies from 7 patients with diabetic neuropathy and 10 with axonal neuropathy without vasculopathy were immunostained with anti-TM and anti-von Willebrand factor (vWF; an endothelial cell marker) antibodies. The proportion of TM-positive microvessels was expressed relative to total vWF-staining vessels, according to vessel caliber and regional distribution within the nerve. In diabetic nerves compared with reference controls, the proportion of TM-positive endoneurial microvessels was 15-fold lower (0.02 vs. 0.30 in diabetic nerves vs. controls, P < 0.004), and the proportion of small-caliber epineurial microvessels was 10-fold lower (0.04 vs. 0.43, P < 0.001). No TM expression was detected at the perineurium in diabetic or control nerves. We demonstrate a substantial reduction of vascular endothelial TM expression throughout human diabetic neuropathy. These findings suggest that an impaired native TM-dependent protein C antithrombotic mechanism may contribute to microvascular ischemia in the pathogenesis of diabetic neuropathy.

Decreasing incidence of sudden death due to undiagnosed primary central nervous system tumors

CONTEXT

Although most fatal brain tumors are diagnosed well before a patient's death, occasionally medical examiners and coroners encounter cases in which the presence of a primary tumor of the central nervous system (CNS) was not suspected prior to death. Analysis of such cases can shed light on specific pitfalls hindering the diagnosis of brain tumors. In addition, by analyzing the incidence of these cases in a large autopsy series, one can draw conclusions about the evolving effectiveness of medical diagnosis.

OBJECTIVE

To determine the incidence of deaths due to undiagnosed primary CNS tumors in the era of advanced neuroimaging techniques.

DESIGN

Records from forensic autopsies performed during a 20-year period (1980-1999) at the Office of the Chief Medical Examiner of the State of Maryland were reviewed to identify cases in which death was caused by primary CNS tumors undiagnosed prior to the patient's death.

RESULTS

We present 11 cases of undiagnosed primary CNS tumors resulting in sudden death that were identified among 54 873 forensic autopsies. Sudden deaths due to undiagnosed CNS neoplasms account for a significantly lower percentage of cases in our study (0.02%) than in similar series reported prior to 1980 (> or =0.16%).

CONCLUSIONS

We hypothesize that improvements in imaging techniques, notably the introduction of computed tomography and magnetic resonance imaging, have resulted in increased early detection of CNS neoplasms. However, vague or short-term symptoms and limited health care access can dissuade patients from seeking medical attention and result in failure to diagnose these tumors correctly.

Intraneuronal abeta-amyloid precedes development of amyloid plaques in Down syndrome

CONTEXT

Down syndrome patients who live to middle age invariably develop the neuropathologic features of Alzheimer disease, providing a unique situation in which to study the early and sequential development of these changes.

OBJECTIVE

To study the development of amyloid deposits, senile plaques, astrocytic and microglial reactions, and neurofibrillary tangles in the brains of young individuals (<30 years of age) with Down syndrome.

METHODS

Histologic and immunocytochemical study of a series of autopsy brains (n = 14, from subjects aged 11 months to 56 years, with 9 subjects <30 years) examined at the Office of the Chief Medical Examiner of the State of Maryland and The Johns Hopkins Hospital.

RESULTS

The principal observations included the presence of intraneuronal Abeta immunostaining in the hippocampus and cerebral cortex of very young Down syndrome patients (preceding the extracellular deposition of Abeta) and the formation of senile plaques and neurofibrillary tangles.

CONCLUSIONS

We propose the following sequence of events in the development of neuropathologic changes of Alzheimer disease in Down syndrome: (1) intracellular accumulation of Abeta in neurons and astrocytes, (2) deposition of extracellular Abeta and formation of diffuse plaques, and (3) development of neuritic plaques and neurofibrillary tangles with activation of microglial cells.

Central neurocytomas express photoreceptor differentiation

BACKGROUND

Central neurocytomas are composed of mature neuronal elements, frequently arranged in rosettes similar to those present in pineocytomas. This suggests the possibility of similar patterns of differentiation, including photoreceptor differentiation. The authors analyzed the immunoreactivity of central neurocytomas for retinal S-antigen, neuronal, glial, and neuroendocrine markers.

METHODS

Thirty-three central neurocytomas were analyzed with reference to their clinicopathologic characteristics, immunoreactivity, and the possibility that anaplastic histologic features correlated with aggressive clinical behavior.

RESULTS

There were 18 male and 15 female patients. The median age at diagnosis was 30 years (range, 3-69 years). All of the tumors with specified location were related to the ventricles. Thirty-two tumors were diagnosed at surgery and 1 at autopsy. Histologic features included mineralization (20 of 33), foci of necrosis (4 of 33), chronic inflammation (4 of 33), ganglion cell differentiation (1 of 33), and lipomatous differentiation (1 of 33). None of the lesions had significant nuclear pleomorphism, mitotic activity, or vascular endothelial proliferation. Immunohistochemistry included expression of synaptophysin (33 of 33), neuron specific enolase (31 of 33), S-100 protein (25 of 33), retinal S-antigen (14 of 24), somatostatin (8 of 27), glial fibrillary acidic protein (4 of 33), neurofilament protein (3 of 22), and leucine enkephalin (1 of 27). At follow-up, 15 of 23 patients were alive an average of 8.1 years (range, 0.91-35.9 years) after surgery.

CONCLUSIONS

Central neurocytomas behave as slowly growing neoplasms that remain confined within one or several supratentorial ventricles and are associated with long survival after surgical excision. Malignant forms with aggressive clinical behavior were not found. The neoplastic cells can express photoreceptor differentiation possibly relating central neurocytomas to pineocytomas. Adipocyte differentiation may be present, and the possibility of a relation between the central neurocytoma and cerebellar liponeurocytoma should be entertained.

Postmortem diagnosis of cerebral malaria

Human cerebral malaria is a frequent encephalopathy that occurs in the endemic tropical-subtropical zones. There are a smaller number of imported cases in continental zones where the diagnosis sometimes remains difficult to establish. Fifteen days after the death of a 36-year-old male French citizen in Africa, an investigation to determine the cause of death was conducted. Histologic examination of the brain permitted the diagnosis of cerebral malaria. Because of the popularity of overseas tourism and because this disorder may appear as "sudden death," these victims may be referred to a forensic pathologist. This case demonstrates the role a forensic pathologist may play in determining the cause of death in cerebral malaria.

Foamy cells with oligodendroglial phenotype in childhood ataxia with diffuse central nervous system hypomyelination syndrome

Childhood ataxia with diffuse central nervous system hypomyelination syndrome (CACH) is a recently described leukodystrophy of unknown etiology. To characterize the neuropathological features and gain insight as to the pathogenesis of this disorder, we studied cerebral tissue from six patients with the CACH syndrome. Evaluation of toluidine blue-stained, semithin sections of white matter from CACH patients disclosed unusual cells with "foamy" cytoplasm, small round nuclei and fine chromatin. Electron microscopy (EM) revealed cells in the white matter with abundant cytoplasm containing many mitochondria and loosely clustered, membranous structures, but lacking the lysosomal structures seen in macrophages. Further analysis of tissue sections with antibodies and special stains demonstrated that the abnormal cells with abundant cytoplasm labeled with oligodendroglial markers, but did not react with macrophage or astrocytic markers. Double immunolabeling with macrophage and oligodendroglial markers clearly distinguished macrophages from the "foamy" oligodendroglial cells (FODCs). Proteolipid protein (PLP) mRNA in situ hybridization demonstrated PLP mRNA transcripts in a high proportion of oligodendrocytes in CACH patients compared to control patients, and PLP mRNA transcript signal in cells, morphologically consistent with FODCs. Normal and pathological brain control tissues did not contain FODCs. These neuropathological findings will be useful pathological identifiers of CACH, and may provide clues to the pathogenesis of this disorder.

A clinicopathological study of 15 patients with neuroglial heterotopias and encephaloceles of the middle ear and mastoid region

OBJECTIVES/HYPOTHESIS

Heterotopic masses of neuroglial tissue involving non-midline structures, specifically, the middle ear region, are exceptional. The pathogenesis of these lesions and, in particular, their relation to encephaloceles, is uncertain.

STUDY DESIGN AND METHODS

H&E-stained sections from 15 lesions diagnosed as neuroglial heterotopias or encephaloceles involving the middle ear region were reviewed. Radiographic or operative evidence of a central nervous system (CNS) relation and clinical factors possibly related to pathogenesis were analyzed.

RESULTS

All 15 lesions (from six men and nine women; mean age, 49 y; range, 16-67 y), regardless of their relation to the CNS, were composed of varying proportions of neurons and glia with associated chronic inflammatory cells and reactive gliosis. No significant ependymal or choroid plexus component was present. Operative findings revealed that two lesions had definite CNS connections and two were unrelated to the CNS; this relation could not be determined in the remaining cases. Seven of 10 patients for whom clinical information was available had a history of chronic otitis media or mastoiditis or both; four of these seven patients also had a history of previous trauma or surgery. Three patients, including both patients whose lesions had no demonstrable CNS attachment, had no predisposing factors.

CONCLUSIONS

Most neuroglial heterotopias of the middle ear are probably acquired encephaloceles. These lesions occur in older patients than do their midline counterparts. Determination of the relation of these lesions to adjacent CNS structures must be done radiographically or using operative findings, because histology alone cannot be reliably used to render an accurate diagnosis.

Cytokeratin 7 and 20 expression in choroid plexus tumors: utility in differentiating these neoplasms from metastatic carcinomas

Tumors derived from choroid plexus epithelium are uncommon and may exhibit a wide variety of histologic patterns. They often are difficult to distinguish from metastatic carcinomas. Previous studies that addressed this issue yielded conflicting results. Recent reports have demonstrated that evaluation of coordinate expression of cytokeratin (CK) 7 and CK20 aids in distinguishing primary from metastatic lesions in a number of anatomic sites and that tumors that commonly are metastatic to the brain retain their CK7/CK20 immunophenotype in this location. We examined 35 choroid plexus tumors with a panel of antibodies to determine their CK7/CK20 immunophenotype. Tumors from 35 patients (7 male, 28 female; mean age, 25 years), including 31 choroid plexus papillomas and 4 atypical papillomas, were evaluated. All tumors were intraventricular or within the cerebellopontine angle and composed predominantly of orderly columnar epithelial cells resting on distinct fibrovascular cores. Atypical papillomas contained combinations of focal loss of architectural pattern, increased mitotic activity, necrosis, and brain parenchymal invasion. No lesion was unequivocally malignant. Twenty-six tumors (74%), including all atypical papillomas, were CK7 positive and CK20 negative. Two tumors stained with both markers, one stained with CK20 only, and six stained with neither marker. Other findings included expression of glial fibrillary acidic protein in 24 tumors, S-100 protein in 19 tumors, transthyretin in 31 tumors, Ber EP4 in 1 tumor, CAM5.2 in 33 tumors, epithelial membrane antigen in 4 tumors, and pancytokeratin in 27 tumors. Our results indicate that the majority of choroid plexus tumors have a CK7-positive/CK20-negative immunophenotype. This finding may be useful in differentiating these lesions from metastatic carcinomas that have differing CK7/CK20 profiles.

Extracranial sinonasal tract meningiomas: a clinicopathologic study of 30 cases with a review of the literature

Extracranial meningiomas of the sinonasal tract are rare tumors. These tumors are frequently misclassified, resulting in inappropriate clinical management. To date, there has been no comprehensive study to evaluate the clinicopathologic aspects of meningioma in these anatomic sites. Thirty cases of sinonasal tract meningiomas diagnosed between 1970 and 1992 were retrieved from the files of the Otorhinolaryngic Registry of the AFIP. Histologic features were reviewed, immunohistochemical studies were performed, patient follow up was obtained, and the results were statistically analyzed. The patients included 15 females and 15 males, aged 13 to 88 years (mean, 47.6 yrs). Patients presented clinically with a mass, epistaxis, sinusitis, pain, visual changes, or nasal obstruction, dependent on the anatomic site of involvement. Symptoms were present for an average of 31.1 months. The tumors affected the nasal cavity (n = 14), nasopharynx (n = 3), frontal sinus (n = 2), sphenoid sinus (n = 2). or a combination of the nasal cavity and ethmoid, frontal, sphenoid, and/or maxillary sinuses (n = 9). The tumors ranged in size from 1.0 to 8.0 cm in greatest dimension (mean, 3.5 cm). Radiographic studies demonstrated a central nervous system connection in six cases. The tumors often eroded the bones of the sinuses (n = 18) and involved the surrounding soft tissues, the orbit, and occasionally the base of the skull. Histologically, the tumors demonstrated features similar to intracranial meningiomas. The majority were of the meningothelial type (n = 23), although there were three atypical meningiomas. Immunohistochemical studies confirmed the diagnosis of meningioma with positive reactions for epithelial membrane antigen (EMA) and vimentin (all tested). The differential diagnosis includes paraganglioma, carcinoma, melanoma, psammomatoid ossifying fibroma, and angiofibroma. Surgical excision was used in all patients. Three patients died with recurrent disease (mean, 1.2 yrs), one was alive with recurrent disease (25.6 years), and the remaining 24 patients were alive or had died of unrelated causes (mean, 13.9 yrs) at the time of last follow up (two patients were lost to follow up). Extracranial sinonasal tract meningiomas are rare tumors which need to be considered in the differential diagnosis of sinonasal tumors. A whorled growth pattern and psammoma bodies, combined with positive EMA and vimentin immunohistochemical reactions, can confirm the diagnosis of meningioma. The overall prognosis is good, without a difference in outcome between benign and atypical meningiomas.

Retroperitoneal peripheral hemangioblastoma: a case report and review of the literature

Central nervous system hemangioblastomas are uncommon tumors of controversial etiology that are usually found in the posterior fossa of the cranial cavity, retina, and spinal cord. Peripheral involvement is rare; only isolated case reports have been identified. We report an unusual case of hemangioblastoma involving the retroperitoneum. A 47-year-old African-American man presented with polycythemia on routine laboratory testing. Computed tomography revealed a large retroperitoneal mass near the pancreas, in a left suprarenal location, without adrenal involvement and without attachment to a nerve. Although hemangioblastoma may be associated with the von Hippel-Lindau syndrome, this patient did not have any of the stigmata of this disease. The histologic features included a highly vascular tumor with cellular areas composed of plump, pleomorphic spindled and epithelioid (stromal) cells with variable cytoplasmic lipid vacuoles and hypocellular areas with inflammatory cells and collagenous fibrils. Immunohistochemical staining showed that the tumor (stromal) cells were positive for vimentin, calponin, S-100 protein, neuron-specific enolase, and CD57 and negative for glial fibrillary acidic protein, cytokeratins, epithelial membrane antigen, CD34, HMB-45, desmin, and the actins. These morphologic and immunohistochemical findings are consistent with hemangioblastoma. To our knowledge this is the first reported case of a hemangioblastoma in this location. Based on this case we conclude that hemangioblastoma may occur in the retroperitoneum and outside of the central nervous system in a patient without von Hippel-Lindau syndrome. The immunoprofile of this case suggests that hemangioblastomas are mesenchymal neoplasms exhibiting both neural and myofibroblastic differentiation.

Dysembryoplastic neuroepithelial tumor: an immunohistochemical study with myelin oligodendrocyte glycoprotein

CONTEXT

The dysembryoplastic neuroepithelial tumor (DNT) is an uncommon lesion characterized by a heterogeneous population of neurons, astrocytes, and oligodendroglia-like cells (OLCs). The basic nature of the DNT and its constituent cells, particularly the OLCs, remains unresolved; some authors favor a neuronal origin, and others propose a glial or mixed origin for these cells.

DESIGN

We examined 11 DNTs with antibodies to myelin oligodendrocyte glycoprotein, a marker of mature oligodendrocytes.

RESULTS

All DNTs studied (7 from males, 4 from females; age range of patients, 2-37 years) were composed of varying proportions of neurons, astrocytes, and OLCs. Membrane or cytoplasmic immunoreactivity for myelin oligodendrocyte glycoprotein was found in many OLCs in 9 of 11 cases. The number of myelin oligodendrocyte glycoprotein-positive OLCs was variable: >75% of the OLCs were positive in 5 cases, 25% to 75% of the OLCs were positive in 2 cases, and <25% of the OLCs were positive in 2 cases.

CONCLUSION

These findings suggest that many of the OLCs represent mature oligodendrocytes and support the notion that DNTs are heterogenous lesions composed of multiple, mature cell types.

Mycobacterial spindle cell pseudotumor of the brain: a case report and review of the literature

Spindle cell pseudotumors found in the skin, lymph nodes, bone marrow, spleen, lungs, and retroperitoneum have been reported recently in immunosuppressed patients, including those with acquired immunodeficiency syndrome. The authors report a similar lesion limited to the brain in a 38-year-old human immunodeficiency virus-negative man receiving steroid therapy for treatment of sarcoidosis. Histopathologically the lesions were composed of spindle and epithelioid histiocytes, small foci of necrosis, and numerous acid-fast bacilli. The acid-fast bacilli were determined by culture and polymerase chain reaction to be Mycobacterium avium intracellulare. Because of the uncommon histologic appearance of this lesion and the potential for treatment if recognized, mycobacterial spindle cell pseudotumors should be included in the differential diagnosis of spindle cell lesions in the brain in immunosuppressed patients.

Extracerebellar primitive neuroectodermal tumors: A clinicopathologic study with bcl-2 and CD99 immunohistochemistry

Supratentorial primitive neuroectodermal tumors (S-PNETs) are uncommon lesions that occur predominantly in children and are histologically identical to cerebellar medulloblastomas. Like their cerebellar counterparts, S-PNETs often show divergent differentiation along neuronal, glial, and mesenchymal lines. The relationship of S-PNETs to medulloblastoma and other embryonal neoplasms remains controversial, largely because the cell of origin and histogenesis of these lesions are incompletely understood. To clarify these issues, we examined eight S-PNETs with antibodies to bcl-2 (an antiapoptosis protooncogene that has been postulated to be a marker of neuronal differentiation) and CD99 (a glycoprotein present in most peripheral embryonal tumors). S-PNETs in eight patients (seven males and one female; age range, 2 months to 40 years) were studied. All lesions were composed predominantly of small round cells with deeply basophilic nuclei and minimal surrounding cytoplasm. Tumors in two patients demonstrated no evidence of differentiation, two tumors neuronal differentiation only, and four tumors both neuronal and glial differentiation. No tumors stained with CD99. Three tumors showed focal, strong cytoplasmic staining with bcl-2. The positive lesions included one tumor showing neuronal differentiation only and two tumors with both neuronal and astrocytic differentiation. Patients were treated with various combinations of radiation and chemotherapy; five patients died from their tumor a mean of 1.7 years after diagnosis, two patients were alive with residual disease at 3 months and 3 years, and one patient was alive without disease at 17 months. Our findings suggest that bcl-2 positivity may identify a subgroup of patients having inhibition of apoptosis as a pathogenetic mechanism; we were unable to show any definite relationship between bcl-2 staining and neuronal differentiation. Despite their morphologic similarity, supratentorial and peripheral embryonal tumors appear to be distinct pathogenetic lesions, as evidenced by their different staining patterns with CD99.

Intracranial extracerebral neuroglial heterotopia: A case report and review of the literature

Heterotopic masses of neuroglial tissue are uncommon and most frequently involve extracranial midline structures. We report an unusual case of an intracranial, extracerebral neuroglial heterotopia involving the middle and anterior cranial fossae of a 5-year-old girl who presented with facial asymmetry. The lesion was composed of mature but disorganized gray and white matter admixed with surrounding soft tissues and exhibited histologic features reminiscent of cortical dysplasia. These rare lesions have been postulated to arise from a protrusion of tissue from the neuraxis through a pial defect, from abnormalities in the migration of embryonic neuroepithelial tissue, or from an accessory evagination of the neural tube inferior to the telencephalic vesicles. Regardless of the underlying pathogenic mechanism, these lesions must be histologically distinguished from both teratomas and primary central nervous system neoplasms.

Adult-onset nemaline myopathy: a case report and review of the literature

Nemaline (rod) myopathy is a congenital muscle disease with a wide spectrum of phenotypes, ranging from forms with neonatal onset and fatal outcome to asymptomatic forms. An adult-onset variant is characterized by large numbers of rod-containing myofibers, numerous rods per affected myofiber, and the absence of specific structural abnormalities typical of other muscle diseases. Few cases fulfilling these criteria have been described in the literature. Rare cases have had an associated inflammatory component, and the majority of these have occurred in patients with an underlying immunologic disorder. We present an unusual case of an immunologically competent 65-year-old man with late-onset nemaline myopathy, who was previously diagnosed with an inflammatory myopathy based on a muscle biopsy that contained chronic inflammation. His symptoms consisted of a 2-year history of progressive proximal muscle weakness; his family history was unremarkable. A neurologic examination confirmed the presence of bilateral proximal muscle weakness, normal sensation, and decreased upper and lower extremity reflexes. Creatine kinase levels were normal, and electromyographic findings indicated a myopathic process. A modified trichrome stain of the right biceps muscle revealed granular, basophilic, centrally located rods in the atrophic myofibers. Ultrastructurally, these myofibers contained osmiophilic rectangular structures with a latticelike appearance typical of nemaline myopathy. This case illustrates that adult-onset nemaline myopathy, although rare, should be considered in the differential diagnosis of an inflammatory myopathy.

Subependymal giant cell astrocytoma: a clinicopathologic study with HMB45 and MIB-1 immunohistochemical analysis

Subependymal giant cell astrocytomas (SEGAs) occur in approximately 6% of patients with tuberous sclerosis (TS) and are often considered to be a forme fruste or partial expression of this disorder. Recently, a number of other TS-associated lesions, including pulmonary and uterine lymphangiomyomatosis, renal angiomyolipoma, and cardiac rhabdomyoma, were shown to stain with the monoclonal antibody HMB45, suggesting a pathogenetic relationship among these lesions. Seven SEGAs in six patients (three men and three women; age range, 2-55 yr; mean, 24 yr) were studied. Cutaneous and other central nervous system features of TS were present in two patients. All of the SEGAs were intraventricular in location and were characterized by large, round, eosinophilic and spindle-shaped cells, with nuclear pseudoinclusions and mild nuclear pleomorphism, arranged in a vaguely perivascular pattern. All of the SEGAs were negative with HMB45 immunostaining. MIB-1 immunostaining was also performed in all of the cases, and MIB-1 indices (the percentage of MIB-1-positive nuclei) ranged from 0.1 to 3.8 (mean, 1.1). Two patients required an additional surgical procedure for residual/recurrent tumor; three patients are alive without evidence of disease 5 to 11 years after diagnosis; and one patient was lost to follow-up. SEGAs are generally slowly growing intraventricular neoplasms, as evidenced by their low MIB-1 labeling. Unlike other TS-associated lesions, SEGAs do not stain with HMB45.

Lymphangiomyomatosis of the uterus associated with tuberous sclerosis and malignant neoplasia of the female genital tract: a report of two cases

Lymphangiomyomatosis (LAM) is a rare disease that does not generally affect the female genital tract. We report two cases of uterine involvement by LAM in young women with tuberous sclerosis and renal angiomyolipomas. In both, the uterine lesions were grossly inapparent and were discovered during microscopic examination of hysterectomy specimens removed during surgical treatment for a primary ovarian adenocarcinoma with peritoneal and lymph node metastases in one case and a retroperitoneal lymphangiomyoma in the other. In one case, an area of uterine LAM with atypical features was interpreted as focal sarcomatous transformation. This patient also had pelvic and paraaortic lymph node involvement by typical lymphangiomyomas, a small uterine angiomyoma, and an occult primary endometrial adenocarcinoma. Immunostains for HMB-45 were strongly positive in the uterine LAM in both cases, the retroperitoneal and lymph node lymphangiomyomatous lesions, the uterine angiomyoma, and a resected renal angiomyolipoma. Although LAM is a rare uterine lesion, it must be distinguished from a variety of uterine smooth-muscle tumors.

Symptomatic Mycobacterium avium complex infection of the central nervous system. A case report and review of the literature

Mycobacterium avium complex infections rarely involve the central nervous system, even in patients with widely disseminated disease. We report a case of disseminated M. avium complex infection presenting with central nervous system symptoms in a patient with Hodgkin's disease. Neurologic findings included disorientation, nuchal rigidity, seizures, an extensor plantar response, cerebrospinal fluid studies consistent with meningitis, and eventually, coma and death. Organisms of the M. avium complex were cultured from several sites. Histopathologically, the central nervous system lesions consisted of small aggregates of lymphocytes and macrophages containing acid-fast organisms present in a predominantly perivascular location. In view of the life-threatening nature and potential treatability of this uncommon presentation of M. avium complex infection, we suggest that these organisms be sought in immunocompromised patients presenting with unexplained central nervous system symptoms.

Autosomal recessive neurodegenerative disorder with trichorrhexis invaginata and ectodermal dysplasia

Two siblings are reported with an autosomal recessive syndrome characterized by hair and skin abnormalities, hypoplastic nails, generalized hypotonia, absent reflexes, and progressive neurologic deterioration. Although this disorder shares clinical features with an ectodermal dysplasia syndrome with neurodegenerative changes, no specific neuropathologic findings were present. Instead, trichorrhexis invaginata was found in some hair shafts. Hair analysis may be helpful in classifying clinically confusing neurologic conditions.