The Oncolytic Activity of Zika Viral Therapy in Human Neuroblastoma In Vivo Models Confers a Major Survival Advantage in a CD24-dependent Manner.

Neuroblastoma is the most common extracranial tumor, accounting for 15% of all childhood cancer-related deaths. The long-term survival of patients with high-risk tumors is less than 40%, and MYCN amplification is one of the most common indicators of poor outcomes. Zika virus (ZIKV) is a mosquito-borne flavivirus associated with mild constitutional symptoms outside the fetal period. Our published data showed that high-risk and recurrent neuroblastoma cells are permissive to ZIKV infection, resulting in cell type-specific lysis. In this study, we assessed the efficacy of ZIKV as an oncolytic treatment for high-risk neuroblastoma using in vivo tumor models. Utilizing both MYCN-amplified and non-amplified models, we demonstrated that the application of ZIKV had a rapid tumoricidal effect. This led to a nearly total loss of the tumor mass without evidence of recurrence, offering a robust survival advantage to the host. Detection of the viral NS1 protein within the tumors confirmed that a permissive infection preceded tissue necrosis. Despite robust titers within the tumor, viral shedding to the host was poor and diminished rapidly, correlating with no detectable side effects to the murine host. Assessments from both primary pretreatment and recurrent posttreatment isolates confirmed that permissive sensitivity to ZIKV killing was dependent on the expression of CD24, which was highly expressed in neuroblastomas and conferred a proliferative advantage to tumor growth. Exploiting this viral sensitivity to CD24 offers the possibility of its use as a prognostic target for a broad population of expressing cancers, many of which have shown resistance to current clinical therapies. SIGNIFICANCE: Sensitivity to the tumoricidal effect of ZIKV on high-risk neuroblastoma tumors is dependent on CD24 expression, offering a prognostic marker for this oncolytic therapy in an extensive array of CD24-expressing cancers.

Rhabdomyosarcoma With Diffuse Bone Marrow Metastases.

Rhabdomyosarcoma is a highly aggressive cancer that is generally considered a disease of childhood. A vast majority of cases occur in those below the age of 20. Rhabdomyosarcoma can occur in any soft tissue in the body but is primarily found in the head, neck, orbit, genitourinary tract, genitals, and extremities. Prognosis is closely tied to the location of the primary tumor and the extent of metastatic spread. As with most sarcomas, rhabdomyosarcoma has a pattern of hematogenous spread which favors metastasis to the lungs. Other common areas include bone marrows, liver, breasts, and brain. One unusual pattern is the presence of diffuse bone marrow metastases in absence of significant soft tissue disease other than primary (no distant nodal disease, absence of visceral disease in chest and abdomen). Frequently in such cases, patients may have initial presentation similar to hematologic malignancy especially when the primary tumor is not evident. This pattern has been rarely described in the radiology literature. This pattern appears to be well documented in pathology literature. Even more rarely, in some cases, the primary tumor site may not be found after imaging and may remain undetermined even postmortem - only diagnosed by bone marrow aspiration. Awareness of this unique pattern is clearly important for radiologists, especially pediatric radiologists, as misdiagnosis can lead to delay in appropriate treatment that ultimately results in increased mortality. We present a case of rhabdomyosarcoma with this unique pattern of bone marrow metastases in which initial differential diagnosis favored a leukemic picture. This paper will go over the diagnostic techniques utilized throughout our patient's disease course as well as treatment.

Congenital Mastocytosis: Case Report and Review of the Literature.

Mastocytosis is a rare infiltrative disorder characterized by mast cell proliferation within the skin and various extra-cutaneous organ systems. We report the case of a full-term neonate admitted to the neonatal intensive care unit for evaluation of diffuse skin lesions on her face, trunk and extremities. Initially, the lesions appeared to be consistent with a blueberry muffin rash. However, over a period of days the lesions became vesicular and changed in shape and number. The neonate underwent evaluation for infective etiologies, skin biopsy of the lesions, and flow cytometry analysis of the peripheral blood. The surgical pathology examination of the skin biopsy demonstrated mast cells consistent with a diagnosis of cutaneous mastocytosis. A review of relevant literature is also provided.

Mature Teratoma Confined to the Posterior Fossa.

Mature teratomas located solely in the posterior fossa are rare. We describe a girl who presented with hydrocephalus caused by a posterior fossa tumor that was ultimately diagnosed as a mature teratoma following complete extirpation. Unusual imaging characteristics which produced confusion preoperatively were, however, very consistent with mature teratomas that are encountered in the gonads. Immature elements were universally absent; therefore, extirpation was curative. Hydrocephalus is unlikely to resolve after tumor removal, and cerebrospinal fluid diversion may be required.

Granulocytic sarcoma of pediatric head and neck: an institutional experience.

OBJECTIVE: To demonstrate a case series of granulocytic sarcoma of the head and neck found in the pediatric population and review long-term outcomes. METHODS: A pathology database at a tertiary hospital was searched for patients with biopsy specimens from the head and neck diagnosed as granulocytic sarcoma. RESULTS: There were 6 cases between 1992 and 2004 that met inclusion criteria. Subjects' age ranged from 22 months to 14 years old. In three cases, the patients were diagnosed with acute myeloid leukemia (AML) based on biopsy results; 2 patients were already diagnosed with AML when diagnosed with granulocytic sarcoma, and in 1 case, a relapse of AML was diagnosed. In all cases, patients began induction chemotherapy. Two patients died during induction chemotherapy from infection. The remaining 4 patients underwent bone marrow transplants. One patient had a relapse post-transplant and died. Only one patient was healthy two years post-transplant. CONCLUSION: The results of this series suggest granulocytic sarcoma must be on the differential when tumors present in the head and neck region in pediatric patients. In our series, 100% of the patients with granulocytic sarcoma had underlying AML. The long-term prognosis of patients with AML who developed granulocytic sarcoma is quite poor.

Fatal Naegleria fowleri infection acquired in Minnesota: possible expanded range of a deadly thermophilic organism.

BACKGROUND: Primary amebic meningoencephalitis (PAM), caused by the free-living ameba Naegleria fowleri, has historically been associated with warm freshwater exposures at lower latitudes of the United States. In August 2010, a Minnesota resident, aged 7 years, died of rapidly progressive meningoencephalitis after local freshwater exposures, with no history of travel outside the state. PAM was suspected on the basis of amebae observed in cerebrospinal fluid. METHODS: Water and sediment samples were collected at locations where the patient swam during the 2 weeks preceding illness onset. Patient and environmental samples were tested for N. fowleri with use of culture and real-time polymerase chain reaction (PCR); isolates were genotyped. Historic local ambient temperature data were obtained. RESULTS: N. fowleri isolated from a specimen of the patient's brain and from water and sediment samples was confirmed using PCR as N. fowleri genotype 3. Surface water temperatures at the times of collection of the positive environmental samples ranged from 22.1°C to 24.5°C. August 2010 average air temperature near the exposure site was 25°C, 3.6°C above normal and the third warmest for August in the Minneapolis area since 1891. CONCLUSIONS: This first reported case of PAM acquired in Minnesota occurred 550 miles north of the previously reported northernmost case in the Americas. Clinicians should be aware that N. fowleri-associated PAM can occur in areas at much higher latitude than previously described. Local weather patterns and long-term climate change could impact the frequency of PAM.

Pediatric tracheal and endobronchial tumors: an institutional experience.

OBJECTIVES: To report the pathologic findings in cases involving endotracheal and endobronchial tumors in the pediatric population and to describe the presenting symptoms and treatment modalities for endotracheal and endobronchial tumors. DESIGN: Retrospective chart review. SETTING: Tertiary care children's hospital. PATIENTS: The study included 14 patients with endotracheal and endobronchial tumors. MAIN OUTCOME MEASURES: Patients were selected if bronchoscopy was performed to obtain biopsy specimens from the trachea or bronchus. RESULTS: There were 14 cases that met the inclusion criteria between 1993 and 2009. The patients ranged in age from 4 to 18 years. The most common presenting symptom was recurrent pneumonia (n = 6), followed by wheezing or asthma that was unresponsive to treatment (n = 4). Nine lesions (64%) were malignant and 5 (36%) were benign. Of the malignant tumors, 5 (55%) were carcinoid, 3 (33%) were mucoepidermoid carcinoma, and 1 was adenoid cystic carcinoma. There were 1 or 2 cases of each of the following benign to intermediate malignant potential lesions: histoplasmosis nodules, chondroid hamartoma, pulmonary chondroma, and inflammatory myofibroblastic tumor. In 12 cases, definitive treatment included surgical resection. Three of these cases required postoperative chemotherapy and radiotherapy. CONCLUSIONS: The results of this series suggest that in the pediatric population tracheal and endobronchial tumors are most likely to be carcinoid tumors or mucoepidermoid carcinomas, both malignant processes. For patients with recurrent pneumonias or chronic wheezing, an occult tumor is a diagnostic consideration that may require additional studies.