Composite Neuroblastoma Metastatic to a Lymph Node: The Novel Histopathologic Diagnosis of a Unique Multiclonal Neoplasm.

OBJECTIVE: Composite neuroblastoma is a tumor composed of multiple tumoral clones within the neuroblastoma family. To date, establishing this unique histopathologic diagnosis has required the evaluation of the primary tumor mass. We report a case of composite neuroblastoma diagnosed by evaluation of a metastatic lymph node. METHODS: One abdominal lymph node involved by tumor was evaluated in a 6-year-old boy. The primary abdominal mass was not examined. Following histopathologic examination, clonality studies using comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH) were also performed. RESULTS: Two distinct tumor components were identified by histopathologic evaluation and classified as differentiating neuroblastoma (component A) and poorly differentiated neuroblastoma (component B). Based on the patient's age, each clone was further classified as Unfavorable Histology. The presence of these two different tumoral clones was confirmed by CGH and FISH. CONCLUSION: This case affirms the histopathologic approach to evaluating composite tumors, as established by the International Neuroblastoma Pathology Classification (INPC) model for ganglioneuroblastoma, nodular tumors. Also, when both components are metastatic, this case demonstrates that composite tumors can be diagnosed by the evaluation of metastatic lesions alone. Finally, it supports the addition of composite neuroblastoma to a future version of the INPC.

Sclerosing Epithelioid Fibrosarcoma of the Kidney: First Reported Case in a Young Child.

Sclerosing epithelioid fibrosarcoma (SEF) is a rare variant of fibrosarcoma primarily arising in the deep soft tissue of the extremities and trunk. Despite having the morphologic appearance of a low-grade sarcoma, it generally has an aggressive clinical course with frequent local recurrences and distant metastases. It typically occurs in middle aged adults and is characterized by immunoexpression of MUC4 and recurrent gene fusions, most commonly EWSR1-CREB3L1. We report a primary renal SEF in a 4-year-old male. To our knowledge, this is the youngest patient reported with SEF and the second case of SEF in a pre-adolescent child. It is the eleventh reported case of primary renal SEF in the literature. While SEF arising in visceral organs is rare, the kidney is the most common primary site of any visceral organ. This case demonstrates SEF can occur in pre-adolescents, is an important consideration when evaluating sarcomas in young children, and should be considered in the differential diagnosis for primary renal tumors.

An unusual presentation of primary pulmonary extranodal marginal zone lymphoma of mucosal associated lymphoid tissue: An autopsy case report.

A 40 year old female with no documented medical history presented to the Emergency Department with several days of lethargy and altered mental status. She was found to be anemic, thrombocytopenic, and hypotensive. The patient was found to be in severe metabolic acidosis, became bradycardic, and quickly deteriorated. Clinicians suspected thrombotic thrombocytopenic purpura, and the diagnosis was supported by ADAMTS13 testing. The clinicians attempted to place a Quinton catheter for emergent plasmapheresis, but the patient expired before definitive treatment could be initiated. Autopsy was obtained and revealed a right middle lobe consolidation grossly consistent with lymphoid tissue or tumor.