Primitive myxoid mesenchymal tumor of infancy: a clinicopathologic report of 6 cases.
ABSTRACT Soft tissue sarcomas in the first year of life are rare, and the most common sarcomas in infancy are embryonal rhabdomyosarcoma, Ewing sarcoma/primitive neuroectodermal tumor, congenital infantile fibrosarcoma, and primitive sarcomas such as undifferentiated sarcoma. In this study, we report 6 cases of a primitive myxoid mesenchymal tumor of infancy (PMMTI), which previously may have been included under the diagnostic categories of congenital-infantile fibrosarcoma or infantile fibromatosis. PMMTI occurred in 6 infants, 3 of whom had a congenital presentation of a soft tissue mass. All patients were otherwise healthy. The tumors occurred on the trunk, extremities, and head and neck. Grossly, the tumors were nonencapsulated and had a multinodular appearance with focal infiltrative growth, a white fleshy cut surface, and a tumor diameter ranging from 2 to 15 cm. Histologically, a diffuse growth of primitive spindle, polygonal, and round cells occurred in a myxoid background. The tumor cells were arranged in a vaguely nodular pattern with peripheral collagenized stroma, higher cellularity at the periphery, and a delicate vascular network in the background. Immunohistochemically, the tumors displayed diffuse reactivity for vimentin and no reactivity for smooth muscle actin, muscle specific actin, desmin, S-100 protein, or myogenin. Electron microscopy documented a poorly differentiated fibroblastic proliferation. Four cases tested negative for the ETV6-NTRK3 gene fusion by RT-PCR. One tumor had a complex karyotypic abnormality with rearrangements involving chromosomes Y, 9, and 3. Three patients had recurrences or metastasis treated with a combination of surgery and chemotherapy. One patient is alive with persistent locally aggressive disease, 2 are alive with no evidence of recurrence, 1 had a recurrence treated surgically without further follow-up information, 1 patient died with persistent tumor and sepsis 6 weeks after diagnosis, and 1 patient was lost to follow-up. The morphologic appearance combined with the ultrastructural features and absence of the typical gene rearrangement of congenital-infantile fibrosarcoma are unique, and we propose that PMMTI represents a new category of pediatric fibroblastic-myofibroblastic tumor.
[Show abstract] [Hide abstract]
ABSTRACT: Primitive myxoid mesenchymal tumor of infancy is an extremely rare and recently recognized soft tissue tumor entity with a tendency for multiple recurrences. Only ten cases have been described in the literature and most cases are reported in Western countries. This tumor ranges in size from 2 to 15 cm and is characterized microscopically by a diffuse growth of primitive cells in a myxoid background with focal fascicles or a herringbone pattern. In this study, we describe a primitive myxoid mesenchymal tumor of infancy on the scalp of a 3-month-old Taiwanese boy. The histology showed typical morphology and the tumor cells showed vimentin and CD99 immunoreactivities. The translocation t(12,15)(p13;q25) was not found by fluorescence in situ hybridization. After complete surgical excision, no recurrence was noted during an 18-month follow-up.Medical Molecular Morphology 03/2013; DOI:10.1007/s00795-013-0032-1 · 1.07 Impact Factor
Article: Tumoral, quasitumoral and pseudotumoral lesions of the superficial and somatic soft tissue: new entities and new variants of old entities recorded during the last 25 years. Part XII: Appendix Lesioni tumorali, quasitumorali e pseudotumorali delle parti molli somatiche e superficiali: entità nuove e varianti di entità già note, descritte negli ultimi 25 anni. Parte XII: Appendix
Article: Neonatal cancer[Show abstract] [Hide abstract]
ABSTRACT: Neonatal cancer is rare and comprises a heterogeneous group of neoplasms with substantial histological diversity. Almost all types of paediatric cancer can occur in fetuses and neonates; however, the presentation and behaviour of neonatal tumours often differs from that in older children, leading to differences in diagnosis and management. The causes of neonatal cancer are unclear, but genetic factors probably have a key role. Other congenital abnormalities are frequently present. Teratoma and neuroblastoma are the most common histological types of neonatal cancer, with soft-tissue sarcoma, leukaemia, renal tumours, and brain tumours also among the more frequent types. Prenatal detection, most often on routine ultrasound or in the context of a known predisposition syndrome, is becoming more common. Treatment options pose challenges because of the particular vulnerability of the population. Neonatal cancer raises diagnostic, therapeutic, and ethical issues, and management requires a multidisciplinary approach.The Lancet Oncology 12/2013; 14(13):e609-20. DOI:10.1016/S1470-2045(13)70236-5 · 24.73 Impact Factor