The Pathologic Diagnosis of Pediatric Soft Tissue Tumors in the Era of Molecular Medicine: The Sarcoma Pediatric Pathology Research Interest Group Perspective.

Context.—: Pediatric soft tissue tumors are one of the areas of pediatric pathology that frequently generate consult requests. Evolving classification systems, ancillary testing methods, new treatment options, research enrollment opportunities, and tissue archival processes create additional complexity in handling these unique specimens.

Magnetic resonance and computed tomography imaging features of epithelioid sarcoma in children and young adults with pathological and clinical correlation: a report from Children's Oncology Group study ARST0332.

Objective: To correlate imaging features of epithelioid sarcoma in children and young adults enrolled in Children's Oncology Group study ARST0332 with clinical and pathological findings.

Materials And Methods: Fifteen patients (6 males; median age 16.1 years, range 6.

Undifferentiated Sarcomas in Children Harbor Clinically Relevant Oncogenic Fusions and Gene Copy-Number Alterations: A Report from the Children's Oncology Group.

A comprehensive analysis of the genomics of undifferentiated sarcomas (UDS) is lacking. We analyzed copy-number alterations and fusion status in patients with UDS prospectively treated on Children's Oncology Group protocol ARST0332. Copy-number alterations were assessed by OncoScan FFPE Express on 32 UDS.

Opportunities for Improvement in Pathology Reporting of Childhood Nonrhabdomyosarcoma Soft Tissue Sarcomas: A Report From Children's Oncology Group (COG) Study ARST0332.

Objectives: Treatment of soft tissue tumors in young patients relies on the diagnostic information conveyed in the pathology report. We examined pathology reports from Children's Oncology Group ARST0332 for inclusion of data elements required in published guidelines.

Methods: Pathology reports for 551 eligible patients were examined for required data elements defined by the College of American Pathologists, including tissue type, procedure, tumor site, tumor maximum diameter, macroscopic extent of tumor, histologic type, mitotic rate, extent of necrosis, tumor grade, margin status, use of ancillary studies, and pathologic stage.

The Evolution of Pediatric Soft Tissue Sarcoma Classification in the Last 50 Years.

This review discusses the history of the classification of soft tissue sarcomas in children and adolescents, the current transition toward integration of morphology and molecular genetics as new entities emerge, and future perspectives.

Radiation-induced Sarcomas Occurring in Desmoid-type Fibromatosis Are Not Always Derived From the Primary Tumor.

Desmoid-type fibromatosis is a rare, highly infiltrative, locally destructive neoplasm that does not metastasize, but recurs often after primary surgery. Activation of the Wnt/β-catenin pathway is the pathogenic mechanism, caused by an activating mutation in exon 3 of CTNNB1 (85% of the sporadic patients). Radiotherapy is a frequent treatment modality with a local control rate of approximately 80%.

Imaging features of alveolar soft-part sarcoma: a report from Children's Oncology Group Study ARST0332.

Objective: There are few studies in the literature regarding the imaging features of alveolar soft-part sarcoma (ASPS). We performed a comprehensive assessment of the imaging characteristics of this rare tumor to determine whether there are features that suggest the diagnosis.

Materials And Methods: Twenty-two subjects with ASPS underwent pretherapy imaging as part of enrollment in Children's Oncology Group protocol ARST0332 for the treatment of nonrhabdomyosarcoma soft-tissue sarcomas: 16 patients underwent MRI; three, CT; and three, both MRI and CT.

Desmoid-type fibromatosis-associated Gardner fibromas: prevalence and impact on local recurrence.

Although Gardner fibroma is a precursor lesion of desmoid tumor, the prevalence and prognostic importance of Gardner fibroma associated with desmoid tumors has not been systematically studied in adults. From 129 patients with desmoid-type fibromatosis, 170 specimens were re-examined for the presence of an associated Gardner fibroma. Clinicopathologic features of Gardner fibroma-associated desmoid-type fibromatosis were compared to desmoid tumors without associated Gardner fibroma.

Inflammatory myofibroblastic tumors harbor multiple potentially actionable kinase fusions.

Unlabelled: Inflammatory myofibroblastic tumor (IMT) is a neoplasm that typically occurs in children. The genetic landscape of this tumor is incompletely understood and therapeutic options are limited. Although 50% of IMTs harbor anaplastic lymphoma kinase (ALK) rearrangements, no therapeutic targets have been identified in ALK-negative tumors.

Alveolar soft part sarcoma and granular cell tumor: an immunohistochemical comparison study.

Although the histologic features of alveolar soft part sarcoma and granular cell tumor are typically distinctive, occasional cases show a significant morphologic overlap. Differentiating these entities is crucial because granular cell tumor is almost always benign and alveolar soft part sarcoma is invariably malignant. We evaluated a panel of immunohistochemical stains (S-100 protein, inhibin, SOX10, nestin, calretinin, and TFE3) in 13 alveolar soft part sarcomas and 11 granular cell tumors.

Fibrous hamartoma of infancy: a clinicopathologic analysis of 60 cases.

Fibrous hamartoma of infancy is a benign soft tissue tumor with a characteristic triphasic organoid histologic appearance. It typically occurs within the first 2 years of life. The usual anatomic locations include the upper extremities, axilla, and upper back.

Survivin expression and prognostic significance in pediatric malignant peripheral nerve sheath tumors (MPNST).

Malignant peripheral nerve sheath tumors (MPNST) are very aggressive malignancies comprising approximately 5-10% of all soft tissue sarcomas. In this study, we focused on pediatric MPNST arising in the first 2 decades of life, as they represent one the most frequent non-rhabdomyosarcomatous soft tissue sarcomas in children. In MPNST, several genetic alterations affect the chromosomal region 17q encompassing the BIRC5/SURVIVIN gene.

Syndrome-associated soft tissue tumours.

Soft tissue neoplasms may be associated with a variety of genetic disorders and malformation syndromes, especially when they arise in children, adolescents and early adulthood. This review summarizes the principal histopathological types of soft tissue tumours which occur in various syndromes, with an emphasis on pathological features, genetic aspects and considerations for the diagnostic pathologist.

Plexiform fibromyxoma: report of two pediatric cases and review of the literature.

Plexiform fibromyxoma is a distinctive mesenchymal neoplasm usually arising in the gastric antrum. We report 2 cases of this entity in pediatric patients, including the first case arising in the esophagus. The patients were a 16-year-old female who presented with chest pain and was found on computed tomographic scan to have a midesophageal mass at the level of the carina, and an 11-year-old female with a gastric mass.

Myxoinflammatory fibroblastic sarcoma in children and adolescents: clinicopathologic aspects of a rare neoplasm.

Myxoinflammatory fibroblastic sarcoma (MIFS), originally described as a low-grade malignant soft-tissue tumor in adults, has recently been reported in children and in non-acral sites. This report describes the clinicopathologic features of a series of 5 MIFS in children and adolescents (3 males, 2 females), ranging in age from 5 to 17 years (mean, 13 years). These tumors presented as small, superficial, slowly growing soft-tissues masses of the scalp, neck, middle finger, forearm, and thigh.

Predicting dedifferentiation in liposarcoma: a proteomic approach.

There are no known morphologic characteristics, cytogenetic aberrations, or molecular alterations predictive of dedifferentiation in liposarcomas. Identification of such a prognostic marker could potentially affect surgical and adjuvant therapy and/or follow-up surveillance for these patients. Two-dimensional difference gel electrophoresis was utilized to characterize protein expression patterns in lipoma, atypical lipomatous tumor (ALT), and the well-differentiated components of dedifferentiated liposarcoma (DDL).

Composite uterine neoplasm with embryonal rhabdomyosarcoma and primitive neuroectodermal tumor components: rhabdomyosarcoma with divergent differentiation, variant of primitive neuroectodermal tumor, or unique entity?

Three cases of composite uterine neoplasms comprised of primitive neuroectodermal tumor (PNET) and rhabdomyosarcoma (RMS) have previously been described, including only one wherein the rhabdomyosarcomatous component was of the embryonal subtype. Whether such composite neoplasms are a variant of RMS, a variant of PNET, or a unique entity is unknown. We report the clinicopathologic, immunohistochemical, and molecular cytogenetic findings in a case of uterine embryonal RMS with coexisting PNET that was diagnosed in a 25-year-old female.

Signal transduction pathway analysis in desmoid-type fibromatosis: transforming growth factor-β, COX2 and sex steroid receptors.

Despite reports of sex steroid receptor and COX2 expression in desmoid-type fibromatosis, responses to single agent therapy with anti-estrogens and non-steroidal anti-inflammatory drugs are unpredictable. Perhaps combination pharmacotherapy might be more effective in desmoid tumors that co-express these targets. Clearly, further understanding of the signaling pathways deregulated in desmoid tumors is essential for the development of targeted molecular therapy.

Nuclear p63 expression in osteoblastic tumors.

Expression of the p63 tumor suppressor protein has been reported in the mononuclear stromal cells of giant cell tumor of the bone, which may represent osteoblast-precursor cells. Only a limited number of osteoblastic tumors have been studied for p63 expression thus far. We therefore examined whether p63 may serve as a marker for osteoblastic differentiation in osteosarcomas or as a differential diagnostic marker to distinguish osteoblastoma from osteosarcoma.

Soft tissue tumors of uncertain origin.

Many soft tissue tumors of childhood lack obvious differentiation toward a defined mesenchymal tissue type or have a phenotype that does not correspond to any defined normal tissue. These challenging tumors are currently regarded as neoplasms of uncertain differentiation. Nonetheless, there have been great strides in the understanding of their pathologic and genetic features and biologic underpinnings.