CD43-positive, EWSR1::FLI1 -rearranged Soft Tissue Sarcoma in a Pediatric Patient With History of B-Cell Acute Lymphoblastic Leukemia

Ewing sarcoma is a small round blue cell tumor typically characterized by an EWSR1 rearrangement and expression of CD99 and NKX2.2, without expression of hematopoietic markers such as CD45. CD43 is an alternative hematopoietic immunohistochemical marker often utilized in the workup of these tumors and its expression typically argues against Ewing sarcoma. We report a 10-year-old with history of B-cell acute lymphoblastic leukemia presenting with an unusual malignant shoulder mass with variable CD43 positivity, but with an EWSR1::FLI1 fusion detected by RNA sequencing. Her challenging workup highlights the utility of next-generation DNA-based and RNA-based sequencing methods in cases with unclear or conflicting immunohistochemical results.

Computational fluid dynamics modeling aiding surgical planning in a toddler with Parkes Weber syndrome

Parkes Weber syndrome is a fast-flow and slow-flow vascular anomaly with limb overgrowth that can lead to congestive heart failure and limb ischemia. Current management strategies have focused on symptom management with focal embolization. A pediatric case with early onset heart failure is reported. We discuss the use of computational fluid dynamics (CFD) modeling to guide a surgical management strategy in a toddler with an MAP2K1 mutation.

Pediatric Tumor Management: Current and Controversial

Bone and soft-tissue tumors are common in the pediatric population. It is important to be familiar with the appropriate workup, principles of biopsy, differences between unicameral and aneurysmal bone cysts, and principles of managing pathologic fractures in children. The management approach to pediatric soft-tissue masses and some of the recent advances in the field warrant discussion.

Soft Tissue Sarcoma Response to Two Cycles of Neoadjuvant Chemotherapy: A Multireader Analysis of MRI Findings and Agreement with RECIST Criteria and Change in SUVmax

RATIONALE AND OBJECTIVES

When soft tissue sarcomas are treated with neoadjuvant chemotherapy, the number of cycles of chemotherapy is usually dependent on the tumor's initial response. Popular methods to assess tumor response include Response Evaluation Criteria in Solid Tumors (RECIST) criteria, which rely solely on tumor size, and maximum standardized uptake value (SUVmax) reduction in positron emission tomography (PET), which requires an expensive and high radiation test. We hypothesized that contrast-enhanced magnetic resonance imaging (MRI) may offer a good alternative by providing additional information beyond tumor size.

MATERIALS AND METHODS

Following IRB approval, a retrospective review identified patients with soft tissue sarcomas who underwent both PET and MRI before and after two cycles of neoadjuvant chemotherapy. Five readers independently examined the MRI exams for: changes in size, T2 or T1 signal, necrosis and degree of enhancement. Readers then made a subjective binary assessment of tumor response to therapy. Each reader repeated the anonymized randomized reading at least 2 weeks apart. 18 F-FDG PET exams were interpreted by a nuclear medicine specialist. The maximum standardized uptake values (SUVmax) for pre and post-chemotherapy exams were compared. Intra- and inter-reader agreement was assessed using Cohen's kappa and Light's kappa, respectively. .

RESULTS

Twenty cases were selected for this multireader study, of which 9 (45%) were responders and 11 were nonresponders by SUVmax. Using all MRI criteria, 43% were classified as responders based on MRI and 1.5% were classified as responders by RECIST criteria. Using PET as the reference, the sensitivity and the specificity of the MRI diagnosis for response using all findings were 50% and 63%, respectively. There was fair to moderate intrareader (kappa = 0.37) and inter-reader (kappa = 0.48) agreement for the MRI diagnosis of response. None of the individual MRI signal characteristics were significantly different between the PET responders and nonresponders. Additionally, no MRI findings were significantly different between those with and without good clinical responses.

CONCLUSION

By our assessment, there is a poor correlation between tumor response by RECIST criteria and PET SUVmax. In addition, varying MR features did not help in diagnosing tumor response. Imaging of tumor response remains a challenging area that requires further research.

[Schönlein-Henoch syndrome]

Schönlein-Henoch's syndrome is particularly seen between the ages of two and eight years and is twice as frequent in boys as in girls. In up to 80%, symptoms in the form of skin rash, arthritis and abdominalia are observed. The pathognomonic symptom is the skin lesion which most often is confined to the region below the waist and is the first symptom in more than 50%. Incorrect diagnosis particularly of abdominal symptoms may result in unnecessary laparotomy. The etiology and pathogenesis are not yet completely elucidated but it is believed that SHS is caused by an IgA-mediated immune response to a variety of foreign antigens. The treatment and the prophylaxis, particularly concerning the nephropathy, of SHS is still very deficient today. Depending on the nature and the degree of difficulty the treatment is: salicylates, NSAID, prednisone, cytotoxica, plasmapheresis, substitution with factor 13-concentrate and, in terminal renal failure, allotransplantation renis. The course and the prognosis is usually good in cases without nephropathy. In mild cases, the disease lasts a few days, in more serious cases 4-6 weeks with subsequent exacerbations and remissions. Patients who have had SHS-nephritis ought to be followed for at least five years with an annual examination of the blood pressure and urine test for protein and blood. SHS ought to be considered as differential diagnosis in acute cases of abdominal pains, arthralgia, hematuria and CNS-symptoms even if the characteristic skin symptoms are missing.