A case report of concurrent embryonal rhabdomyosarcoma and diffuse large B-cell lymphoma in an adult without identifiable cancer predisposition.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is the most common form of non-Hodgkin lymphoma. Rhabdomyosarcoma, the most common soft tissue sarcoma of childhood. makes up less than 1% of solid malignancies in adults with around 400 new cases each year in the United States. They have not previously been reported concurrently. CASE PRESENTATION: A 37 year old woman presented with painful enlarging leg mass. Biopsy of the mass was consistent with embryonal rhabdomyosarcoma. Staging imaging revealed a PET avid anterior mediastinal lymph node. Excisional biopsy of this mass was consistent with diffuse large B-cell lymphoma. Hybridization capture-based next-generation DNA sequencing did not reveal shared somatic tumor mutations. Germline analysis did not show identifiable aberrations of TP53 or other heritable cancer susceptibility genes. She was treated with a personalized chemotherapy regimen combining features of R-CHOP and Children's Oncology Group ARST 0331. CONCLUSIONS: This case illustrates a unique clinical entity successfully treated with a personalized chemotherapeutic regimen.

Recurrent osteosarcoma with a single pulmonary metastasis: a multi-institutional review.

BACKGROUND: Late relapse and solitary lesion are positive prognostic factors in recurrent osteosarcoma. METHODS: We reviewed the records of 39 patients treated at three major centres for recurrent osteosarcoma with a single pulmonary metastasis more than 1 year after diagnosis. We analysed their outcomes with respect to clinical factors and treatment with chemotherapy. RESULTS: Median age at diagnosis was 14.6 years. Relapse occurred at a median of 2.5 years (range, 1.2-8.2 years) after initial diagnosis. At relapse, all patients were treated by metastasectomy; 12 (31%) patients also received chemotherapy. There was no difference in time to recurrence or nodule size between the patients who received or did not receive chemotherapy at relapse. Sixteen patients had no subsequent recurrence, 13 of whom survive without evidence of disease. The 5-year and 10-year estimates of post-relapse event-free survival (PREFS) were 33.0±7.5% and 33.0±9.6%, respectively, and of post-relapse survival (PRS) 56.8±8.6% and 53.0±11.0%, respectively. There was a trend for nodules <1.5 cm to correlate positively with PREFS (P=0.070) but not PRS (P=0.49). Chemotherapy at first relapse was not associated with PREFS or PRS. CONCLUSION: Approximately half of the patients with recurrent osteosarcoma presenting as a single pulmonary metastasis more than 1 year after diagnosis were long-term survivors. Metastasectomy was the primary treatment; chemotherapy did not add benefit.

The actin-cytoskeleton linker protein ezrin is regulated during osteosarcoma metastasis by PKC.

Ezrin is a member of the ERM (ezrin, radixin, moesin) protein family and links F-actin to the cell membrane following phosphorylation. Ezrin has been associated with tumor progression and metastasis in several cancers including the pediatric solid tumors, osteosarcoma and rhabdomyosarcoma. In this study, we were surprised to find that ezrin was not constitutively phosphorylated but rather was dynamically regulated during metastatic progression in osteosarcoma. Metastatic osteosarcoma cells expressed phosphorylated ERM early after their arrival in the lung, and then late in progression, only at the invasive front of larger metastatic lesions. To pursue mechanisms for this regulation, we found that inhibitors of PKC (protein kinase C) blocked phosphorylation of ezrin, and that ezrin coimmunoprecipitated in cells with PKCalpha, PKCiota and PKCgamma. Furthermore, phosphorylated forms of ezrin and PKC had identical expression patterns at the invasive front of pulmonary metastatic lesions in murine and human patient samples. Finally, we showed that the promigratory effects of PKC were linked to ezrin phosphorylation. These data are the first to suggest a dynamic regulation of ezrin phosphorylation during metastasis and to connect the PKC family members with this regulation.