gdc-0973 and Rhabdomyosarcoma

Undifferentiated sarcoma has been hypothesized as an intermediate step in the progression of malignant melanoma to rhabdomyosarcoma. The current report describes a new case of rhabdomyosarcomatous transformation in a malignant melanoma and documents the temporal progression of the malignant melanoma to rhabdomyosarcoma in different metastatic sites via undifferentiated sarcoma. A 65-year-old female with a past medical history of malignant melanoma presented with a new lung mass. A core biopsy revealed a malignant spindle cell neoplasm that was negative for all melanocytic markers, suggesting the possibility of a primary pulmonary sarcomatoid carcinoma or sarcoma. The subsequent lobectomy demonstrated an undifferentiated spindle cell neoplasm with areas of rhabdomyoblastic differentiation. Review of the skin lesion and lymph nodes confirmed the diagnosis of the primary cutaneous malignant melanoma, but also revealed that the nodal metastases had largely transformed into an undifferentiated sarcoma with similar morphology as the spindle cell neoplasm in the lung. Molecular studies demonstrated an identical

Topics: Aged; Antineoplastic Combined Chemotherapy Protocols; Azetidines; Biomarkers, Tumor; Cell Transformation, Neoplastic; Diagnosis, Differential; Disease Progression; Drug Resistance, Neoplasm; Female; Humans; Lung; Lung Neoplasms; Melanoma; Neoadjuvant Therapy; Piperidines; Pneumonectomy; Proto-Oncogene Proteins B-raf; Rhabdomyosarcoma; Skin; Skin Neoplasms; Vemurafenib