Recurrent Leiomyosarcoma With Malignant Transformation

Abstract

The soft tissues are comprised of various structures and supportive tissues in the body, including muscle, connective tissues, endothelium, synovium, fat, lymphatics, and fascia. Soft tissue sarcomas may arise in any part of the body. The most common sites are the trunk and the extremities. Fibrosarcoma is the most common non-rhabdomyosarcoma soft tissue sarcoma (NRSTS) in children, in whom two peaks in incidence are observed. The first is in children younger than five years, and the second is in children and adolescents aged 10-15 years. Infantile fibrosarcoma (IFS) is almost exclusively observed in children younger than two years. Many of these sarcomas are congenital. This tumor is locally aggressive, but rarely metastatic, and occurs in the extremity in 70% of patients. A 29-year-old lady presented to the Oncology unit with the fifth recurrence of fibrosarcoma which was transformed into very vascular and high-grade leiomyosarcoma from the fourth recurrence onwards. Initially, it was diagnosed when she was two days old and radiologically diagnosed as lymphangioma. It was documented as a large lump at the right lumbar region with uniform echogenicity and was excised and the postoperative period was uneventful. At the age of 12 years, she presented with a large mass at the right lumbar region over the surgical scar and complete excision done with R0 resection. Histology revealed well-differentiated fibrosarcoma with varying sizes of fibroblasts and no alignment features. The third relapse was at the age of 27. Complete excision was done and histology reported as spinel cell tumor with the possibility of fibrosarcoma or leiomyosarcoma. It was R0 resection and adjuvant treatment was not offered. Tumour recurred over the same scar within a year. Since the tumor is very big with 10 cm craniocaudal and 9 cm wide neoadjuvant chemotherapy is given: IV doxorubicin and IV cisplatin. Surgery was performed after four cycles and found necrotic tissue only. There were no tumor tissues or any form of spindle cells. Due to the aggressive nature, there was no exact solid tumor to assess margins for recommended adjuvant radiotherapy; IMRT. Due to the delay in finding a spacer to keep the bowel away from the radiotherapy field, radiotherapy was delayed and the tumor recurred within six months. It was a radiologically very vascular tumor and she had severe neuropathy and autotoxicity and could not offer any more chemotherapy. The tumor was rapidly growing and was bigger than the last time. Tumor growth was controlled with antiangiogenesis inhibitor; IV bevacizumab and high dose steroids and opioids for pain. After four months, we could not continue bevacizumab due to very high blood pressure and the patient died while waiting for palliative surgery. Childhood fibrosarcoma, including IFS, has classically been treated with surgery alone or with neoadjuvant chemotherapy and surgery. In cases that are not amenable, surgical resection is done upfront. Patients with IFS have an excellent prognosis, with survival rates of more than...