Local Lung Mass Masquerading a Very Aggressive Extraskeletal Ewing Sarcoma Presenting as Bilateral Paraparesis in a Young Adult

Abstract

Ewing sarcoma is typically seen in children involving long bones. Although well described, its presentation in extraskeletal tissues is relatively rare and is classified as an Ewing sarcoma family of tumors. They are mostly curable when they occur in children. An extraskeletal Ewing sarcoma in adults is uncommon, limiting the experience in adult oncologists. The biopsy is essential for definitive diagnosis, which shows small round blue cells that must be differentiated from lymphoma, embryonal rhabdomyosarcoma, and small cell carcinoma. Management is multimodal, involving surgery, radiation for local treatment of primary tumor, and systemic chemotherapy. A multidisciplinary approach, coupled with risk-adapted intensive neoadjuvant and adjuvant multi-agent chemotherapies and other modalities such as radiation and surgery for control of the primary site and metastatic disease, is needed. The primary multidrug chemotherapy regimen consists of alternating cycles of vincristine/doxorubicin/cyclophosphamide (VDC) and ifosfamide/etoposide (IE) given every 2 weeks with growth factor support. Prognosis and the 5-year survival rate are better for localized than the metastatic disease, and in metastatic disease, it is better for patients with lung metastasis than other metastatic disease sites. We describe a rare extraskeletal tumor arising from a lung that tested positive for Ewing sarcoma, also known as Askins tumor in a young adult. In our case, the tumor rapidly metastasized locally to involve the thoracic spine causing paraparesis. Timely diagnosis and early management are essential to improve outcomes. We also present how treatment can be delayed due to sepsis and emphasize the careful multispecialty approachs importance.

J Med Cases. 2020;11(12):388-393
doi: https://doi.org/10.14740/jmc3582