A Nonpediatric Extraosseous Ewing Sarcoma of the Pancreas: Differential Diagnosis and Therapeutic Strategies

Abstract

Extraosseous Ewing's sarcoma is a rare and aggressive malignant tumor with a poor prognosis. The pancreas is an extremely uncommon primary site, with only 27 cases that have been published worldwide. We report a 26-year-old female who presented with 5 days of left upper quadrant pain, nausea, and vomiting. On examination, she was anicteric and had epigastric and left upper quadrant tenderness without guarding, rebound tenderness, or a palpable mass. She had slightly elevated serum aminotransferase and lipase levels. Abdominal computerized tomography revealed a multilobulated tumor arising from the body and tail of the pancreas. A biopsy confirmed a small round cell tumor, and immunohistochemistry was positive for CD99 in approximately 70% of the tumor cells. A fluorescence in situ hybridization (FISH) assay showed a 22q12 rearrangement. She was diagnosed with extraosseous Ewing sarcoma of the pancreas and underwent multiagent neoadjuvant chemotherapy followed by surgical resection, but subsequent imaging revealed evidence of systemic disease progression. She chose to go on hospice care and died a few weeks later.

Rare presentation in a rare case of pancreatic extraosseous Ewing’s sarcoma: A case report

“…Patients with localized disease had 60 to 80% overall 5-year survival rates, but below 30% for patients with metastatic disease. [3,8,9] Our patient was diagnosed with localized pancreatic EES. He was treated with surgical resection combined with chemotherapy and radiation therapy.…”

“…In some published reports, EES may also be found in the abdominal cavity and arise from solid organs such as the kidneys, urinary bladder, ovaries, uterus, parotid glands, heart, and lungs. [ 3 , 9 ] In addition to these organs, this type of tumor can also develop in the pancreas, accounting for 0.3% of primary pancreatic neoplasms. [ 3 , 12 ] Aside from the case discussed here, only 26 other reports on pancreatic EES have been published in the literature.…”

“…Patients with localized disease had 60 to 80% overall 5-year survival rates, but below 30% for patients with metastatic disease. [ 3 , 8 , 9 ]…”

“…[9] Most of the time, it is enough to diagnose ES with a core biopsy of the tumor; nevertheless, immunohistochemistry and cytogenetic analysis are essential when differentiating other small round cell tumors such as Wilms' tumor, neuroblastoma, hepatoblastoma, rhabdomyosarcoma, smallcell lymphoma, visceral small-cell neuroendocrine carcinoma, desmoplastic small round cell tumor, pancreatic neuroendocrine tumor, and pancreatoblastoma. [9] Tumors of the ES family show substantially high expression of the cell surface glycoprotein, so immunohistochemistry is helpful in diagnosing this neoplasm. [3,10] This glycoprotein, a product of a pseudo autosomal gene, namely the MIC2 gene (also called CD99 or p30/32 MIC2), is found on the short arm of the X and Y chromosomes of PNETs and ESs cells.…”

“…[1] The diagnosis of ESFT includes a combination of clinical symptoms, histopathology, immunohistochemical features, and cytogenetic analysis. [9] Most of the time, it is enough to diagnose ES with a core biopsy of the tumor; nevertheless, immunohistochemistry and cytogenetic analysis are essential when differentiating other small round cell tumors such as Wilms' tumor, neuroblastoma, hepatoblastoma, rhabdomyosarcoma, smallcell lymphoma, visceral small-cell neuroendocrine carcinoma, desmoplastic small round cell tumor, pancreatic neuroendocrine tumor, and pancreatoblastoma. [9] Tumors of the ES family show substantially high expression of the cell surface glycoprotein, so immunohistochemistry is helpful in diagnosing this neoplasm.…”