Unusual sites of extraskeletal metastases of Ewing sarcoma after allogeneic hematopoietic stem cell transplantation

Abstract

Allogeneic stem cell transplantation (SCT) for solid tumors remains under investigation. We report a case of extended disease stability after a nonmyeloablative peripheral blood SCT for metastatic, refractory Ewing sarcoma. Of note, the patient developed metastatic disease to 2 unusual sites-the brain and small intestine. The allogeneic SCT environment may alter typical metastatic patterns, and may represent an ideal platform to manipulate and enhance the antitumor immune response. Further clinical trials are needed to evaluate the role for allogeneic SCT for this disease.

Figures

Figure 1

Pulmonary metastases to the left hilum and left lower lobe as shown by chest CT post-contrast, (A) starting at initial recurrence, and (B) at pre-SCT restaging after 4 cycles of cyclophosphamide and topotecan. (C) Followed over the length of the SCT, a substantial period of disease stability is noted when examining the longest diameter of the pulmonary lesions. (D) Immune reconstitution of T cells (CD3+, CD4+ and CD8+), CD20+ B cells and CD16+ CD56+ natural killer cells during the SCT period as determined by flow cytometry of peripheral blood lymphocytes. (E) Immune reconstitution of memory CD4+ T cells (CD45RO+), naïve CD4+ T cells (CD45RA+ CD62L+), memory CD8+ T cells (CD45RO+), and naïve CD8+ T cells (CD28+ CD57+) during the SCT period as determined by flow cytometry of peripheral blood lymphocytes.

Figure 2

Ewing sarcoma metastases (A) to the left parietal lobe and right occipital lobe as visualized by MRI T2 post-FLAIR, (B) serving as a lead point for an ileocecal intussusception seen by abdominal CT post-contrast (C), and during exploratory laparotomy.