Multicystic dedifferentiated retroperitoneal liposarcoma: tumour cyst fluid analysis and implications for management

Abstract

Liposarcomas are soft tissue sarcomas of adipocyte origin. We describe a case of a dedifferentiated retroperitoneal liposarcoma with an unusual presentation on recurrence as a large, multicystic tumour. The patient was a 72-year-old woman who had undergone multiple treatments including two prior resections. For her most recent locoregional disease recurrence, the patient was offered surgical debulking for symptom palliation. At this operation, performed after two cycles of chemotherapy, the tumour cyst fluid was analysed and found to have a predominance of immune cells with no identifiable malignant cells. This case and the results of our tumour cyst fluid analysis raise several interesting considerations for the management of this unique situation in a rare disease.

Figure 1

CT scan of multicystic dedifferentiated retroperitoneal liposarcoma; (A) axial view and (B) coronal view.

Figure 2

Flow cytometry data from tumour cyst fluid. See text for full description; (A) live cells, (B) haematopoietic, immune cells, (C) T cells, including CD4 and CD8 subpopulations, and natural killer (NK) cells, (D) B cells, (E) antigen presenting cells and (F) Double negative immune cells, including myeloid-derived suppressor cells (MDSCs).

Figure 3

Serial CT scans after palliative debulking surgery. (A) Initial postoperative scan with residual disease in the pelvis; (B) change in tumour size and cyst wall thickness after single agent gemcitabine; (C) maximum regression of disease on single agent gemcitabine and (D) new, solid, enhancing lesion (green arrow).