Contributed by Hina Sheikh, MD and Fiona Craig MD
Published on line in August, 2004
A woman in her mid 40s who presented with left flank pain and symptoms of ureteral obstruction. She was initially treated with antibiotics for urosepsis and subsequently underwent radiologic imaging that showed a large retroperitoneal mass.
The patient underwent CT-guided biopsy at an outside hospital. She was referred to our hospital for definitive surgery. Intra-operatively, the mass was found to occupy the entire left retroperitoneum. It completely encased a large segment of the left ureter and was also adherent to the left kidney.
The specimen was composed of multi-nodular mass surrounded by scant amount of adipose tissue, 17 x 15 x 9 cm in greatest dimension. A segment of ureter with a stent in place was identified. Cut surface demonstrated a peripheral rim of fleshy tan-white tissue and central areas of dark-red hemorrhage and necrosis (Fig 1).
The mass demonstrated a diffuse proliferation of large spindled and ovoid cells, which were loosely cohesive with areas of vague storiforming (Fig 2, 3 and 4). There were moderate numbers of small lymphocytes interspersed with the larger cells and also around blood vessels (Fig 5). No residual lymph node tissue was identified. The large cells had eosinophilic cytoplasm, indistinct cytoplasmic borders and high nuclear/cytoplasmic ratios (Fig 6). The nuclei displayed both vesicular and granular chromatin, with occasional prominent nucleoli. Scattered giant cells with pleomorphic nuclei were identified (Fig 7). Extensive necrosis and cystic change was also present (Fig 8). The ureter at the margins of resection was uninvolved.
The large spindle cells were positive for CD21 (Fig 9), CD23 (Fig 10), LN3 (HLA-DR) and vimentin. S100 highlighted rare large atypical cells (Fig 11). Immunostain for CD1a was negative. Immunostains for lysozyme (Fig 12) and CD68 (Fig 13), highlighted small dendritic cells but were negative in the large tumor cells. CD20 and CD79a highlighted scattered small lymphocytes of B-cell lineage (Fig 14). CD3 highlighted small lymphocytes of T-cell lineage (Fig 15). No immunostaining for CD45, CD30, EMA, pancytokeratin, myosin heavy chain, desmin and melan-A was observed in the large atypical cells.