Contributed by Kudakwashe Chikwava, MB, ChB. and Steven Swerdlow, MD.
Published on line in February 2004
We present a case of a female in her 60s with what turned out to be an uncommon condition. The patient was admitted at an outside hospital with an abdominal pelvic mass. She underwent a bilateral salpingo-oophorectomy with biopsy of the omentum. A frozen section diagnosis of a "'small blue cell tumor', differential includes carcinoma, stromal tumor and lymphoma" was rendered. There were no known preexisting conditions.
Flow cytometric immunophenotypic studies performed on the pelvic mass at an outside hospital were reported as follows: "The gated region contains 3% of the total number of cells. The cells in this region are a mixture of heterogeneous T-lymphocytes and polyclonal B-lymphocytes. Another region contains 50% of the total numbers of cells and consists mainly of neutrophils. No increase in blasts is detected. No evidence of a lymphoproliferative disorder or of acute leukemia is detected. No specific diagnostic changes are noted".
Flow cytometric studies of bone marrow aspirate did not suggest the diagnosis of a lymphoma or leukemia.
The histologic sections available for review showed fallopian tube and adjacent tissues with an extensive infiltrate that had areas with a starry sky appearance (Figure 1). The infiltrate was composed mostly of immature appearing cells with dispersed chromatin and often one to two nucleoli (Figure 2). Some areas showed occasional mature appearing eosinophils, and there were also some lymphocytes lying singly and in occasional aggregates. Some of the more normal appearing areas in the fallopian tube with chronic inflammation had apparent lymphovascular invasion (Figure 3).
Paraffin section immunohistochemical stains revealed the infiltrate to stain positively for the leukocyte common antigen/CD45, CD43, Myeloperoxidase (MPO), c-kit/CD117, neutrophil elastase and vimentin (Figures 4, 5, 6, 7, 8 and 9). CD20, CD3 and CD34 immunostains were negative (Figures 11 and 12).
The infiltrate was also negative for cytokeratin (pancytokeratin and low molecular weight keratin stains), chromogranin, synaptophysin, S100/S100a, TdT, CD56, CD68/PGM1, lysozyme, tryptase, and CD30.