Dear Editor,

Dr. Aslam presented a rare case with peritoneal lymphomatosis and concluded that a histologic examination is crucial in the diagnosis, while cytology might sometimes mislead the workup.1 However, we present here another such case with raised CA 125 and demonstrate that cytology with a flow cytometry examination can help in the diagnosis.

This 44-year-old female suffered from autoimmune disorder and had been using steroids for several months. She was admitted to our ward due to progressive abdominal fullness, back soreness and shortness of breath. An abdominal echo revealed a pelvic mass with ascites. A computed tomography (CT) scan showed bilateral ovarian masses and multiple lymphadenopathies over the pelvic, abdominal and retroperitoneal areas. Biomarkers including CEA, SCC, AFP, CA 199, CA 153 were all within normal range except for a raised CA 125 level (125.27 U/ml, normal range 2.4~36.6 U/ml).

Ascitic fluid showing a turbid appearance was aspirated and sent for cytologic and microbiologic studies, however no micro-organisms grew from the culture. The cytologic study revealed massive lymphocytes with bizarre morphology. Flow cytometry was used to determine the characteristics of the cells, and showed positive for CD10, CD19, CD20, and negative for CD7.

Under the impression of suspected lymphoma with peritoneal lymphomatosis, CT guided biopsy of the lymph node was done. The resulting histology examination revealed a diffuse large B cell lymphoma which was positive for LCA, CD20 and negative for cytokeratin and CD7 (fig 1). She received systemic chemotherapy with R-CEOP regimen, but unfortunately died of sepsis.

Peritoneal lymphomatosis is a rare manifestation of malignant lymphoma. Although there are some criteria that tell the difference of peritoneal lymphomatosis from carcinomatosis, most of the cases are indistinguishable from the clinical presentations and image studies.2,3 Even the tumor markers, such as a raised CA 125 as in this case, cannot rule out the diagnosis of peritoneal lymphomatosis completely.4 These factors stress the importance of putting lymphoma into the list of diagnoses in such patients. We also highlight the important role of cytology examinations with flow cytometry, which might also help the physician in the diagnosis of peritoneal lymphomatosis and avoid unnecessary studies and treatment.

Hui-Hua Hsiao,^{1, 2} Yi-Chang Liu,^{1, 2} Jui-Feng Hsu,¹ Sheng-Fung Lin^1,2

1 Faculty of Medicine, College of Medicine, Kaohsiung Medical University; and

2 Division of Hematology-Oncology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.

Correspondence to: Dr SF Lin, Department of Internal Medicine, Kaohsiung Medical University Hospital, 100, Tzu-You 1st Road, Kaohsiung 801, Taiwan. E-mail: shlin@cc.kmu.edu.tw

Competing interests: none

REFERENCES

1. Aslam MB. Peritoneal lymphomatosis, a morphological look alike to peritoneal carcinomatosis: a autopsy report. J Clin Pathol 2009;62:480.

2. Kim Y, Cho O, Song S, et al. Peritoneal lymphomatosis: CT findings. Abdom Imaging 1998;23:87-90.

3. Karaosmanoglu D, Karcaaltincaba M, Oguz B, et al. CT findings of lymphoma with peritoneal, omental and mesenteric involvement: Peritoneal lymphomatosis. Eur J Radiol 2008; in press

4. Horger M, Muller-Schimpfle M, Yirkin I, et al. Extensive peritoneal and omental lymphomatosis with raised CA 125 mimicking carcinomatosis: CT and intraoperative findings. Br J Radiol 2004;77:71-3.

FIGURE LEGEND

Diffuse infiltration of medium-sized, monotonous round cells with hyperchromatic nuclei and scant cytoplasm (H&E stain, x400). Upper right: Positive CD20 reaction to the lymphoma cells and no reaction to endothelial cells.