Black ascites.

A 71-year-old man with abdominal distension for 2 months as a result of ascites from a cytologically diagnosed adenocarcinoma was admitted to our hospital for further evaluation. His ascites was drained by puncture to enable preparation of ascites cell blocks and perform cell-free concentrated ascites reinfusion therapy (CART)[1] This yielded 8.4 L of black ascites (Fig. 1) containing 1.6 g/dL hemoglobin (left tube, Fig. 2). This was reduced to 0.01 g/dL after filtering to remove cellular components and then concentrated (right tube, Fig. 2). Reinfusion was abandoned because of the possible risk of bacterial peritonitis; however, culture for bacteria in the ascitic fluid was negative. The blackness of the ascites was considered attributable to denatured hemoglobin, thus indicating bleeding from cancerous peritonitis. The ascites was drained by puncture again 11 days later, yielding 5.0 L of pale yellow ascites containing 0.03 g/dL hemoglobin, after which CART was performed without complications. The final diagnosis was cancer from an unknown primary. He died in a palliative care hospital. No autopsy was performed.

Fig. 1

Drainage of ascites by puncture yielded about 8.4 L of black ascites

Fig. 2

The black ascites contained 1.6 g/dL hemoglobin (left tube) before concentration

This reduced to 0.01 g/dL after filtering to remove cellular components and then concentrating it (right tube).

Black ascites is rare.[2] The differential diagnosis of black ascites includes melanoma, ovarian cancer, bowel perforation with leakage of fecal matter, fungal peritonitis, pancreatic ascites, and leakage of tattoo ink.[3-5] To the best of our knowledge, this is the first report of black ascites caused by denatured hemoglobin from bleeding as a result of cancerous peritonitis. When black ascites is detected, such bleeding should be included in the differential diagnosis.

ACKNOWLEDGEMENTS

We thank Dr Trish Reynolds, MBBS, FRACP, from Edanz (https://jp.edanz.com/ac) for editing a draft of this manuscript.

CONFLICTS OF INTEREST

YS reports personal fees from ONO Pharmaceutical Co., Ltd, Bristol-Myers Squibb Company, MSD KK, TAIHO Pharmaceutical Co., Ltd, and Eisai outside the submitted work. NH report no competing interests to disclose. ST reports grants and personal fees from Bristol-Myers Squibb KK, grants and personal fees from ONO Pharmaceutical Co., Ltd, grants and personal fees from MSD, grants and personal fees from AstraZeneca, grants and personal fees from Chugai, and grants and personal fees from BAYER, outside the submitted work.