A total of 167 specimens from 133 patients were identified by our search. The patients ranged from 29 to 85 years of age (mean 56 years).
Alcohol abuse was the most common cause of cirrhosis in this patient population, accounting for 44 cases alone and 22 more in combination with hepatitis viruses. The hepatitis C virus alone accounted for 30 cases and Hepatitis B virus alone for six cases. Other causes included: non-alcoholic steatohepatitis (seven cases), autoimmune hepatitis (three cases), sarcoidosis (one case), cardiogenic cirrhosis (one case), and alpha-1-antitrypsin deficiency (one case). Cirrhosis was cryptogenic in the remaining 18 cases.
Among these cirrhotic patients, 17 had a history of HCC, either confirmed by biopsy or strongly suspected on the basis of radiological studies. Two others had a history of previously resected HCC. Only one patient had a history of metastatic HCC.
Additional confounding factors were present in some cases: The status of fifteen patients was post liver transplant with recurrent liver failure; seven were known to be positive for Human Immunodeficiency Virus, and eight had a history of non hepatic malignancy.
Of the 167 specimens, 162 were negative. Atypical lymphocytes were present in two of the patients. One of these patients had a known history of diffuse large B-cell lymphoma. Peritoneal involvement by a monoclonal B-cell process was confirmed in a concurrent ascites fluid specimen sent to the flow cytometry laboratory. The other patient had a history of severe combined immunodeficiency syndrome. Flow cytometry revealed no clonal population; however, a previous paracentesis sent to hematopathology, and a subsequent bone marrow specimen, were suspected to have T-cell lymphoproliferative disorder.
Three cases had atypical epithelioid cells identified. In all the three cases, the cells of interest were large, with a high nucleus-to-cytoplasm ratio and nuclear changes including moderate anisonucleosis and prominent nucleoli. A few mitoses were observed. The cells of interest were also predominantly dyscohesive in every case, although cohesive clusters were present in two cases. No distinct second cell population was present in any of the three cases. Nuclear contour irregularities and chromatin clumping ranged from minimal to marked, while multinucleation ranged from rare to frequent in the different specimens. Upon review, the atypical cells from all the three cases are believed to be reactive mesothelial cells. All three patients died within a few days of the collection of the ascites fluid specimens, with atypical epithelioid cells present. Autopsies were not performed on any of these cases.
Case #1 was a 58-year-old female with end-stage cirrhosis due to Hepatitis B infection. Abdominal computed tomography scans demonstrated a small, nodular liver with a large exophytic mass, suspicious for HCC. She had had a previous negative ascites fluid cytology during the study period. The atypical epithelioid cells were present only on the cell block . The atypical epithelioid cells were negative by mucicarmine special stain and positive for calretinin  (Cell Marque, Rocklin, CA; dilution 1: 80), WT-1 (Dako, Carpineria, CA; dilution 1: 50), and cytokeratin 5/6 (Dako, Carpinteria, CA; dilution 1: 50) by immunocytochemistry, confirming a mesothelial origin. Acute inflammation was also present. The patient died from catheter-associated sepsis, soon after the specimen was collected.
Figure 1 Clustered atypical epithelioid cells from case #1. Most of the cells seen in the cell block were dyscohesive, a few clusters with smooth community borders were seen, such as those pictured here, raising suspicion of a carcinoma. Note the mild atypia with (more ...)
Figure 2 Calretinin immunocytochemical stain from case #1. Clusters and individual cells in the background both stained strongly for calretinin in the cytoplasm and nucleus, confirming the mesothelial origin of the cells of interest in the cell block. (Peroxidase (more ...)
Case #2 was a 65-year-old male, with a history of alcoholic cirrhosis complicated by hepatorenal syndrome requiring dialysis and a remote history of surgically resected renal cell carcinoma. A computed tomography scan performed at the time of the paracentesis demonstrated widespread metastatic disease, presumed to be renal cell carcinoma recurrence. As with case 1, this patient had had a previous negative ascites fluid cytology. Atypical epithelioid cells were seen in Papanicolaou stained smears  and in a cell block. He had the following immunocytochemical findings: cells of interest in the cell block stained positive for calretinin , WT-1, and cytokeratin 5/6 and negative for B72.3 (Covance/Signet, Dedham, MA; dilution 1: 60) and CD10 (Leica/Novocastra, Bannockburn, IL; dilution 1: 50) as well as a special stain for mucicarmine. The patient died shortly after paracentesis, with peritonitis as a probable contributing factor.
Figure 3 Atypical epithelioid cells in a Papanicolaou stained smear from case #2. Epithelioid cells were noted on smears and in the cell block. This Papanicolaou stain demonstrates typical examples with nuclear enlargement, mild nuclear contour irregularities, (more ...)
Calretinin immunocytochemical stain from case #2. Diffusely and strongly stained all epithelioid cells in the cell block, confirming mesothelial derivation. (Peroxidase stain, 600× magnification)
Case #3 was a 76-year-old female with a history of autoimmune hepatitis causing cirrhosis status-post liver transplant. Atypical epithelioid cells were seen in Papanicolaou stained smears . The patient died from sepsis soon after the specimen was acquired, possibly arising from peritonitis. No additional studies were performed on the cytology specimen. Computed tomography scans just before the death of the patient did not show any conclusive evidence of tumor anywhere in the pelvis, abdomen, or thorax. A loculated perihepatic fluid collection was present, associated with peritoneal thickening, for which an infectious etiology was favored.
Figure 5 Atypical epithelioid cells in a Papanicolaou stained smear from case #3. Pleomorphic cell population was present on smears. Nuclei showed anisonucleosis, focal deep grooves, prominent nucleoli, and chromatin clumping. Cytoplasm was scant with focal vacuolization. (more ...)