RT Book, Section
A1 McQuaid, Kenneth R.
A2 Papadakis, Maxine A.
A2 McPhee, Stephen J.
A2 Rabow, Michael W.
A2 McQuaid, Kenneth R.
SR Print(0)
ID 1184169561
T1 Malignant Ascites
T2 Current Medical Diagnosis & Treatment 2022
YR 2022
FD 2022
PB McGraw-Hill Education
PP New York, NY
SN 9781264269389
LK accessmedicine.mhmedical.com/content.aspx?aid=1184169561
RD 2024/04/18
AB Two-thirds  of  cases  of  malignant  ascites  are  caused  by  peritoneal  carcinomatosis.  The  most  common  tumors  causing  carcinomatosis  are  primary  adenocarcinomas  of  the  ovary,  uterus,  pancreas,  stomach,  colon,  lung,  or  breast.  The  remaining  one-third  is  due  to  lymphatic  obstruction  or  portal  hypertension  due  to  hepatocellular  carcinoma  or  diffuse  hepatic  metastases.  Patients  present  with  nonspecific  abdominal  discomfort  and  weight  loss  associated  with  increased  abdominal  girth.  Nausea  or  vomiting  may  be  caused  by  partial  or  complete  intestinal  obstruction.  Abdominal  CT  may  be  useful  to  demonstrate  the  primary  malignancy  or  hepatic  metastases  but  seldom  confirms  the  diagnosis  of  peritoneal  carcinomatosis.  In  patients  with  carcinomatosis,  paracentesis  demonstrates  a  low  serum  ascites-albumin  gradient  (less  than  1.1  mg/dL),  an  increased  total  protein  (greater  than  2.5  g/dL),  and  an  elevated  white  cell  count  (often  both  neutrophils  and  mononuclear  cells)  but  with  a  lymphocyte  predominance.  Cytology  is  positive  in  over  95%,  but  laparoscopy  may  be  required  in  patients  with  negative  cytology  to  confirm  the  diagnosis  and  to  exclude  tuberculous  peritonitis,  with  which  it  may  be  confused.  Malignant  ascites  attributable  to  portal  hypertension  usually  is  associated  with  an  increased  serum  ascites-albumin  gradient  (greater  than  1.1  g/dL),  a  variable  total  protein,  and  negative  ascitic  cytology.  Ascites  caused  by  peritoneal  carcinomatosis  does  not  respond  to  diuretics.