Diagnostic ultrasound ( PDFDrive )

CHAPTER 14 The Peritoneum 511
A
B
FIG. 14.14 Peritoneal Carcinomatosis. (A) Oblique sagittal ultrasound image of the midabdomen shows free luid in the peritoneal cavity and
a mildly hypoechoic nodular tumor implant involving the parietal peritoneum (arrow) immediately deep to the anterior abdominal wall. (B) Oblique
sagittal ultrasound image of the midabdomen shows free luid in the peritoneal cavity and a hypoechoic nodular tumor implant involving the visceral
peritoneum (arrow) on the serosal surface of a small bowel loop. See also Videos 14.5 and 14.6.
FIG. 14.15 Visceral Peritoneal Metastasis From Adenocarcinoma
of the Colon. Oblique sagittal image of the right upper quadrant shows
an echogenic nodule (arrow) on the surface of the liver (L), surrounded
by ascites. With respiration, the nodule moved in concert with the liver,
correctly suggesting its location on the visceral peritoneum.
of the peritoneum. 18 Ascites is common and may be the only
inding. he pouch of Douglas, greater omentum, Morison
pouch, and the right subphrenic space are common sites, 34
and therefore any sonographic evaluation of the peritoneum
for metastatic disease should include careful and detailed assessment
of these areas (Fig. 14.16). he parietal peritoneal line is
oten preserved on sonography with small seeds but is oten lost
as the lesion increases in size. Growth of a lesion is usually
inward, toward the peritoneal cavity, but growth outward with
invasion of the abdominal wall can occur (Fig. 14.17). If
L
psammomatous calciication occurs within a peritoneal nodule,
it appears echogenic with ultrasound, and if the calciication is
dense, it may demonstrate posterior acoustic shadowing
(Fig. 14.18).
Peritoneal carcinomatosis can be detected with ultrasound
in the absence of ascites (Figs. 14.19 and 14.20), but its presence
greatly enhances the detection of peritoneal lesions. Nodules as
small as 2 to 3 mm may be seen on the parietal and visceral
peritoneum with the transvaginal probe (Fig. 14.21). he detection
of omental involvement is also enhanced by ascites. Iniltration
of the omentum leads to an “omental cake,” 35 which may loat
freely in the ascitic luid (Fig. 14.22). Alternatively, the omentum
may be adherent to the parietal peritoneum in the near ield
(Fig. 14.23), or it may be deeper in the peritoneal cavity, adherent
to the visceral peritoneum and surrounding small bowel
loops (Fig. 14.24). hickening of the mesentery, mesenteric
nodules, and lymphadenopathy are other possible features of
carcinomatosis.
Ater the full extent of peritoneal involvement has been
documented with ultrasound, a careful search should be made
for the primary lesion within the abdomen and pelvis, if not
already identiied. his search should not be limited to the solid
organs, gallbladder, and bile ducts and should include the stomach
and bowel.
Primary Tumors of Peritoneum
Primary tumors of the peritoneum are rare and include primary
peritoneal serous papillary carcinoma, malignant mesothelioma,
and lymphoma. Primary peritoneal serous papillary
carcinoma is a multicentric peritoneal tumor that is morphologically
identical to ovarian serous papillary carcinoma of equivalent
grade but that can spare or minimally invade the ovaries. 36 Women
with primary peritoneal serous papillary carcinoma are more
likely to present with ascites than women with ovarian serous
papillary carcinoma and have a worse 3-year survival rate. 37