Diagnostic Ultrasound - Abdomen and Pelvis

Mucinous Ovarian Cystadenoma/Carcinoma
Diagnoses: Female Pelvis
TERMINOLOGY
• Mucinous epithelial neoplasm, which can be benign
(mucinous cystadenoma), borderline (low malignant
potential), or malignant (mucinous cystadenocarcinoma)
IMAGING
• Multilocular cystic mass with low-level echoes
○ Papillary projections much less common than in serous
tumors
○ Solid components increase suspicion for malignancy
• Variable in size, but often large; may fill entire pelvis and
extend into upper abdomen
• Pseudomyxoma peritonei is potential form of peritoneal
spread
○ Amorphous, mucoid material insinuating itself around
mesentery, bowel, and solid organs
TOP DIFFERENTIAL DIAGNOSES
• Endometrioma
KEY FACTS
• Serous cystadenoma/carcinoma
PATHOLOGY
• Method of spread
○ Intraperitoneal dissemination most common
(pseudomyxoma peritonei)
○ Direct extension to surrounding organs
○ Lymphatic spread to paraaortic and pelvic nodes
CLINICAL ISSUES
• Massive tumors can cause weight gain and distended
abdomen
• Mucinous tumors 2nd most common epithelial neoplasm
• Gelatinous, insinuating nature of pseudomyxoma peritonei
makes complete resection difficult
DIAGNOSTIC CHECKLIST
• Mucinous tumors are less commonly malignant than serous
tumors
(Left) Septations within a
mucinous tumor are typically
thin, creating multiple
intervening locules, as seen in
this transverse
transabdominal ultrasound.
(Right) Axial T2WI MR shows
varying signal within the
locules of the mass, due to
differing concentrations of
mucin st. Loculi with a high
concentration of mucin will be
higher signal on T1WI and
lower signal on T2WI.
(Left) Sagittal grayscale US of
the right adnexa shows a large
multiloculated mucinous
cystadenoma. Multiple
septations separate locules
with varying degrees of
internal low level echoes,
creating a characteristic
stained glass appearance.
(Right) Closer inspection with
transvaginal imaging in a
different patient shows lowlevel
echoes within the largest
locule (calipers), consistent
with mucin.
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