Mucinous cystadenoma is the second most common benign epithelial tumor of the ovary. It is recognized by its characteristic stained-glass appearance consisting of multilocular locules with different echogenicity and density. Locules filled with viscous mucinous fluid exhibit different signal/density characteristics due to varying protein and mucin concentration in each locule. It typically reaches large sizes (often >10 cm, can be >30 cm in giant forms) and is unilateral (95%). Rarely, it may be associated with pseudomyxoma peritonei. Surgical excision is the standard treatment; intact removal is important because rupture may spread mucinous material into the peritoneal cavity.
Age Range
20-50
Peak Age
40
Gender
Female predominant
Prevalence
Uncommon
Mucinous cystadenoma consists of mucin-secreting columnar epithelium. The epithelium may be gastrointestinal type (intestinal) or endocervical type (müllerian) — intestinal type is more common. Each locule produces mucin at different concentrations; mucin is a high molecular weight glycoprotein that increases viscosity. These different mucin concentrations create different echogenicity on US (anechoic → low → medium echo), different density on CT (water density to soft tissue density, 0-30 HU), and different T1 and T2 signal intensity on MRI — this heterogeneous multilocular appearance is known as the stained-glass pattern. The tumor typically reaches large sizes because mucin accumulation is progressive and continuous. Septa represent fibrovascular stroma and can take up contrast. Wall and septa are smooth — irregularity or mural nodule presence suggests borderline or malignant transformation.
In a multilocular cystic lesion, adjacent locules show different echogenicity — each piece appears different like a stained-glass window. Results from differences in mucin concentration. Can also be confirmed on MRI with different signal intensity on T1. This pattern strongly suggests mucinous origin and is a key finding for differentiation from serous type (homogeneously anechoic).
Multilocular cystic lesion with different echogenicity in each locule — contents varying from anechoic to low/medium echogenicity. Stained-glass appearance: marked echogenicity difference between adjacent locules. Septa are generally thin-to-moderate thickness, smooth. Lesion is usually large (>10 cm).
Report Sentence
A ___ x ___ mm multilocular cystic lesion is seen in the right/left ovary with different echogenicity between locules creating a stained-glass appearance; consistent with mucinous cystadenoma.
Minimal vascularity may be seen in septa on Doppler — as thin vascular lines. NO increased vascularity in mural nodule or papillary projection areas. No ring-of-fire pattern. Thin, regular vascular flow along septa is consistent with benign fibrovascular stroma.
Report Sentence
Minimal vascularity is seen in septa on Doppler examination; no increased vascularity in mural nodule or papillary projection area is detected.
Multilocular cystic lesion with inter-locular density difference (0-30 HU). Locules with low mucin concentration are near water density (0-10 HU), locules with high mucin concentration approach soft tissue density (15-30 HU). Septa are thin-to-moderate thickness, smooth, with mild enhancement. No solid component or mural nodule.
Report Sentence
A ___ x ___ mm multilocular cystic lesion is seen in the right/left adnexal region with locules showing varying densities between ___ and ___ HU; consistent with mucinous cystadenoma.
Marked signal difference between locules on T1W. Locules with low mucin concentration are T1 hypointense (free water), locules with high mucin concentration are T1 hyperintense (proteinaceous fluid effect). This T1 signal variation is an important finding distinguishing mucinous cystadenoma from serous cystadenoma (homogeneously hypointense).
Report Sentence
Marked signal difference between locules is seen in the multilocular cystic lesion on T1W, with some locules showing hyperintense and others hypointense signal; consistent with mucinous content.
All locules are hyperintense on T2W but with intensity differences. Locules with low mucin concentration are markedly hyperintense (free water), locules with high mucin concentration show less hyperintense or intermediate signal. Septa are seen as hypointense lines on T2.
Report Sentence
Locules in the multilocular cystic lesion show hyperintense signal of varying intensity on T2W; septa are delineated as hypointense lines.
No diffusion restriction on DWI. Locules with high mucin concentration may show T2 shine-through effect — hyperintense on DWI but also hyperintense on ADC. True diffusion restriction (DWI hyperintense + ADC hypointense) is absent — this excludes abscess or solid tumor.
Report Sentence
No true diffusion restriction is detected on DWI; T2 shine-through effect is seen in some locules.
Large (>10 cm) multilocular cystic mass in pelvic/abdominal location on non-contrast CT. Inter-locular density difference may be visible even on non-contrast series. Calcification may rarely be found in wall or septa. Absence of peritoneal fluid (ascites) favors benign character.
Report Sentence
A large ___ x ___ x ___ mm multilocular cystic mass is seen in the pelvic/abdominal region; mucinous cystadenoma of ovarian origin should be primarily considered.
Criteria
Gastrointestinal type goblet cell epithelium. Most common subtype (85%). CK20 positive, CK7 positive.
Distinct Features
May be associated with appendiceal mucinous tumor — pseudomyxoma peritonei may develop. If bilateral, appendiceal primary should be investigated. Tendency to reach large size is more pronounced.
Criteria
Endocervical type mucin-secreting epithelium. Less common (15%). CK7 positive, CK20 negative.
Distinct Features
Tendency toward smaller sizes. No association with appendix expected. Coexistence with endometriosis may be seen.
Criteria
>20 cm or >4 kg size/weight. Causes abdominal distension. Multilocular cystic mass filling the entire abdomen and pelvis on CT/MRI.
Distinct Features
Mass effect is prominent — bowel, bladder, ureter compression. Torsion risk is high. Rupture risk is present. Surgical excision is unavoidable — intact removal is critical.
Distinguishing Feature
Serous cystadenoma is unilocular/oligolocular, homogeneously anechoic, thin septa, and smaller. NO stained-glass pattern. Homogeneously T1 hypointense on MRI (mucinous type: inter-locular T1 signal difference).
Distinguishing Feature
Mucinous borderline tumor shows mural nodules, thick/irregular septa (>3 mm), papillary projections, and enhancing solid component. In benign mucinous cystadenoma, septa are thin, smooth; NO mural nodules or papillary projections.
Distinguishing Feature
Mucinous carcinoma shows prominent solid component, thick irregular wall, intense enhancement, ascites, peritoneal implants, and usually large size. Diffusion restriction is present in solid component. Benign mucinous cystadenoma has no solid component, ascites, or peritoneal implants.
Distinguishing Feature
Krukenberg metastasis (GI origin) appears as bilateral, solid-cystic mixed lesion. History of known GI malignancy is important. Mucinous cystadenoma is 95% unilateral and entirely cystic — no solid component.
Urgency
routineManagement
surgicalBiopsy
Not NeededFollow-up
6-monthMucinous cystadenoma is a benign lesion but surgical excision is generally recommended due to large size and risk of surgical complications. For small (<5 cm), asymptomatic lesions, 6-month US follow-up may be applied. Intact removal during surgery is critical — rupture may spread mucinous material into the peritoneal cavity risking pseudomyxoma peritonei. The appendix should be evaluated in some intestinal type cases. When bilateral mucinous tumor is detected, appendiceal or colorectal primary should be investigated.
Mucinous cystadenomas usually present with abdominal distension and pressure symptoms. Surgical excision is curative. Differentiating benign mucinous cystadenoma from borderline and malignant mucinous tumors is important (solid component, thick septa = poor prognostic markers).