Table of Contents
Definition / general | Epidemiology | Etiology | Clinical features | Prognostic factors | Treatment | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Positive stains | Differential diagnosisCite this page: Mucinous Carcinoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/uterusmucinous.html. Accessed July 16th, 2017.
Definition / general
- Adenocarcinoma with abundant intracellular mucin
- May have enteric features
- May have a microglandular pattern with eosinophilic, mucinous intraluminal secretion and acute inflammation, simulating microglandular hyperplasia
- Mucin should be a predominant component of the tumor since scattered mucin is present in ordinary endometrial adenocarcinoma
- Mucinous carcinomas may be primed by exogenous estrogen therapy
Epidemiology
- Rare tumor (< 1% of endometrial carcinomas, up to 9% of stage I endometrial carcinomas) that affects patients 47 - 89 years
Etiology
- Unknown
Clinical features
- Most patients are menopausal and present with vaginal bleeding, usually not abdominal pain
- Both nulliparous and multiparous women
Prognostic factors
- Usually FIGO grade 1 and nuclear grade 1 with favorable prognosis (Int J Gynecol Pathol 1987;6:347)
Treatment
- TAH / BSO then possible radiation (for advanced disease) for disease limited to the uterus (NCCN Guidelines Version 1.2014); consideration of preoperative radiation for tumors grossly involving the cervix before doing surgery (this is uncommon)
Gross description
- Similar to other low grade adenocarcinomas at gross examination; may not be grossly apparent
- Visible tumors vary from sessile polyps to nodules or irregular, thickened plaques that may be localized or diffuse
Microscopic (histologic) description
- Intracellular (not intraluminal) mucin is required for diagnosis; best demonstrated with mucicarmine or other mucin stain; however, mucin is easily visible with H&E staining
- Malignant features include architectural complexity of proliferation, epithelial stratification, loss of epithelial polarity, nuclear atypicality (Am J Surg Pathol 1983;7:715)
- Microglandular pattern and intestinal differentiation with goblet cells are different variants
- Low grade tumors also occur (Am J Surg Pathol 2011;35:537)
Microscopic (histologic) images
Cytology description
- Tumor cells arranged in papillary configuration and tumor cell clusters with bubbles in cytoplasm
Differential diagnosis
- Primary, mucinous carcinoma of endocervix: CEA+, negative for vimentin and ER
- Endocervical adenocarcinoma: may need differential biopsy and fractional curettage, not associated with endometrial hyperplasia or metaplasia, no foam cells
- Mucinous metaplasia: no atypia
- Microglandular hyperplasia: benign, no atypia




