Benign mucocele‐like lesion of the breast: how to differentiate from mucinous carcinoma before surgery

Abstract

The aim of the study was to improve the pre-operative diagnosis of mammary mucinous lesions. All mucinous lesions detected by fine needle aspiration (FNA) and confirmed by histological examination were reviewed by cytological findings, mammographic appearances and sonographic findings. Twenty aspirates had corresponding pathology, including 12 mucinous carcinomas, two mucocele-like lesions (MLL) with atypical ductal hyperplasia, three MLL with ductal hyperplasia and three simple MLL. Simple MLL and mucocele-like with ductal hyperplasia showed scant cellularity, no or rare intact single tumour cells, monolayered arrangement and absence of nuclear atypia. In contrast, most mucinous carcinomas showed higher cellularity, more single tumour cells, three-dimensional clusters, and mild to marked nuclear atypia. However, MLL with atypical ductal hyperplasia showed cytological features overlapping with mucinous carcinoma. MLL had a non-specific mammographic appearance and showed a cystic lesion on sonography. Mucinous carcinoma appeared as a solid mass on sonography and as a distinct nodule on mammography. Based on the combination of FNA cytology and image findings, benign MLL can be correctly distinguished from mucinous carcinoma before surgery.

Indeterminate calcification and clustered cystic lesions are strongly predictive of the presence of mucocele-like tumor of the breast: a report of six cases

“…In such cases, the next step is to differentiate MLT from mucinous carcinoma. Though discrimination between MLTs and carcinomas is generally difficult by FNAC, experienced cytologists can distinguish between them by noting cellularity, the shape of cell clusters, cellular or nuclear atypia, and mucinous materials in FNAC samples [9][10][11][12][13]. Aspirates from MLTs, obtained by FNAC, contain thick, jelly-like, mucinous material.…”

Performance Characteristics of Mucinous (Colloid) Carcinoma of the Breast in Fine-Needle Aspirates: Observations From the College of American Pathologists Interlaboratory Comparison Program in Nongynecologic Cytopathology

“…[1][2][3][4][5]7 The diagnostic features of MC by breast FNA are well established in the literature. [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] Mucinous carcinoma often shows grossly visible jellylike mucin when obtained by FNA, which correlates to the abundant mucin in the background of the smears. The mucinous material is much more readily seen on modified Giemsa-stained slides owing to the metachromatic staining of the mucin.…”

“…The smears contain a mixed population of cohesive epithelial and myoepithelial cells, apocrine cells, macrophages, and detached myxoid stromal fragments. [9][10][11][12][13][14][17][18][19][20][21] The myxoid change is often present focally in these benign lesions and not diffusely as seen in MC. The epithelial component of MC has a uniform appearance without myoepithelial cells.…”

“…These include mucinous cysts, benign mucocele-like lesions, mucinous spherulosis, mucocele-like lesion with atypia (atypical ductal hyperplasia), mucocele-like lesion with ductal carcinoma in situ, myxoid changes in fibroadenoma, ductal carcinoma, and lobular carcinomas with mucinous features. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] Fine-needle aspiration biopsy has been routinely used for the diagnosis and management of palpable breast lesions. In this setting, false-positive and false-negative rates vary depending on the expertise of the individual performing the biopsy and interpreting the results, as well as the morphologic subtype of breast cancer.…”

Diagnostic Dilemma in Cytologic Features of Micropapillary Carcinoma of the Breast

“…14 In the smears of traditional mucinous carcinoma, cohesive small tumor clusters or ribbons with mild to moderate nuclear atypia were seen in the background of abundant mucin. 12,15,16 Sometimes, monolayered tumor cell sheets can have an appearance like honeycomb. 15 Occasionally, tumor cells containing intracytoplasmic vacuoles, nuclear hobnailing and psammoma bodies may also be seen.…”