CASE 15021 Published on 12.11.2017

Recurrent mucinous breast cancer

Section

Breast imaging

Case Type

Clinical Cases

Authors

Benjamin Leenknegt; Ivo Van Den Berghe; Charlotte Biebaы; Katrien Gieraerts; Luc Steyaert

Department of Radiology,
AZ Sint-Jan Brugge;
Ruddershove 10
8000 Brugge, Belgium.
Email:benjamin_leenknegt@hotmail.com
Patient

87 years, female

Categories
Area of Interest Breast, Bones ; Imaging Technique Mammography, Ultrasound
Clinical History
An 87-year-old woman was referred to the radiology department for nipple retraction of the right breast. She had a history of mucinous breast cancer of the same breast 24 years earlier, with free margin resection of the tumour, axillar lymphadenectomy and adjuvant radiotherapy. Pathologic stage was pT1 pN0 cM0.
Imaging Findings
Mammography (Fig. 1) shows a coarse macro-calcification in the lateral segment of the right breast, and more posteriorly two smaller calcifications. Anterior to the largest calcification is a soft tissue density. There is a volume loss of the breast and nipple retraction.
Ultrasound (Fig. 2) confirms the presence of a soft tissue mass adjacent to the calcification. No pathologically enlarged lymph nodes were visualised.
Comparison with previous mammography (Fig. 3) taken over a period of 12 years shows progressive growth of the largest calcification. There is a slow, progressive volume loss of the breast with progressive approximation of the two smaller, posteriorly located calcifications. A soft tissue density appears in 2014, partially obscured by the fibro-glandular tissue. In 2017, the soft tissue density has grown compared to 2014.
Discussion
Mucinous breast cancer is a mucin-producing subtype of invasive ductal adenocarcinoma [1]. It accounts for 1-4% of all breast carcinomas. Prognosis is generally good [2]. On imaging studies mucinous breast cancer often has benign characteristics.
On mammography, the mucinous breast carcinoma typically appears as a round to oval, iso- to hyperdense lesion. Margins often are (micro)lobulated. Calcifications can occur, but are non-specific [3-4]. On ultrasound, mucinous breast carcinoma most often appears as a well-defined, hypo- to iso-echoic lesion. Vascularisation often is present. Lymph node involvement is rare [3-8].
On pathological examination, a mucinous breast cancer is heterogeneous, consisting of cystic pools of mucin and more solid islands of tumour cells. The tumour cells most frequently show characteristics of a moderately differentiated adenocarcinoma. Extinguished tumour cells can sclerotise and form slow growing calcifications [5, 7-8].
In a patient with a history of treated mucinous breast cancer, discrete changes over long periods of time on mammography and ultrasound raise suspicion of a recurrent mucinous breast cancer. Calcifications frequently occur in the post-therapy breast and are generally considered benign post-therapeutic calcifications, even when slowly changing in time [9-11]. In a patient who had a mucinous breast, however, because extinguished tumour cells can sclerotise and calcify [5, 7-8], newly appearing or slowly growing calcifications should raise suspicion of a recurrent cancer. Ultrasound is a good imaging modality to detect small, vascularised soft tissue masses [7]. Whenever in doubt, an ultrasound-guided breast biopsy should be performed.

Due to its slow growth and benign characteristics, the follow up after treatment of a mucinous breast carcinoma forms a diagnostic challenge. Slow evolution in time is the key to diagnosis and comparison to former imaging is imperative. Any suspicion of growth indicates an ultrasound-guided breast biopsy. However, benign in terms of growth and tumour spread, the pure mucinous breast cancer is a malignant breast tumour with need of invasive treatment.
Differential Diagnosis List
Pathological examination confirmed the diagnosis of recurrent mucinous breast cancer.
Postoperative liponecrosis calcifications
Calcified fibroadenoma
Ductal adenocarcinoma
Final Diagnosis
Pathological examination confirmed the diagnosis of recurrent mucinous breast cancer.
Case information
URL: https://eurorad.org/case/15021
DOI: 10.1594/EURORAD/CASE.15021
ISSN: 1563-4086
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