Imaging findings in mucin-containing carcinomas of the breast: correlation with pathologic features

An Effective Ultrasound Features-Based Diagnostic Model via Principal Component Analysis Facilitated Differentiating Subtypes of Mucinous Breast Cancer From Fibroadenomas

BACKGROUND

Mucinous breast carcinoma (MBC) is often misdiagnosed as fibroadenoma (FA),which can lead to inappropriate or delayed treatments. This study aimed to establish an efficient ultrasound (US)-based diagnostic model to distinguish MBC subtypes from FAs.

METHODS

Between January 2017 and February 2024, 240 lesions were enrolled, comprising 65 cases of pure mucinous breast carcinoma (PMBC), 47 cases of mixed mucinous breast carcinoma (MMBC), and 128 cases of FAs. Ten US feature variables underwent principal component analysis (PCA). Models were constructed based on components explaining over 75% of the total variation, with varimax rotation applied for interpretability. Comprehensive models were developed to distinguish PMBCs and MMBCs from FAs.

RESULTS

Six principal components were selected, achieving a cumulative contribution rate of 77.46% for PMBCs vs. FAs and 78.62% for MMBCs vs. FAs. The principal component of cystic-solid composition and posterior acoustic enhancement demonstrated the highest diagnostic value for distinguishing PMBCs from FAs (AUC: 0.86, ACC: 80.31%). Features including vascularization, irregular shape, ill-defined border, and larger size exhibited the highest diagnostic value for distinguishing MMBCs from FAs (AUC: 0.90, ACC: 87.43%). The comprehensive models showed excellent clinical value in distinguishing PMBCs (AUC = 0.86, SEN = 86.15%, SPE = 73.44%, ACC = 77.72%) and MMBCs (AUC = 0.92, SEN = 80.85%, SPE = 95.31%, ACC = 91.43%) from FAs.

CONCLUSION

This diagnostic model holds promise for effectively distinguishing PMBCs and MMBCs from FAs, assisting radiologists in mitigating diagnostic biases and enhancing diagnostic efficiency.

Spectrum of Mucin-containing Lesions of the Breast: Multimodality Imaging Review with Pathologic Correlation

Mucin-containing lesions of the breast encompass a wide range of benign and malignant processes. The spectrum of histologic findings includes incidental mucus-filled benign cysts or ducts, mucocele-like lesions (MLLs), mucin-producing ductal carcinoma in situ, and invasive mucinous carcinoma. MLL is characterized by the presence of mucin-containing cysts that are typically associated with extravasated stromal mucin. MLL is often benign but can be associated with epithelial atypia or malignancy. Mucinous carcinoma represents the malignant end of the spectrum of mucinous lesions of the breast. Evidence-based literature supports a conservative approach for benign MLLs without associated atypia or malignancy, reserving excision for those lesions exhibiting such pathologic features. The most common imaging finding for MLL is microcalcifications at mammography. No specific imaging feature is predictive of malignant outcome at surgical excision. Invasive mucinous carcinoma is a heterogeneous breast tumor subtype, as defined according to the World Health Organization criteria. Mucinous carcinomas are categorized into pure (>90% mucinous component) or mixed (10%-90% mucinous component) subtypes. Pure mucinous carcinomas are generally associated with excellent prognosis and survival, with a few exceptions. Mixed mucinous carcinomas do not have the same favorable prognosis and instead behave similarly to invasive breast carcinomas of no special type. Characteristic diagnostic imaging features can be identified for mucinous carcinoma based on its mucinous and nonmucinous contents. ©RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

Synchronous bilateral breast cancer with different histology

Synchronous bilateral breast cancer is a rare clinical entity. And due to both an improved prognosis and growing life expectancy on early detection, we have brought interest in case of patient with synchronous breast cancer. This study reports a case of synchronous bilateral breast cancer in an asymptomatic 70-year-old woman with a positive family history of breast cancer. This woman was diagnosed through radiological screenings, including mammograms, ultrasonography, and magnetic resonance imaging (MRI). On histopathologic examination of the core biopsy, the left breast mass was a Nottingham grade I invasive carcinoma of no particular type. The right breast mass was a Nottingham grade I invasive carcinoma with a mucinous component. After lumpectomies ultrasonography of the surgical specimens confirmed a small biopsy-proven invasive ductal cancer hypoechoic mass in the left breast, with an irregular margins and proven mucinous cancer mass in the right breast. The case was finally diagnosed as synchronous bilateral breast cancer of different pathologic types (ductal and mucinous).

Trial of a Rare Diagnosis in a Core Needle Biopsy of Breast

Objective:

Mucinous carcinoma is a rare, special subtype of breast carcinoma associated with a good prognosis. It often presents a confusing appearance with a benign process. For all these reasons, differential diagnosis could be challenging.

Case Report:

Eighty years-old woman with a soft, lobulated, and well circumscribed mass at the left breast mimicking a benign process. Pathological examination of a core needle biopsy showed pure mucinous carcinoma.

Discussion:

It is a disease of elderly patient, over 60 years, and usually occurs in postmenopausal women. It accounts for only 2% of total breast carcinomas. On pathologic analysis, to be defined as pure mucinous carcinoma, a carcinoma must be made up of at least 90% intracellular or extracellular mucin.

Conclusion:

Examination of core biopsy material should be done carefully respecting this criteria to confirm the diagnosis of this rare entity and eliminate differential diagnosis.

Mucinous Breast Carcinoma Presenting as a Coarse and Densely Calcified Mass on Mammography: A Case Report

We report herein a 46-year-old woman who presented with mucinous breast carcinoma that appeared as a coarse and densely calcified mass on mammography. The lesion was a 4.6-cmsized palpable, hyperechoic, calcified mass with posterior shadowing on ultrasonography. This finding is a unique feature of mucinous breast carcinoma and is also observed in unusual breast cancer variants such as metaplastic breast cancer with chondroid differentiation, extraosseous osteosarcoma, and breast chondrosarcoma. The lesion showed a slow-growing pattern throughout the 4-year observation period. Mammography performed 4 years ago revealed faint, grouped microcalcifications; the lesion increased in size over 2 years, presenting as a well-circumscribed, calcified mass, mimicking dystrophic calcification. As several unusual variants of breast cancer, including mucinous carcinoma, may present as coarse and densely calcified masses on mammography, immediate biopsy should be considered when they are observed.

Imaging features of pure mucinous breast carcinoma: correlation with extracellular mucus content

AIM

To analyse the correlation between imaging features using multiple techniques and extracellular mucus content in pure mucinous breast carcinoma (PMBC).

MATERIALS AND METHODS

A retrospective review of available images from 25 patients with 25 PMBC tumours was conducted, with ultrasonography (US), ultrasonic elastography (USE), mammography, and breast-specific gamma imaging (BSGI) available for 25, 15, 11, and eight patients, respectively. Microscopic slides from each tumour were evaluated for extracellular mucus content. The correlation between imaging features and mucus content was analysed using linear-by-linear association chi-square tests or Spearman's rank correlation analyses.

RESULTS

On US images, a significant correlation was found between mucus content and echo pattern (p=0.042) and colour Doppler blood flow (p=0.032), with a trend that the lower mucus content present in tumours, the more likely they were detected with isoechoic echo and high blood flow. On USE images, a moderate negative correlation (r=-0.60, p=0.029) was observed between mucus content and tumour stiffness. On BSGI images, a strong negative correlation (r=-0.92, p=0.001) was shown between mucus content and lesion to non-lesion ratio (L/N) values of radioactivity counts. No significant correlation was found between mucus content and mammography imaging features (all p>0.05).

CONCLUSION

Imaging features at US, USE, and BSGI correlated with extracellular mucus content in PMBC tumours, among which the L/N value using BSGI imaging is the most relevant feature.

Invasive Colloid Carcinoma and the role of Ki-67 and HER2 - Two case reports

Mucinous carcinoma (also termed colloid carcinoma) of the breast accounts for 1%-6% of all breast cancer and is considered to have a good relative prognosis. The most common mammographic appearance of pure mucinous carcinoma is a high-density mass with circumscribed margins and on sonographic examination an isoechoic round mass with circumscribed margins. We report 2 cases of invasive mucinous carcinoma, in which one patient showed an intermediate recurrence risk based on Ki-67 and human epidermal growth factor receptor 2 negativity, while the other showed a low Ki-67 recurrence risk and human epidermal growth factor receptor 2 positive. We also review the literature on Ki-67 and human epidermal growth factor receptor 2 and explore the roles of these molecular markers in mucinous carcinomas.

Hyperechoic breast images: all that glitters is not gold!

Abstract

Hyperechogenicity is a sign classically reported to be in favour of a benign lesion and can be observed in many types of benign breast lesions such as hamartoma, lipoma, angiolipoma, haemangioma, haematoma, fat necrosis, fibrosis and galactocele, among others. However, some rare malignant breast lesions can also present a hyperechoic appearance. Most of these hyperechoic malignant lesions present other characteristics that are more typically suggestive of malignancy such as posterior shadowing, a more vertical axis or irregular margins that help to guide the diagnosis. Post magnetic resonance imaging, second-look ultrasound may visualise hyperechoic malignant lesions that would not have been identified at first sight and radiologists must know how to recognise these lesions.

Teaching Points

• Some rare malignant breast lesions can present a hyperechoic appearance.

• Malignant lesions present other characteristics that are suggestive of malignancy.

• An echogenic mass with fat density on mammography does not require biopsy.

Quantitative microscopic evaluation of mucin areas and its percentage in mucinous carcinoma of the breast using tissue histological images

Mucinous carcinoma (MC) of the breast is very rare (∼1-7% of all breast cancers), invasive ductal carcinoma. Presence of pools of extracellular mucin is one of the most important histological features for MC. This paper aims at developing a quantitative computer-aided methodology for automated identification of mucin areas and its percentage using tissue histological images. The proposed method includes pre-processing (i.e., colour space transformation and colour normalization), mucin regions segmentation, post-processing, and performance evaluation. The proposed algorithm achieved 97.74% segmentation accuracy in comparison to ground truths. In addition, the percentage of mucin present in the tissue regions is calculated by the mucin index (MI) for grading MC (pure, moderately, minimally mucinous).

Interactive case review of radiologic and pathologic findings from breast biopsy: are they concordant? How do I manage the results?

The number of imaging-guided percutaneous breast biopsies performed has steadily increased as imaging techniques have improved. Percutaneous biopsy is becoming more commonplace and supplanting excisional biopsy as the preferred diagnostic tool. The radiologist's role in caring for patients who undergo breast biopsy extends beyond imaging to identifying lesions for biopsy and then performing the procedure. Radiologists must also be cognizant of radiologic-pathologic correlation to determine whether biopsy results are concordant with imaging findings and make management recommendations. Management of microcalcifications, masses, and areas of asymmetry begins with recognizing and characterizing the findings with the proper Breast Imaging Reporting and Data System (BI-RADS) lexicon. Determining concordance between imaging findings and histologic results is equally important. The decision to recommend surgical excision or short-term follow-up relies heavily on whether the histologic diagnosis correlates with the imaging findings, a determination that is part of the radiologist's responsibilities if he or she performs the biopsy. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.334125123/-/DC1.

Mucinous carcinoma of the breast: iconographic essay with histopathological correlation

The present essay is aimed at describing the most characteristic imaging findings of mucinous carcinoma of the breast, with emphasis on the patterns related to better prognosis. The authors selected cases of mucinous carcinoma of the breast whose images were available, highlighting the imaging findings suggestive of this subtype of breast cancer, either at mammography, ultrasonography or magnetic resonance imaging.

Invasive mucinous carcinoma of the breast

Mucinous carcinoma of the breast is one of the rarer forms of intramammary cancer, often presenting as a lobulated, fairly well circumscribed mass on mammography, sonography, and gadolinium-enhanced magnetic resonance imaging. It accounts for 1% to 7% of all breast cancers and generally carries a better prognosis than other types of malignant breast cancers. Metastatic disease occurs at a lower frequency than in other types of invasive carcinoma. We present an atypical case of mucinous carcinoma in a woman who presented with a palpable intramammary lymph node metastasis from an unknown breast primary. Subsequent magnetic resonance imaging and percutaneous biopsy demonstrated histologic findings consistent with a mixed mucinous neoplasm with a micropapillary pattern.

Inhibitors targeting mitosis: tales of how great drugs against a promising target were brought down by a flawed rationale

Although they have been advocated with an understandable enthusiasm, mitosis-specific agents such as inhibitors of mitotic kinases and kinesin spindle protein have not been successful clinically. These drugs were developed as agents that would build on the success of microtubule-targeting agents while avoiding the neurotoxicity that encumbers drugs such as taxanes and vinca alkaloids. The rationale for using mitosis-specific agents was based on the thesis that the clinical efficacy of microtubule-targeting agents could be ascribed to the induction of mitotic arrest. However, the latter concept, which has long been accepted as dogma, is likely important only in cell culture and rapidly growing preclinical models, and irrelevant in patient tumors, where interference with intracellular trafficking on microtubules is likely the principal mechanism of action. Here we review the preclinical and clinical data for a diverse group of inhibitors that target mitosis and identify the reasons why these highly specific, myelosuppressive compounds have failed to deliver on their promise.

Imaging findings and accuracy of core needle biopsy in mucinous carcinoma of the breast

BACKGROUND

Diagnosis of mucinous carcinoma can be difficult due to its benign appearance on mammograms and ultrasonographic (US) images. In the light of the rather scarce literature, core needle biopsy (CNB) has proved useful in diagnosing mucinous lesions.

PURPOSE

To assess mammographic, US, and CNB findings of mucinous breast tumors and to correlate them with final histology obtained in therapeutic surgery.

MATERIAL AND METHODS

From 2000-2006, 25 mucinous carcinomas detected with CNB were surgically removed. The mammography, US, and CNB results were analyzed and correlated with final histology.

RESULTS

Ninety-six percent of the mucinous carcinomas (24/25) were visible with US. All except two of the 24 tumors were solid masses. All the mixed-type lesions (group 2) were hypoechoic and had irregular or lobulated margins and heterogeous internal echotexture. The US features were more variable among the 14 pure mucinous carcinomas (group 1) and the six US visible mucinous carcinomas with cancerous cells outside the tumor (group 3). Fifty-seven percent of group 1 and 50% of group 3 tumors had clearly lobulated or irregular margins. Fifty-seven percent of group 1 and 67% of group 3 cancers were hypoechoic. A vast majority of these tumors had heterogenous echotexture. Seventy-one percent (17/24) of the lesions visible with US had posterior acoustic enhancement. Eighty percent (20/25) of the mucinous carcinomas were classified as BI-RADS 4 lesions in US. All the lesions with images available were visible on mammograms, where most of the tumors were seen as a high-density circumscribed lesion and classified as BI-RADS 4 lesions, while none were classified as BI-RADS 1, 2 or 5. The sensitivity and positive predictive value of CNB regarding mucinous carcinoma was 100%.

CONCLUSION

CNB was found to be a highly reliable diagnostic tool for diagnosing mucinous carcinoma in this selected material. US findings of pure mucinous carcinoma were variable, however, all reached BI-RADS 4 category. The presence of posterior acoustic enhancement beneath a solid breast lesion should raise suspicion of mucinous carcinoma. Most of the tumors appeared as BI-RADS 4 lesions in US and in mammography thus making both a useful tool for raising a suspicion of malignancy in mucinous cancers.

Imaging findings in mucinous breast carcinoma and correlating factors

OBJECTIVE

To investigate the factors influencing mammographic and sonographic features of mucinous breast carcinoma.

MATERIALS AND METHODS

Forty-six patients diagnosed as mucinous breast carcinoma between March 2005 and April 2009 were studied. Mammographies of all patients and sonographies of 41 patients were analyzed retrospectively. Microscopic slides were re-evaluated by a pathologist in order to estimate the volume of extracellular mucus which was classified as: (+), less than 50% of mucus; (++), 50-80% of mucus; and (+++), more than 80% of mucus.

RESULTS

Thirty-one (61.3%) cases of pure mucinous type and 2 (33.3%) of mixed mucinous carcinoma presented as masses had well-defined margins on mammography. No correlation was found between margin characteristics and histological type as well as extracellular mucus rates. Denser breasts and young age group had significantly higher ratios of tumors presented with ill-defined masses than its counterpart. Sonographically, 100% lesions showed a hypoechoic lesion, 76.5% lesions in pure type and 71.4% lesions in mixed type showed a heterogeneous internal echo. No correlation was found between sonographic findings and histological type as well as extracellular mucus rates. Lesions with >40 positivity PCNA had higher ratio presented as ill-defined margins than those of ≤40% positivity PCNA.

CONCLUSIONS

The most common appearance of mucinous breast carcinoma is a mass on mammography and a hypoechoic lesion with heterogeneous internal echo on sonography. Mammographic margins and sonographic findings have no relation with histological type and extracellular mucus rate. Mammographic margin features are correlated with breast density and age and PCNA.

[Pure colloid carcinoma of the breast: anatomoclinical study of seven cases]

PURPOSE

Breast mucinous carcinoma is a particular histological form characterized by the extracellular production of mucus. The pure form is rarely reported and its prognostic is better than the other types of the breast cancer. The aim of the present study was to discuss the various anatomoclinical, therapeutic aspects and the prognostic factors of the pure mucinous carcinoma of the breast.

PATIENTS AND METHODS

We report seven cases diagnosed over a period of 11 years (1993-2003) in the laboratory of anatomy and pathological cytology of the university hospital of Sfax. A review of the clinical files with immunohistochemistry study (hormonal receptor, synaptophysine, chromogranine, Bcl2, Ki67, P53 and Her-2/neu (C-erbB-2)) were carried out for all the cases.

RESULTS

pure colloid carcinoma of the breast accounted for 0,5% of the whole of the breast cancers. The average age of patients was 69 years. At the time of the diagnosis, four tumours were classified T4, one T3, two T2, two N1 and one N3; no patient had presented metastasis (M0) according to pTNM classification. The echomammography showed regular contours mass in four cases. The anatomopathological study showed that the neuroendocrine differentiation was found in two cases, all the tumours had presented positivity for the hormonal receptors (oestrogen and progesterone) and negativity for the other antibodies, two cases exhibited the Bcl2 positivity and negativity for the other antibodies. An adjuvant radiotherapy was carried out for all the patients. The average duration of follow-up was of 33 months; the evolution was marked by the occurrence of metastases in two cases.

CONCLUSION

The pure colloid carcinoma of the breast constitutes a particular morphological entity which deserves to be individualized; neuroendocrine differentiation of these tumours must be required. Their forecast is relatively favourable.

Imaging differences in metaplastic and invasive ductal carcinomas of the breast

OBJECTIVE

The purpose of this study was to compare the imaging features of metaplastic breast carcinoma with those of invasive ductal carcinoma.

MATERIALS AND METHODS

Women diagnosed on preoperative mammography or sonography with metaplastic breast carcinoma and T-stage matched invasive ductal carcinoma of the breast from a single pathology database were included in the study. Clinical and pathologic information on all metaplastic cancers was documented. Mammography and sonography variables were recorded using the BI-RADS lexicon. Groups were compared using Fisher's exact test, the chi-square test, or Wilcoxon's rank sum test, as appropriate.

RESULTS

Forty-three patients diagnosed with metaplastic carcinoma were matched to 43 patients with ductal carcinoma by tumor T stage. Patients with metaplastic carcinoma were younger (median, 46 vs 53 years, p = 0.048) than those with ductal carcinoma. Mammographically, metaplastic carcinomas were less frequently irregular in shape (16% vs 74%, p < 0.0001) and less frequently showed microlobulated or spiculated margins (19% vs 56%, p = 0.0008) and calcifications (25% vs 51%, p = 0.02) when compared with ductal carcinomas. Sonographically, metaplastic carcinomas were less frequently irregular in shape (27% vs 69%, p = 0.001) and less frequently showed angular margins (9% vs 49%) and posterior acoustic shadowing (9% vs 49%, p < 0.0001).

CONCLUSION

Characteristic malignant imaging features, including irregular shape, spiculated margins, segmentally distributed pleomorphic calcifications, and posterior acoustic shadowing, are uncommon in metaplastic carcinomas. These carcinomas tend to show more benign imaging features, such as round or oval shape with circumscribed margins, when compared with ductal carcinomas.

Screen-detected mucinous breast carcinoma: potential for delayed diagnosis

AIM

To describe the imaging features of 34 screen-detected mucinous carcinomas lesions.

MATERIALS AND METHODS

The BreastScreen Western Australia (WA) database between January 1991 and December 2003 was searched. During this period, 214,507 women were screened and 2745 cases of invasive carcinoma and 45 cases of mucinous carcinoma were recorded. Case notes, radiology films and pathology reports of patients with mucinous carcinoma were reviewed. Thirty-four radiologically detected pure mucinous carcinomas are described.

RESULTS

Of the pure mucinous carcinomas, the average age at diagnosis was 65 years (range 48-82 years), which was higher than that of other women with breast cancer (average age 60 years) screened at BreastScreen WA. Characteristic mammographic features of mucinous carcinoma are well-circumscribed masses with lobulated margins (26/34). Only 39% (11/28) of tumours were detected at ultrasound, as the smaller lesions less than 15mm in diameter were often isoechoic with normal fat. Where histological grade was reported at excision, most (25/26) were low to medium-grade tumours (Bloom, Richardson and Elston grade I and II). A significant number of lesions (13/34) were evident on the previous screening examination where they were misinterpreted as benign lesions. However, none of these cases had positive axillary lymph nodes at final diagnosis.

CONCLUSION

Although mammographically benign appearances of mucinous carcinoma caused a delay in diagnosis in 38% of the present cases, mucinous breast carcinomas have a favourable prognosis, as they are often low-grade tumours and rarely metastasize. Delay in diagnosis for these tumours in a screening programme may not lead to a significant adverse outcome for most women.

Role of fine needle aspiration and tru cut biopsy in diagnosis of mucinous carcinoma of breast—from a radiologist's perspective

This study was to assess whether fine needle aspiration (FNA) or core biopsy would allow diagnosis of mucinous carcinoma of breast. In 37 mucinous carcinoma in 34 patients, 20 lesions had FNA and 24 lesions with core biopsy. FNA achieved a sensitivity of 66.7% in diagnosis of malignant lesions and 56% sensitivity in diagnosis of mucinous carcinoma. Core biopsy achieved 100% sensitivity and accuracy in the diagnosis of malignant lesions and mucinous carcinoma.

Stellate images: anatomic and radiologic correlations

The stellate images are the most well-known and most typical finding in the diagnosis of breast cancer. Its positive predictive value is very high. However, in some cases, the stellate images can correspond to benign lesions. Stellate images require high quality mammograms, precise analysis, and as always in senology, confirmation by clinical examination, ultrasound if necessary, and in the case of palpable lesions, cytology. In this work, we will study malignant and benign stellate images mammographic-pathologic correlation as well as the importance of stellate images in the detection of non-palpable lesions. The typical stellate finding is correlated with the phenomena of fibrosis and elastosis and it is impossible to distinguish benign spicules from malignant spicules on mammography. We will present guidelines in the face of stellate image. Stellate images are for the most part suggestive of malignant lesions, and their discovery should lead to suspicion of cancer until the contrary is proven.

Mucocele-like Lesions of the Breast: A Benign Cause for Indeterminate or Suspicious Mammographic Microcalcifications

Most earlier reports of mucocele-like lesions (MLL) of the breast have dealt with symptomatic cases in premenopausal women or lesions found incidentally in breast biopsies performed for other reasons. The diagnosis of this lesion has special challenges in the setting of mammographic screening for breast cancer because the imaging characteristics of MLL may mimic those of ductal carcinoma in situ (DCIS), while mucinous carcinoma enters the differential diagnosis on cytologic grounds. This report focuses on our experience with MLLs detected during screening mammography. Cases with MLL as the final histologic diagnosis in our database during January 1992-June 2000 are included. The results of clinical, imaging, cytologic, core biopsy, and histologic examination of these lesions are recorded. The relevant literature is reviewed. Twenty-six cases were found, with a mean patient age of 57.5 years. Microcalcifications were the dominant radiologic abnormality in 22 cases (84.6%). Imaging was considered suspicious or almost certainly malignant in 17 cases (65.4%). Cytology was classified as atypical or suspicious in 17 cases (70.9%). However, open biopsy showed mostly benign changes, including atypical ductal hyperplasia (ADH) in five cases (19.2%). In one case, ADH merged with a 3-4 mm focus of low-grade DCIS. This, the largest series focusing purely on screen-detected MLL, suggests that the combination of clinical, imaging, and cytologic features of screen-detected MLL are different from those of mucinous carcinoma, symptomatic MLL, or incidental MLL. Correlating the cytomorphology of mucinous lesions of the breast with their mammographic appearance may permit more precise preoperative diagnosis.

Sonographic Appearance of Mucinous Carcinoma of the Breast

OBJECTIVE

The aim of this study was to evaluate the sonographic and mammographic features of mucinous carcinoma and to correlate the imaging features with two histologic classifications.

MATERIALS AND METHODS

Two radiologists analyzed the mammographic and sonographic features of 33 mucinous carcinomas. Mammographic features according to the Breast Imaging Reporting and Data System (BI-RADS) and sonographic features were recorded and analyzed. The imaging features of the mass were correlated with the nuclear grade and mucin content of these 33 mucinous carcinomas. The incidence of axillary lymph nodes metastasis in different histologic grades and their detection by imaging were also assessed.

RESULTS

As many as 21.2% (7/33) of mucinous carcinomas could not be detected mammographically. When they were detected mammographically, more than 92% of the tumors presented as a mass, either oval or lobular. Microlobulations were present in 38.5% of these lesions. The margin of the lesion as seen on mammography can be used to predict the histologic grade. A circumscribed margin was associated with a favorable histologic grade (p = 0.01), whereas an indistinct margin was more commonly associated with the mixed type of lesion (p = 0.05). Sonographically, mixed cystic and solid components, distal enhancement, and microlobulated margins were commonly found in mucinous carcinomas, with an incidence of 37.5%, 43.8%, and 56.3%, respectively. Homogeneity on sonography was associated with the pure type of mucinous carcinoma and hence a better prognosis. Sonography showed a sensitivity of 50%, specificity of 89%, positive predictive value of 60%, negative predictive value of 84%, and accuracy of 79.2% in the detection of axillary lymph node metastasis.

CONCLUSION

Both sonographic and mammographic assessments are important in the correct diagnosis of mucinous carcinoma, the prediction of histologic grade, and the prognosis of the tumors.

Original report. Mucocele-like tumors of the breast: mammographic and sonographic appearances

OBJECTIVE

The purpose of our study was to describe the mammographic and sonographic appearances of the mucocele-like tumor of the breast.

CONCLUSION

The mucocele-like tumor is a rare lesion of the breast, the benign form of which has a nonspecific mammographic appearance. The tumor can present as indeterminate microcalcifications or as a nodule, often containing calcifications. The sonographic findings are of multiple well-defined hypoechoic oval or tubular structures with low-level internal echoes resembling complex cysts. Mucocele-like tumors of the breast can be associated with atypical hyperplasia or carcinoma. If a mucocele-like tumor is diagnosed at core needle biopsy, complete surgical excision is recommended, with careful evaluation of the entire specimen to exclude the presence of atypia or carcinoma.

Incidental finding of a mucinous carcinoma of the breast by dynamic MRI in a patient with a history of breast trauma (horse bite): incidental mucinous carcinoma after breast trauma

Occasional reports on the coincidence of previous trauma of the breast and the development of invasive breast cancer have been published. Furthermore, traumatic changes of the breast tissue can clinically and radiographically mimic malignant breast disease. We report of a 52-year-old female presenting with increasing mammographic microcalcifications after a trauma of the breast due to a horse bite. Dynamic MRI was able to exclude malignancy at the site of the trauma but did detect a clinically and radiographically nonsymptomatic mucinous carcinoma of the breast.

Mucinous (colloid) breast cancer: mammographic and US features with histologic correlation

OBJECTIVE

Mucinous carcinoma of the breast presents with different survival rates in pure and mixed types. The purpose of this study was to correlate the mammographic and ultrasonographic findings of mucinous carcinoma with histologic features in different types and mucin rates.

MATERIAL AND METHODS

Thirty-four patients (2.3%) had mucinous cancer after retrospective review of the 1439 breast cancers diagnosed between 1990 and 1996. Twenty-seven patients, 19 pure and eight mixed type of mucinous carcinomas of the breast, were included in this study to evaluate the imaging findings. In 22 of these, the microscopic slides were available and re-evaluated to estimate the volume of extracellular mucin. The volume of the extracellular mucin was classified histologically as: (+), less than 50% of mucin; (++), 50-80% of mucin; and ( ), more than 80% of mucin. Mammographic features with emphasis on margin characteristics and sonographic echo pattern of tumors were correlated with histologic findings.

RESULTS

Ten cases (53%) of pure mucinous type carcinomas had a circumscribed mass lesion on the mammograms. The well-defined, lobulated margins of the masses were well correlated with pure histologic type (P<0.01; chi(2) analysis) Two-thirds of these tumors had high volume extracellular mucin. All mixed type mucinous carcinomas demonstrated poorly defined or spiculated margins with no relation to the mucin rates (P<0.01). The sonographic appearances of the tumors showed correlation with histologic types. Most of the pure type carcinomas (53%) were seen with isoechogenic echo texture relative to that of subcutaneous fat, while all of the mixed type carcinomas were hypoechogenic (P<0.01).

CONCLUSION

The mammographic and sonographic features of mucinous breast carcinoma show differences in pure and mixed types of the tumor. The most common mammographic appearance of pure mucinous carcinomas with high percentages of mucin is a mass lesion having well-defined margins, which is isoechogenic relative to fat on the sonographic examination. Pure type of carcinomas with small percentages of mucin and mixed type carcinomas have more aggressive imaging characteristics.

Correlation between ultrasound characteristics, mammographic findings and histological grade in patients with invasive ductal carcinoma of the breast

AIM

To investigate the relationship between ultrasound characteristics, mammographic findings and histological grade in cases of invasive ductal carcinoma which produce a mass on ultrasound.

MATERIAL AND METHODS

A retrospective review was performed of the imaging findings in 120 patients diagnosed with invasive ductal carcinoma of the breast between January 1996 and December 1997. Imaging findings were correlated with the histological grade of tumour.

RESULTS

High-grade tumours were significantly larger both on ultrasound and mammography (P < 0.016). A spiculated margin on mammogram was documented in 72% of low-grade tumours compared with only 24% of high-grade tumours (P = 0.001). Twenty-two per cent of low-grade tumours had a poorly defined margin on mammography compared with 66% of high-grade tumours (P = 0.001). At ultrasound, 16% of high-grade tumours (95% confidence limits 7-29%) had a well-defined margin. Acoustic enhancement was seen in 36% of high-grade tumours compared with only 9% of low and intermediate-grade tumours (P = 0.003): 22% of all tumours showed acoustic enhancement. Acoustic shadowing was seen in 71% of low-grade tumours compared with only 28% of high-grade tumours (P = 0.003). Malignant-type microcalcification was seen on mammogram in 6% of low-grade tumours compared with 31% of high-grade tumours (P = 0.045).

CONCLUSION

The classical appearance of a malignant breast mass as a spiculated mass on mammogram associated with acoustic shadowing on ultrasound is more typical of a low-grade tumour. In comparison, high-grade tumours are more likely to demonstrate posterior acoustic enhancement, and a proportion has a well-defined margin on ultrasound. Therefore, high-grade invasive ductal carcinoma may paradoxically display similar imaging features to a benign breast mass.

Pure mucinous breast cancer-mammographic and ultrasound findings

Aim to describe the mammographic and ultrasonographic features of pure mucinous breast cancer.

PATIENTS AND METHODS

The mammographic features of 15 patients and ultrasonographic features of seven patients with pure mucinous breast cancer were reviewed retrospectively by three experienced breast radiologists.

RESULTS

The commonest mammographic appearance was of a poorly defined (86%) lobulated (71%) mass which could contain calcification (14%). A well defined mass (14%) and suspicious calcifications without a mass (7%) were also seen. Ultrasound showed a mass lesion in all seven cases which was either hypoechoic (86%) or mixed echogenicity (14%); 86% had a heterogeneous internal echo pattern; 71% showed distal enhancement while none showed distal attenuation.

CONCLUSION

The imaging features of pure mucinous cancer are different from more common types of breast carcinoma. It is possible to misinterpret the appearances of this slow growing tumour as a benign lesion due to rarity of speculation on mammography and distal attenuation on ultrasonography. Most cases do, however, show other features suggesting malignancy.