Characteristics and chronologically changing patterns of late-onset breast cancer in Korean women of age ≥ 70 years: A hospital based-registry study.

BACKGROUND: Women from Asian and western countries have vastly different ages of onset of breast cancer, with the disease tending to occur at an older age in the West. Through an investigation of the patterns of old-onset breast cancer (OBC) in Korean women, we aimed to identify the characteristics of Korean OBC and evaluate whether these patterns are changing in relation to increasing westernization. METHODS: This study retrospectively evaluated 102,379 patients who underwent surgical treatment of primary breast cancer between January 1, 2000 and December 31, 2013 in Korea. We used hospital -based breast cancer registry and analyzed data from these patients using multiple linear regression analysis to compare the characteristics and chronologically changing patterns between OBC (70 years of age or older) and non-OBC (40-69 years of age) patients in Korea. RESULTS: A total of 6% of the 102,379 patients had OBC. Overall, OBC had more favorable biological features, such as a higher incidence of luminal A subtype, than did non-OBC, except for a higher incidence rate of triple-negative breast cancer (TNBC). However, OBC also presented with a higher overall disease stage, including higher T and M stages. Although the incidence rates of both OBC and non-OBC have increased overtime, the relative proportion of OBC patients has slightly increased, whereas that of non-OBC has slightly decreased. The increase in the incidence of both OBC and non-OBC was primarily due to the luminal A subtype. CONCLUSIONS: Based on a hospital-based registry, overall, Korean OBC had favorable biological features but showed a higher rate of TNBC and advanced cancer stages. The incidence trend of breast cancer in Korea is slowly shifting toward an older age at onset, largely due to the luminal A subtype. Our results may provide novel insights into OBC in Asia, and aid in the development of optimal management of the disease in Asia. TRIAL REGISTRATION: Retrospectively registered.

Intraobserver and interobserver reliability in sonographic size measurements of gallbladder polyps.

OBJECTIVES: To evaluate the intraobserver and interobserver reliability of gallbladder polyp measurements using transabdominal US and the factors that affect reliability. METHODS: From November 2017 to February 2018, two radiologists measured the maximum diameter of 91 gallbladder polyps using transabdominal US. Intraobserver and interobserver agreement were determined using 95% Bland-Altman limits of agreement and intraclass correlation coefficients (ICCs). The effects of image settings, polyp location, and polyp size were evaluated by comparing ICCs using z tests. RESULTS: The intraobserver agreement rates were 0.960 (95% confidence interval [CI], 0.939-0.973) for observer 1 and 0.962 (95% CI, 0.943-0.975) for observer 2. The ICCs between the two observers were 0.963 (95% CI, 0.926-0.979) for the first measurement and 0.973 (95% CI, 0.950-0.984) for the second measurement. The 95% limits of agreement on repeated measurements were 22.3-25.2% of the mean, and those between the two observers were 25.5-34.2% of the mean. ICCs for large polyps (≥ 5 mm) were significantly higher than those for small polyps (< 5 mm). There were no significant differences in the ICCs between image settings and polyp location. CONCLUSIONS: Polyp size measurements using transabdominal US are highly repeatable and reproducible. Polyp size significantly affects the reliability of measurement. Diameter changes of approximately less than 25% may fall within the measurement error; this should be considered while interpreting the change in size during follow-up US, especially for small polyps. KEY POINTS: • Gallbladder polyp size measurement using transabdominal US is highly repeatable and reproducible. • Diameter changes of approximately less than 25% should be interpreted carefully, especially in small polyps.

Ultrasound Features and Rate of Upgrade to Malignancy in Atypical Apocrine Lesions of the Breast.

OBJECTIVES: To evaluate the ultrasound (US) features and rate of upgrade to malignancy in atypical apocrine lesions (AALs) of the breast, diagnosed on percutaneous needle biopsy. METHODS: This retrospective study included 17 AALs diagnosed by needle biopsy in 15 patients. For 16 of the 17 AALs, subsequent surgical excision (n = 14) or 8-gauge vacuum-assisted biopsy (n = 2) was performed. Ultrasound features were retrospectively analyzed according to the American College of Radiology Breast Imaging Reporting and Data System lexicon. RESULTS: Of 17 AALs, 13 (76.5%) were atypical apocrine hyperplasia; 3 (17.6%) were atypical apocrine adenosis; and 1 (5.9%) was combined atypical apocrine hyperplasia and atypical apocrine adenosis on needle biopsy. Subsequently, 4 of 16 AALs (25%) were upgraded to malignancy at surgical excision. On US imaging, all 17 lesions presented as masses, which were mainly irregular and noncircumscribed (n = 8) or oval/round and noncircumscribed (n = 7) with isoechogenicity or hypoechogenicity. Rarely, an AAL would show complex cystic and solid echogenicity (n = 1) or appear as a hypoechoic mass with oval shape and a circumscribed margin (n = 1). CONCLUSIONS: Atypical apocrine lesions of the breast often showed suspicious malignant features on US imaging. Given the high upgrade rate (25%), the diagnosis of an AAL by needle biopsy warrants subsequent surgical excision.

Cervical Lymph Node Imaging Reporting and Data System for Ultrasound of Cervical Lymphadenopathy: A Pilot Study.

OBJECTIVE: The objective of our study was to compare ultrasound (US) and real-time elastography (RTE) features of benign and malignant cervical lymphadenopathies and propose a structured reporting system for lymph nodes. MATERIALS AND METHODS: The study population for this retrospective study consisted of 291 consecutive patients who underwent US-guided biopsies for cervical lymphadenopathy between 2013 and 2014. The following imaging features were analyzed: shape, margin, echogenicity, echogenic hilum, gross necrosis, calcification, matting, intranodal vascular pattern, elasticity scores (four categories), and strain ratio. A score was assigned for each significant factor from a logistic regression analysis and was multiplied by the beta coefficient. The fitted probability of malignancy was calculated. The risk of malignancy was determined on the basis of the number of suspicious features. Interobserver agreement of the imaging features was retrospectively analyzed using a coefficient of interrater agreement. RESULTS: The imaging features that were significantly associated with malignant lymphadenopathy were round shape, noncircumscribed margin, hyperechogenicity, absence of hilum, gross necrosis, calcification, peripheral or mixed vascularity, high elasticity scores, and high level of strain ratio (p < 0.05). The fitted probability and risk of malignancy increased as the number of suspicious features increased. The risk of malignancy according to the Cervical Lymph Node Imaging Reporting and Data System categories was as follows: category 1, 3.3%; category 2, 10.9%; category 3, 26.7%; category 4, 51.8-74.4%; and category 5, 90.6-98.8%. An analysis of the overall interobserver agreement revealed that interobserver agreement was moderate to good. CONCLUSION: We propose the Cervical Lymph Node Imaging Reporting and Data System, which uses the number of suspicious US and RTE features to assess the risk of malignancy in cervical lymph nodes.

Apparent diffusion coefficient for lymph node characterization after chemoradiation therapy for locally advanced rectal cancer.

BACKGROUND: Because further treatment plans depends on lymph node (LN) status after neoadjuvant chemoradiation therapy (CRT), the accurate characterization of LN is important. PURPOSE: To evaluate the diagnostic performance of apparent diffusion coefficient (ADC) for LN characterization after CRT and to compare the performance with that of LN size. MATERIAL AND METHODS: Fifty-three patients (36 men, 17 women; mean age, 58 years; age range, 34-79 years) who underwent CRT and subsequent surgery were included. All patients underwent 1.5-T magnetic resonance imaging (MRI). Each regional LN on post-CRT MRI was identified in consensus by two radiologists after reviewing the pre-CRT MRI. The ADC value and size in each LN was measured. To compare the mean ADC values and sizes of the metastatic and non-metastatic LNs after CRT, the t-test was used. To calculate the performance, a ROC curve analysis was performed. The histopathological examinations served as the reference standard. RESULTS: A total of 115 LNs (29 metastatic and 86 non-metastatic) were matched and analyzed. The mean ADC of the metastatic LNs was significantly higher than that of the non-metastatic LNs (1.36 ± 0.27 × 10(-3)mm(2)/s; 1.13 ± 0.23 × 10(-3)mm(2)/s, P < 0.0001). The mean size of the metastatic LNs was also significantly larger than that of the non-metastatic LNs (5.6 ± 3.1; 3.9 ± 1.2, P = 0.0078). There was no significant difference between the areas under the curve of the ADC and size (0.742 [95% CI, 0.652-0.819]; 0.680 [0.586-0.764], respectively, P = 0.4090). CONCLUSION: The performance of ADC for LN characterization after CRT was comparable to that of LN size.

Clinical Importance and Sonographic Features of Nonpalpable Axillary Lymphadenopathy Identified on Breast Sonography in Patients Without Malignancy.

OBJECTIVES: The purpose of this study was to evaluate the clinical importance and sonographic features of nonpalpable axillary lymphadenopathy identified on breast sonography in patients without malignancy. METHODS: Our study included 71 women and 2 men (mean age, 47.5 years; range, 16-69 years) with axillary lymphadenopathy identified on breast sonography. None of the 73 patients had known malignancy or presented with palpable lymph nodes or symptoms of mastitis. The lesions were pathologically diagnosed in 53 patients by surgical biopsy (n = 8), ultrasound-guided core needle biopsy (n = 17), or ultrasound -guided fine needle aspiration (n = 28). Twenty patients underwent follow-up imaging for 6 to 60 months (mean, 17 months). The sonographic features of the axillary lymph nodes were analyzed for all patients. RESULTS: The final diagnoses included benign reactive hyperplasia (n = 45), Kikuchi disease (n = 4), tuberculosis (n = 3), and sarcoidosis (n = 1). None of the 20 patients who underwent follow-up imaging developed malignancy. Suspicious sonographic features were frequently observed (loss of the fatty hilum, round shape, abnormal cortical thickening, and marked hypoechogenicity: 79.5%, 75.3%, 82.1%, and 9.6%, respectively) and were mostly complex, with the most common combination being a round shape and loss of the fatty hilum in 61.6% patients. CONCLUSIONS: No malignancy was detected in all 73 patients, despite frequent manifestations of complex and extremely suspicious sonographic features. Short-term follow-up imaging rather than immediate biopsy can be recommended for nonpalpable lymphadenopathy in patients without known malignancy.

Gray-scale and color Doppler sonographic features of complex fibroadenomas of the breast.

PURPOSE: To investigate gray-scale and color Doppler sonographic (US) features of complex fibroadenoma (FA), according to the Breast Imaging-Reporting and Data System (BI-RADS) lexicon. METHODS: From 2010 through 2013, 586 women with FAs were seen; 101 (17%) of those lesions were diagnosed as complex FAs on percutaneous needle biopsy or surgery. Among the patients with complex FAs, 67 who had US examination results available were included in this study. In addition, the results from 98 women who had simple FAs were included as controls. US features were retrospectively analyzed by two breast radiologists in consensus for shape, margin, echogenicity, posterior acoustic pattern, boundary, orientation, and associated findings. They also reassessed the BI-RADS category for FAs. Color Doppler US examination results were classified according to the amount of vascularity as absent, moderate, or marked. RESULTS: Complex FA were larger than simple FAs were (14.5 cm versus 12.1 cm, p > 0.05). On univariate analysis, a round to irregular shape, an uncircumscribed margin, the presence of associated findings, and BI-RADS categorization as 4a and 4b were more frequently revealed in complex than in simple FAs (p < 0.05). Multivariate analysis revealed that the tumor margin was a predictive factor for complex FA (odds ratio: 6.08; 95% confidence interval: 1.14-32.49, p < 0.05). On color Doppler US, the complex FAs had higher degrees of vascularity than simple FA (p < 0.05). CONCLUSIONS: Complex FAs, in comparison with simple FAs, tend to have more aggressive features and to be in higher BI-RADS categories on US examination.

Fibromatosis associated with silicone breast implant: ultrasonography and MR imaging findings.

Desmoid type fibromatosis is an uncommon benign disease entity of which its etiology is currently unknown. It constitutes 0.3% of all solid neoplasms, but it is rarely seen in the breast and even more scarcely reported to develop in association with breast implant. We present ultrasonography and magnetic resonance imaging findings of a 29-year-old female patient with fibromatosis after breast implant surgery. Knowledge of imaging findings of breast fibromatosis associated with implant will be helpful for accurate diagnosis and appropriate management.

Nonmasslike lesions on breast sonography: comparison between benign and malignant lesions.

OBJECTIVES: To compare the imaging and clinical features of benign and malignant nonmasslike lesions in the breast. METHODS: During a 2-year period at a single institution, 186 nonmasslike lesions in 158 women were pathologically confirmed through surgery or sonographically guided biopsy. The sonographic patterns (mottled, geographic, and indistinct) and distributions (focal and regional) were compared between benign and malignant lesions. The presence of sonographically visible calcifications, amount of color Doppler signals, presence of positive findings on mammography, and presence of symptoms were also compared between the two groups. RESULTS: A total of 156 lesions (84%) were confirmed as benign and 30 (16%) as malignant. On sonography, malignant nonmasslike lesions more frequently had mottled and geographic patterns and regional distribution than benign lesions (P < .0001). Malignant lesions also more frequently had sonographically visible calcifications (40% versus 0%; P < 0.0001) and a greater amount of color Doppler signals than benign lesions (P < .0001). On mammography, malignant lesions more frequently had densities and calcifications than benign lesions (30.4% versus 7.1%; P = 0.0052; 73.9% versus 6.1%; P < .0001, respectively). Clinically, malignant lesions were more frequently palpable and accompanied by localized pain than benign lesions (50% versus 2.6%; P< .0001; 13.3% versus 0.6%; P = .0025). CONCLUSIONS: The imaging and clinical features of malignant nonmasslike lesions differed significantly from those of benign nonmasslike lesions.

Sonographic appearances of juvenile fibroadenoma of the breast.

OBJECTIVES: The purpose of this study was to evaluate characteristic features of juvenile fibroadenoma of the breast on sonography. METHODS: Our study included 34 juvenile fibroadenomas confirmed by surgical biopsy or sonographically guided 8-gauge vacuum-assisted biopsy in 23 patients (age range, 15-47 years; mean age, 25 years). Sonographic findings of the lesions were analyzed retrospectively by 2 radiologists in consensus according to the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) lexicon. The BI-RADS final assessment category was also established. RESULTS: On sonography, all fibroadenomas presented as masses. The mean size was 30 mm. Regarding shape, there were 29 oval, 2 round, and 3 irregular masses. The margins were circumscribed in 24, indistinct in 5, microlobulated in 4, and angular in 1. Regarding echogenicity, 16 masses were hypoechoic, 16 isoechoic, and 2 complex echoic. Posterior acoustic characteristics included posterior acoustic enhancement in 22 masses (65%), posterior shadowing in 1, and no posterior acoustic features in 9; this information was not available in 2. The lesion boundary presented as an abrupt interface in 32 and an echogenic halo in 2. The orientation was parallel in 32 and nonparallel in 2. Calcifications were present in 3 cases and absent in 31. On color Doppler sonography, the masses were usually hypervascular with vessel counts of 5 or more (87%). The BI-RADS final assessment categories were 3 in 24 and 4a in 10. CONCLUSIONS: The dominant sonographic presentation of juvenile fibroadenoma is a circumscribed oval hypoechoic or isoechoic mass, which resembles that of simple fibroadenoma. Juvenile fibroadenomas frequently show posterior acoustic enhancement and hypervascularity on color Doppler sonography.

Sonographic appearance of an intramuscular myxoma of the pectoralis major muscle.

Intramuscular myxomas are benign soft tissue tumors that usually involve skeletal muscle of the extremities; occurrence in the chest wall is extremely rare. We describe a case of intramuscular myxoma in the pectoralis major muscle of a 55-year-old woman. The patient presented with a palpable lump in her right breast. Mammography showed a circumscribed, oval, hyperdense mass within the pectoralis muscle. Ultrasonography showed a circumscribed, oval, complex mass within the pectoralis muscle.

Spontaneously infarcted fibroadenoma of the breast in an adolescent girl: sonographic findings.

Spontaneous infarction in fibroadenoma unrelated to any known risk factors is extremely rare. Here, I present a case of a spontaneously infarcted fibroadenoma in an adolescent girl in whom no plausible predisposing factors were identified. High-resolution sonographic imaging showed a unique circumscribed, complex echoic mass containing a frondular solid portion.

Pilomatricoma of the breast in an adolescent girl: sonographic findings.

I report a case of pilomatricoma of the breast in an adolescent girl. Sonograms showed a solitary circumscribed, oval, heterogeneously hyperechoic mass in the skin. This is the first description of sonographic findings for this rare tumor in an adolescent breast.

Sonographic findings of high-grade and non-high-grade ductal carcinoma in situ of the breast.

OBJECTIVE: The purpose of this study was to differentiate between high-grade and non-high-grade ductal carcinoma in situ (DCIS) of the breast on sonography. METHODS: From October 2003 to August 2009, 76 DCIS lesions in 73 women who underwent sonography and mammography were included in this study. Lesions were confirmed by mastectomy, breast-conserving surgery, or surgical biopsy. Images were analyzed by 2 radiologists with consensus and were correlated with histologic grades. RESULTS: Of the 76 lesions, 44 were classified as high--grade and 32 as non-high-grade DCIS. Fifty-seven lesions (75.0%) were identified on sonography, which revealed a mass in 30 cases, microcalcifications in 20, ductal changes in 4, and architectural distortion in 3. All cases with false-negative findings on sonography (n = 19) showed microcalcifications on mammography. On sonography, masses were more frequently found in non-high-grade (62.5%) than high-grade DCIS (22.7%; P < .01). No significant difference was seen in the sonographic features of masses between high-grade and non-high-grade DCIS. Microcalcifications were more common in high-grade (43.2%) than non-high-grade (3.1%) DCIS (P = .02). Most sonographically visible microcalcifications had associated findings such as ductal changes (n = 11), a mass (n = 7), or a hypoechoic area (n = 5). The detection rate of microcalcifications on sonography was higher in high-grade (62.9%) than non-high-grade DCIS (25.0%; P = .023). CONCLUSIONS: Microcalcifications with associated ductal changes (11 of 31 [35.5%]) were the most common sonographic findings in high-grade DCIS. An irregular hypoechoic mass with an indistinct and microlobulated margin (13 of 26 [50.0%]) was the most frequent finding in non-high-grade DCIS.

Breast cancer in elderly Korean women: clinicopathological and biological features.

BACKGROUND: With an aging society, Korean women ≥70 years of age are increasingly being diagnosed with breast cancer. OBJECTIVE: To investigate the clinicopathological and biological characteristics of breast cancer in elderly Korean women and compare them with breast cancer in elderly (≥70 years) women globally and in Korean women of all ages. METHODS: We retrospectively reviewed the clinicopathological and biological features of breast cancer in elderly Korean women (≥70 years; n = 87) who sought treatment during 2004-2014 from a single institution. These data were indirectly compared with data of Korean women of all ages (nationwide Korean Breast Cancer Registry) or elderly women globally (meta-analysis). RESULTS: Compared to elderly women with breast cancer globally, Korean elderly women had a more symptomatic presentation, lower ER expression, and overexpression or amplification of human epidermal growth factor receptor 2. Compared to Korean women of all ages with breast cancer, elderly Korean women presented with advanced tumor stages, larger tumor size, more lymph node involvement, and more luminal B and basal-like subtypes. CONCLUSIONS: Breast cancer had a more aggressive clinicopathological and biological characteristics in elderly Korean women than in Korean women of all ages or elderly women globally.

Relationship Between Breast Ultrasound Background Echotexture and Magnetic Resonance Imaging Background Parenchymal Enhancement and the Effect of Hormonal Status Thereon.

We studied the relationship between breast ultrasound background echotexture (BET) and magnetic resonance imaging (MRI) background parenchymal enhancement (BPE) and whether this relationship varied with hormonal status and amount of fibroglandular tissue (FGT) on MRI. Two hundred eighty-three Korean women (52.1 years; range = 27-79 years) with newly diagnosed primary breast cancer who underwent preoperative breast ultrasound and MRI were retrospectively studied. Background echotexture, BPE, and FGT were classified into 4 categories, and age, menopausal status, menstrual cycle regularity, and menstrual cycle stage at MRI were recorded. Background echotexture and BPE relationship was assessed overall, and in menopausal, FGT, menstrual cycle regularity, and menstrual cycle stage subgroups. Background echotexture and BPE correlated in women overall, and menopausal, FGT, and menstrual cycle subgroups and those in the first half of the cycle (all P < 0.001). Background echotexture reflects BPE, regardless of menopausal status, menstrual cycle regularity, and FGT and may be a biomarker of breast cancer risk.

Reflector Localization of Breast Lesions and Parameters Associated with Positive Surgical Margins in Women Undergoing Breast Conservation Surgery.

OBJECTIVE: To evaluate our experience with reflector localization of breast lesions and parameters influencing surgical margins in patients with a malignant diagnosis. METHODS: A retrospective institution review board-approved review of our institutional database was performed for breast lesions preoperatively localized from September 1, 2016, through December 31, 2017. Wire localizations were excluded. From electronic medical records and imaging, the following data was recorded: breast density, lesion type and size, reflector placement modality and number placed, reflector distance from lesion and skin, excision of lesion and reflector, tissue volume, margin status, and final pathology. Statistical analysis was performed with a Fisher's exact test, Mann-Whitney test, and logistic regression. P < 0.05 was significant. RESULTS: A total of 111 reflectors were deployed in the breasts of 103 women with 109 breast lesions. Ninety (81.1%) reflectors were placed under mammographic guidance and 21 (18.9%) under US. The lesions consisted of 68 (62.4%) masses, 17 (15.6%) calcifications, 2 (1.8%) architectural distortions, and 22 (20.2%) biopsy markers. Fourteen (21.2%) of 66 cases with a preoperative malignant diagnosis had a positive surgical margin. Final pathology, including 6 lesions upgraded to malignancy on excision, demonstrated 72 (66.0%) malignant, 22 (20.2%) high-risk, and 15 (13.8%) benign lesions. Univariate and multivariate analysis revealed no statistically significant parameters (lesion type or size, placement modality, reflector distance to skin or lesion, specimen radiography or pathology) were associated with a positive surgical margin. CONCLUSION: Reflector localization is an alternative to wire localization of breast lesions. There were no lesion-specific or technical parameters affecting positive surgical margins.

Increasing Size of Cholesterol Granuloma of the Breast in the Vicinity of a Previous Breast Biopsy: Imaging Features and Review of the Literature.

BACKGROUND Cholesterol granuloma is a benign condition that can occur in the breast following trauma, breast biopsy, or surgical procedures. Cholesterol granuloma can mimic breast cancer on imaging studies. This report is of a case of an enlarging breast mass due to a repeat needle biopsy in the vicinity of a previous biopsy that resulted in a cholesterol granuloma that appeared to increase in size on ultrasound imaging. The mammographic and high-resolution sonographic imaging features of cholesterol granuloma of the breast are described, with a review of the literature of published cases of cholesterol granuloma of the breast diagnosed on imaging. CASE REPORT A 52-year-old woman had undergone multiple rounds of breast ultrasound scans for multiple breast nodules. At six-month follow-up with a needle biopsy was performed that showed benign cystic change. At 18-months follow-up high-resolution sonographic imaging showed a circumscribed, oval, hypoechoic mass with a benign morphology in the vicinity of the biopsy site. The size of the hypoechoic nodule increased progressively, and histopathology confirmed the diagnosis of a benign cholesterol granuloma. CONCLUSIONS This case demonstrated that cholesterol granuloma of the breast can increase in size after repeats adjacent breast biopsy, and may retain benign morphological features on ultrasound imaging, despite increasing in size.

Sonographic Features of Flat Epithelial Atypia Manifesting as a Non-Mass-Like Lesion: A Case Report.

BACKGROUND The incidence of flat epithelial atypia of the breast has been increasing owing to the increasing use of ultrasonography (US) and US-guided core needle biopsy. However, reports describing the sonographic features of flat epithelial atypia are fewer than those on its mammographic features. CASE REPORT A 47-year-old female had a regular 6 month-interval follow-up US for multiple bilateral breast masses detected on US. A new focal non-mass-like lesion measuring 2 cm in maximum diameter was noted in the 10 o'clock direction of the right breast on the follow-up US. Mammography was not performed during the follow-up period. The patient had no breast symptoms and no family history of breast cancer or other pertinent medical history. US-guided 14-gauge core needle biopsy yielded a pathological diagnosis of flat epithelial atypia without upgrade to malignancy, and this was further confirmed after complete excision of the non-mass-like lesion. CONCLUSIONS Flat epithelial atypia can present as a focal non-mass-like lesion on US, which has not been reported previously.

Clinical and Imaging Features of a Ruptured Epidermal Inclusion Cyst in the Subareolar Area: A Case Report.

BACKGROUND Epidermal inclusion cysts rarely develop in the breast. The cysts that do develop within the breast typically present as cutaneous or subcutaneous cysts. They more rarely present in a subareolar location or in a ruptured state. Thus far, 5 cases of ruptured epidermal inclusion cysts in subareolar locations have been reported in the English literature. Furthermore, clinical presentation of nipple discharge is rare in epidermal inclusion cysts of the breast; only 4 such cases has been reported. CASE REPORT A 58-year-old female presented with a 1-month history of bloody discharge from her left nipple. Mammography showed focal asymmetry in the left subareolar region; sonography showed a left subareolar mass with irregular shape, indistinct margin, heterogeneous echogenicity, and posterior enhancement. The mass was surgically excised; a pathological diagnosis of ruptured epidermal inclusion cyst with foreign body reaction and abscess formation was established. In this case, the clinical presentation of bloody nipple discharge was peculiar; furthermore, mammographic and sonographic features were indistinguishable from breast malignancy or typical breast abscess. CONCLUSIONS A ruptured epidermal inclusion cyst can present in an unusual subareolar location, combined with bloody nipple discharge; importantly, this can radiologically resemble breast malignancy.