Morphologic spectrum of estrogen receptor-negative breast carcinoma

CONTEXT: Estrogen receptor (ER)-negative breast carcinomas are a heterogeneous group of breast cancers that are generally thought to be aggressive. OBJECTIVE: To determine the morphologic and immunohistochemical spectrum of a consecutive series of ER-negative breast carcinomas, in an attempt to understand the pathogenesis and behavior of these lesions. DESIGN: Seventy-four consecutive cases of ER-negative invasive carcinomas were studied. Hematoxylin-eosin-stained sections were reviewed, and new sections were stained for c-erbB-2, p53, vimentin, and androgen and prolactin receptors. The findings were correlated with the axillary lymph node status as a measure of tumor aggressiveness. SETTING: The histopathology department of a tertiary referral teaching hospital. RESULTS: The tumors included 50 (68%) invasive ductal carcinomas, 21 (28%) medullary/atypical medullary carcinomas, and 1 each of invasive lobular, apocrine, and papillary carcinoma. Some of the invasive ductal cases had distinctive features that are described in this report. Maximum tumor diameter varied between 5 and 100 mm. Sixty tumors (81%) were grade 3, 13 (18%) were grade 2, and 1 (1%) was grade 1. Of the 60 cases in which the axillary node status was known, 34 (57%) had metastases, and 26 did not. Tumors associated with positive nodes were significantly larger than those associated with negative nodes (37.2 vs 17.8 mm, P <.001). A higher percentage of node-negative tumors were c-erbB-2 positive (42% vs 21%, P <.05). There were no differences between the 2 groups with regard to histologic type, tumor grade, or the expression of p53, vimentin, or androgen or prolactin receptors. CONCLUSIONS: Many ER-negative breast carcinomas have distinctive microscopic features. Not all ER-negative tumors are aggressive, as judged by the absence of lymph node metastases in 43% of cases in this series. Tumor size is the most important indicator for the likelihood of the presence of lymph node metastases. The wide range of tumor sizes encountered in this series suggests that the ER status of a tumor is determined early in its natural history and supports the existence of 2 separate pathways for the development of ER-negative and ER-positive breast carcinomas.     

Expression of E-cadherin and c-erbB-2/HER-2/neu oncoprotein in high-grade breast cancer

E-cadherin (E-CD) is an epithelial-specific cell adhesion molecule, whose expression is lost in invasive lobular (ILC) but not in invasive ductal carcinoma (IDC) of the breast. This cell adhesion system can be disrupted by tyrosine kinase c-erbB-2/HER-2/neu. We examined 106 cases of high-grade invasive breast cancer, including 91 IDCs, 12 ILCs and 3 pleomorphic lobular carcinomas (PLCs). We determined Nottingham histological grade and performed immunohistochemistry for estrogen and progesterone receptors (ER/PR), Ki-67, E-CD and c-erbB-2/HER-2/neu with subsequent fluorescence in situ hybridization. Amplification of c-erbB-2/HER-2/neu gene was observed in 55/91 (60.4%) of IDCs, 3/12 (25%) of ILCs and 1/3 (33.3%) of PLCs, and associated with positive axillary lymph nodes. E-CD expression was lost in 14/91 (15.4%) of IDCs, 10/12 (83.3%) of ILCs and 2/3 (66.7%) of PLCs. The loss of E-CD immunoreactivity in IDCs appeared to be associated with c-erbB-2/HER-2/neu gene amplification, negative ER/PR status and positive lymph nodes, whereas E-CD-positive ILCs tended to be HER-2/neu-positive. The biological significance of E-CD expression seems to be different in high-grade IDC and ILC. Oncogenic pathway mediated by c-erbB-2/HER-2/neu may affect the E-CD expression in most invasive ductal breast carcinomas in vivo.     

Breast carcinoma with micropapillary features: clinicopathologic study and long-term follow-up of 100 cases

To study the clinicopathologic characteristics and prognosis of invasive micropapillary carcinoma of breast (IMPC), 100 cases of invasive breast carcinoma with an IMPC component were reviewed. Compared with invasive ductal carcinoma, not otherwise specified, with similar histologic grades, carcinomas with IMPC were larger sized, had a higher lymph node metastasis rate with more nodes involved per case, and exhibited increased lymphovascular invasion. The presence of IMPC strongly correlated with the more aggressive behavior. No significant association was established between the proportion of the IMPC component and overall tumor size, histologic grade, lymph node metastasis rate, and distant metastasis, but a trend was noted. Long-term follow-up demonstrated a poorer 5-year and 10-year survival rate for patients with breast carcinoma containing an IMPC component. Breast carcinomas with micropapillary features are more aggressive tumors with a poorer prognosis. This specific structure should be carefully evaluated in the surgical pathology examination of breast carcinoma specimens.     

c-erbB-2 expression in different histological types of invasive breast carcinoma.

Sections of 149 breast carcinomas were examined for the over-expression of c-erbB-2 oncoprotein using the avidin-biotin immunoperoxidase technique and two different specific antibodies. These included the polyclonal antibody 21N and the monoclonal antibody 4D5. The tumours were divided into two main groups. The first included 75 cases of invasive ductal and classic invasive lobular carcinomas. The second group consisted of 74 cases with histological types known to have a good prognosis, including mucinous, alveolar variant of invasive lobular, medullary, tubular, cribriform and papillary carcinomas. Fifteen (20%) tumours of the first group were positive with the two antibodies. Fourteen of these were of the ductal type and one was a mixed invasive ductal and lobular carcinoma. Ten of the pure ductal cases had areas of comedo carcinoma. The intraductal elements in a further tumour were positively stained with 21N antibody only. None of the second group of tumours, which included histological types known to have good prognosis, stained with 4D5, although one mucinous carcinoma was positively stained with 21N. These findings suggest that in invasive breast carcinoma immunostaining for c-erbB-2 is mainly seen in a subgroup of ductal tumours, and that almost all other histological types, especially those associated with good prognosis, lack this expression.     

Breast carcinoma with predominant neuroendocrine differentiation

Neuroendocrine differentiation can be identified in a subset of human breast carcinomas, either as scattered cells or as a predominant neuroendocrine component. We report a case of an invasive breast carcinoma largely composed of neuroendocrine cells. Eight years after a left mammary lumpectomy for a pT2N1MO SBR III invasive ductal carcinoma, a 67-years-old woman presented with a metastastic neuroendocrine sternal mass. To establish a relationship between mammary carcinoma and bone metastasis, histological slides of both the breast tumor and axillary lymph nodes were reviewed, and an immunohistochemical study was performed. They showed that: a) the mammary carcinoma was composed of a majority of small and large neuroendocrine cells synaptophysin +, NCAM+, chromogranin - (80%), associated with 2 other differentiated non endocrine components, one of metaplastic squamous carcinoma (10%) and the other of ductal carcinoma (10%); b) 4 axillary lymph nodes were involved by the ductal component which contained few NCAM + but synaptophysin - cells; c) Estrogen and progesterone receptors and HER2 were negative in the breast tumor and the metastatic nodes. We discuss the histogenesis of composite mammary carcinomas with neuroendocrine differentiation, the outcome of each component and the prognostic relevance of such a diagnosis.     

Pleomorphic carcinoma of the breast: clinicopathological analysis of 26 cases of an unusual high-grade phenotype of ductal carcinoma

AIMS: Pleomorphic carcinoma is a poorly described entity whose phenotype is not well recognized as within the morphological spectrum of breast carcinoma. The purpose of this report is to describe the clinicopathological features of this tumour, and to promote its recognition as an unusual high-grade morphological variant of mammary ductal carcinoma. METHODS AND RESULTS: Histological slides of breast carcinomas (N = 64) coded between 1978 and 1995 as having pleomorphic or anaplastic features were reviewed. Pleomorphic carcinoma (N = 26) was diagnosed when > or = 50% of the tumour manifested a pleomorphic cell population (> sixfold variation in nuclear size). Tumours of lobular origin were excluded. All neoplasms occurred in women with a mean age of 53 years. Patients underwent biopsy and/or mastectomy (n = 24) or lumpectomy (n = 2). The tumours' mean size was 54 mm. All were high-grade neoplasms. The pleomorphic cell population comprised 50-100% of the tumour; 31% had a prominent spindled morphology. Fifty-eight per cent of the tumours were initially misclassified by referring pathologists as sarcomas or carcinomas, possibly metastatic. Adjacent DCIS or a transition to classic ductal carcinoma was present in 73%. Five (19%) patients were stage I and three (12%) had stage IV disease. Axillary dissections yielded > or = 3 (mean 7.2) positive lymph nodes in 52%. Most (68%) tumours were aneuploid; a high S-phase (> 10%) was present in 63%. All neoplasms were ER negative and all but one were PR negative. p53 expression was present in 71%; none expressed bcl-2. c-erbB-2 was detected in four (19%) node-positive and in 0 (0%) node-negative cases (P = 0.01). Of 16 patients with follow-up, 6 (38%) were disease-free (mean, 74 months), four (25%) alive with disease (mean, 33 months) and six (38%) dead of disease at a mean of 22 months. CONCLUSIONS: Pleomorphic carcinoma is a prognostically unfavourable lesion and represents the extreme end of the morphological spectrum of grade III infiltrating ductal carcinoma.     

E-selectin and Sialyl Lewis X expression is associated with lymph node metastasis of invasive micropapillary carcinoma of the breast

To investigate the possible roles of E-selectin and its ligand, Sialyl Lewis X, in lymph node metastasis of invasive micropapillary carcinoma of the breast, 100 cases of invasive micropapillary carcinoma and 97 cases of invasive ductal carcinoma were analyzed immunohistochemically for the expression of E-selectin and Sialyl Lewis X, along with CD34, to measure the microvessel density of invasive micropapillary carcinoma. We found that the number of E-selectin-positive vessels was greater in invasive micropapillary carcinoma than in invasive ductal carcinoma, and it was significantly correlated with the histological grade, the number of positive lymph nodes, and the microvessel density of invasive micropapillary carcinoma. The Sialyl Lewis X expression of invasive micropapillary carcinoma was higher than that of invasive ductal carcinoma, which was also associated with lymph node metastasis. In invasive micropapillary carcinoma, the Sialyl Lewis X expression was predominantly in the stroma-facing surface of the cell clusters and the adjacent stroma, while in invasive ductal carcinoma it was largely intracytoplasmic or intercellular. These findings suggested that E-selectin and Sialyl Lewis X might play an important role in lymph node metastasis in invasive micropapillary carcinoma. The expression pattern of Sialyl Lewis X in invasive micropapillary carcinoma suggested that the reversal of cell polarity of invasive micropapillary carcinoma might be as an important factor for the morphogenesis and possibly the pathogenesis, especially their higher rates of lymph node metastasis.     

Invasive micropapillary carcinoma of the breast: eighty cases of an underrecognized entity.

Eighty cases of infiltrating duct carcinoma of the breast with a pure or partial micropapillary component are reported. The cases were analyzed using various parameters, including age at presentation, tumor size, tumor grade, presence of lymphatic invasion, and axillary lymph node status. The patients' age at presentation ranged from 36 to 92 years (mean, 58.8 years). Tumor size ranged from 0.1 to 10 cm (mean, 2.0 cm); 67.5% (54 of 80) were poorly differentiated, and 32.5% (26 of 80) were moderately differentiated; 62.5% (50 of 80) of the cases had lymphatic invasion; 72.3% (47 of 65) of cases with axillary dissections had positive lymph nodes; and 25% (20 of 80) of the tumors were < or = 1.0 cm and 7.5% (6 of 80) were < or = 0.5 cm. The characteristics of these small tumors with an invasive micropapillary component have not previously been reported. Despite their minute size, these small micropapillary carcinomas seem to show the same proclivity for lymphatic spread and nodal dissemination as larger tumors with this unique histologic pattern.     

c-erbB-2 overexpression and histological type of in situ and invasive breast carcinoma.

AIMS: To assess c-erbB-2 immunostaining in relation to morphological type of in situ and invasive breast carcinoma. METHODS: Formalin fixed, wax embedded archival tissue was used. Invasive carcinomas comprised 50 infiltrating ductal (NOS); seven medullary, 10 tubular, 15 mucinous and 24 classic invasive lobular. In situ carcinomas comprised 48 ductal (DCIS) and 10 cases of lobular (LCIS). The antibodies used were pAB1 (polyclonal) which stains cell lines that over express the c-erbB-2 oncogene, and ICR 12 (monoclonal) which stains sections of breast carcinoma known to show c-erbB-2 amplification. RESULTS: Immunostaining consistent with c-erbB-2 overexpression was found in 10 out of 50 cases of infiltrating ductal carcinoma (NOS), one of 24 infiltrating lobular carcinomas and one of seven medullary carcinomas only. Seventy per cent of ICR 12 positive cases of infiltrating ductal carcinoma also had extratumoral DCIS. Forty six per cent of pure DCIS lesions also showed strong membrane staining for c-erbB-2 protein, confined to large cell types. CONCLUSIONS: Immunostaining for c-erb B-2 oncoprotein occurs mainly in large cell DCIS and infiltrating ductal carcinoma NOS, especially those with an extratumoral DCIS component. There is a low incidence in other types of breast cancer, including those associated with a better prognosis. Different biological mechanisms may be responsible for histologically distinct types of breast carcinoma.     

The expression of Wilms' tumour-1 and Ca125 in invasive micropapillary carcinoma of the breast

AIM: Metastases from ovarian serous papillary carcinoma to the breast and primary invasive micropapillary carcinoma of the breast are histologically similar. The distinction is clinically important to ensure appropriate management. Wilms' tumour-1 (WT1) and Ca125 are frequently expressed in serous papillary carcinomas, and uncommonly in unselected mammary carcinomas. One previous study found Ca125 expression in 69% of invasive micropapillary carcinomas. The aim was to assess the frequency of expression of WT1 and Ca125 in invasive micropapillary carcinoma. METHODS AND RESULTS: Twenty-five of 34 invasive micropapillary carcinomas showed no nuclear expression of WT1. The remaining nine tumours showed weak to moderate immunoreactivity in 1-10% of nuclei. Six of these nine tumours also contained ductal carcinoma in situ, which expressed WT1 in five of the six. Membranous or cytoplasmic expression of Ca125 was found in seven tumours. CONCLUSION: Nuclear WT1 expression is present in a minority of invasive micropapillary carcinomas and, when present, expression is focal. The frequency of expression of Ca125 was similar to the results in unselected mammary carcinoma. Thus, these markers are useful members of the immunohistochemical panel for the distinction of mammary invasive micropapillary carcinoma from ovarian serous papillary carcinoma.     

Expression of EGFR family and steroid hormone receptors in ductal carcinoma in situ of the breast.

The expression of EGFR family and steroid hormone receptors was examined in a series of 40 cases of pure ductal carcinoma in situ (DCIS) of the breast by immunohistochemical staining of paraffin-embedded sections. Hematoxylin and eosin-stained sections were used to classify the tumors according to the published criteria by Holland et al. (Holland R, Peterse JL, Millis RR, et al. Semin Diagn Pathol. 1994;1 1:167-180). Of the tumors 48% were immunoreactive for EGFR, 63% for c-erbB-2, 78% for c-erbB-3, 95% for c-erbB-4, 88% for estrogen receptor (ER) and 80% for progesterone receptor (PR). Statistically significant association between histological grade (differentiation) and c-erbB-2 protein expression was seen (p <.001). In addition, expression of c-erbB-4 protein was associated with c-erbB-2 (p=.004), c-erbB-3 (p=.058), ER (p=.002) and PR (p=.004). It is concluded that c-erbB-2 expression in DCIS is associated with high-grade pathological features, and a higher c-erbB-2 expression is seen in DCIS than in invasive breast carcinomas. A possible association between extensive expression of c-erbB-4 and steroid hormone receptors in proliferative and premalignant breast epithelial cells and the c-erbB-2 expression in DCIS and invasive breast carcinomas is discussed.     

Tubular carcinoma of the breast and associated intra-epithelial lesions: a comparative study with invasive low-grade ductal carcinomas

Ductal intra-epithelial lesions of the breast are associated with invasive neoplasms and comprise a large spectrum of histological patterns. We have examined 23 cases of pure tubular carcinomas (TCs) of the breast and 53 cases of invasive ductal low-grade carcinomas to determine the relationship and distribution of intra-epithelial lesions, mainly of ductal in situ carcinoma type, but including also lobular intra-epithelial neoplasia (LIN) in both entities. Eleven cases of TC showed flat epithelial atypia (FEA) (47.8%), and, in 14 and 6 cases, micropapillary and cribriform low-grade ductal carcinoma in situ (DCIS) were present (60.7 and 26.1%, respectively). On the opposite, in ductal grade I invasive carcinomas, the most frequent architectural pattern was low-grade DCIS growing in arcades in 26 cases (49%). While absent in TCs, low-grade DCIS of solid type was found in five (9.4%) cases of ductal invasive carcinomas, where FEA were present in seven (13.2%) cases. LIN lesions were present in four (17.4%) cases of TC, whereas they represented 7.5%, as reported by Carstens et al. (Am J Clin Pathol 58:231–238, 1972), of cases of low-grade carcinomas. These results suggest that invasive pure TC and low-grade ductal carcinomas of the breast are different lesions, and support the fact that TC, of low histopathological grade, is a particular distinct tumoural entity.     

Metastatic breast carcinoma with appearance resembling micropapillary ductal carcinoma in situ.

AIM--To investigate tumour in an axillary lymph node resembling micropapillary ductal carcinoma in situ. METHODS--Sections of tumour in the breast and axillary lymph node were stained with haematoxylin and eosin, and immunohistochemically with antibodies to basement membrane and myoepithelial cells. RESULTS--Tumour in both the breast and axillary lymph node contained areas resembling micropapillary ductal carcinoma in situ. Surrounding these islands, there was a band of eosinophilic material resembling basement membrane and spindle cells that in places appeared to lie outside the basement membrane. Micropapillary tumour at both sites showed weak and discontinuous staining for collagen IV and laminin. The spindle cells stained for alpha-smooth muscle actin, but not for S100. By contrast, immunohistochemistry showed complete rings of basement membrane and myoepithelial cells around definite ductal carcinoma in situ and normal breast lobules and ducts. CONCLUSIONS--Invasive primary and metastatic carcinoma of the breast can have a growth pattern resembling micropapillary ductal carcinoma in situ.     

Invasive mucinous carcinoma arising within breast fibroadenoma

Malignant neoplasms arising in the epithelial component of breast fibroadenomas are rare. The most frequent types are lobular and ductal intra-epithelial carcinomas, with a minority of infiltrating carcinoma. We report a case of 36-year-old patient with invasive mucinous carcinoma (30 x 30 mm) arising in a complex breast fibroadenoma (130 x 60 x 30 mm). The patient underwent mastectomy with dissection of the axillary lymph nodes, which were free of tumour. The patient is alive without disease five years later. To the best of our knowledge, this is the first report of an invasive mucinous carcinoma arising within breast fibroadenoma. Our case provides information about the clinicopathologic characteristic of this unusual tumour.     

Expression of c-erbB-2 in in situ and in adjacent invasive ductal adenocarcinomas of the female breast.

Several lines of evidence have demonstrated that expression of the c-erbB-2 gene product contributes to the malignant phenotype. We and others have determined that c-erbB-2 is substantially expressed in most ductal in situ carcinomas of the comedo type, but not in other patterns of ductal carcinoma in situ or in atypical ductal hyperplasia of the breast. In the present investigation, by immunohistochemistry we inquired whether invasive ductal adenocarcinomas retained the c-erbB-2 expression status of the in situ carcinomas from which they derived. Of twelve specimens containing both cribriform/micropapillary in situ and derivative invasive adenocarcinomas in the same section, all tumor cells were negative for c-erbB-2 expression. In thirteen in situ carcinomas of the comedo type, with identifiable invasive components, ten had definite c-erbB-2 expression, and in every case there was comparable c-erbB-2 protein staining of in situ and invasive components; in three of these ten cases the staining in the in situ component tended to be more intense. These findings imply that a significant proportion of invasive mammary adenocarcinomas expressing c-erbB-2 protein is derived from ductal in situ carcinomas of the comedo type.     

Fine-needle aspiration biopsy of invasive micropapillary carcinoma of the breast: a report of five cases

Invasive micropapillary carcinoma of the breast is an uncommon variant of infiltrating ductal carcinoma. Observing its distinctive cytologic appearance and aggressive behavior is important for early diagnosis by fine-needle aspiration cytology (FNAC). There are only a few reported cases in the literature. Five women presented with breast masses. FNAC showed malignant epithelial tumors, and mastectomy materials showed invasive micropapillary carcinoma for all of them. Three patients had axillary lymph node metastases. Invasive micropapillary carcinoma, with its angulated papillary clusters lacking a fibrovascular core, and irregular crowded nuclei, has a distinctive cytologic appearance which correlates with its histological features. A differential diagnosis from other primary or metastatic papillary lesions of the breast may be possible using immunohistochemistry and some cytologic features. The limited experience with invasive micropapillary carcinoma should not discourage others from undertaking further studies.     

乳腺癌中E-cadherin的表达及其临床病理意义

目的 探讨上皮钙黏附表（E-cadherin，E-cad）与乳腺癌临床病理和生物学行为的关系。方法 用免疫组化S-P法检测乳腺浸润性导管癌和浸润性小叶癌中E-cad的表达情况及其与淋巴结转移，ER-PR表达水平的相关性。结果 乳腺浸润性导管癌E-cad表达高于浸润性小叶瘤，有淋巴结转移者E-cad表达低于无转移者，E-cad高表达的乳腺浸润性导管癌及浸润性小肾癌中均与ER-PR表达水平成正相关。结论 E-cad中作为乳腺癌分类、转移潜能和预后判断的参考指标。     

乳腺典型髓样癌与不典型髓样癌临床病理分析

目的探讨乳腺典型与不典型髓样癌的临床病理特征和生物学行为差异。方法对乳腺典型髓样癌及不典型髓样癌各20例临床病理资料进行分析,并采用S-P法检测nm23、E-cad、p53、ER、PR、c—erbB—2、CD45RO和CD20的表达。结果典型髓样癌组,癌细胞合体性结构〉75％,无腺管结构,间质见弥漫性淋巴细胞浸润;不典型髓样癌组,可见腺管结构,间质无或少量淋巴细胞浸润。免疫组化检测典型髓样癌nm23、E—cad阳性表达均高于不典型髓样癌。典型组随访12～84月（平均37个月）,均无腋下淋巴结转移,均健在;不典型组随访9～84月（平均29．5个月）,腋下淋巴结转移4／20例,其中4例分别于术后1—3年内死亡。结论①要严格掌握乳腺典型髓样癌与不典型髓样癌的病理诊断标准。②不典型髓样癌不完全等同“乳腺浸润性导管癌伴髓样特点。”③乳腺典型与不典型髓样癌的预后不同,前者明显优于后者。     

Incomplete inside-out growth pattern in invasive breast carcinoma: association with lymph vessel invasion and recurrence-free survival

Invasive micropapillary carcinoma (IMPC) is a rare subtype of epithelial tumor of the breast listed in the 2003 World Health Organization histologic classification of tumors of the breast. It is characterized by inside-out micropapillary morphology, frequent lymph vessel invasion (LVI), and lymph node metastasis; however, its etiology remains unknown. This study investigated the incomplete inside-out growth pattern (IGP) in invasive ductal carcinoma, not otherwise specified (NOS), and examined the association between incomplete IGP and clinicopathologic features, including the presence of intratumoral lymph vessels (ILV), LVI, nodal metastasis, and prognosis. Tumor tissues from 166 invasive duct carcinomas NOS and 10 IMPCs were immunostained using an anti-epithelial membrane antigen antibody to detect IGP and with D2-40 antibody to determine the presence of ILV and LVI. Incomplete IGP was detected focally in 88 (53%) of 166 invasive duct carcinomas NOS. Transition areas between IMPC and invasive duct carcinoma NOS also showed prominent incomplete IGP in 9 (90%) of 10 IMPCs. Incomplete IGP in invasive duct carcinomas NOS was associated with larger tumor size, higher frequencies of ILV, LVI, nodal metastasis, and poorer recurrence-free survival by univariate analysis. Incomplete IGP, ILV, and tumor size independently affected LVI by multivariate analysis. These findings indicate that incomplete IGP of tumor cell clusters is not uncommon and is a useful tool for predicting LVI in invasive duct carcinoma NOS of the breast.     

Metaplastic variant of invasive micropapillary breast carcinoma: a unique triple negative phenotype

Invasive micropapillary carcinomas (IMC) and metaplastic breast carcinoma (MBC) have different clinicopathologic features. This study reports an unusual case of multifocal grade III IMC associated with MBC component in a 35-year-old woman. MBC was vimentin positive, pancytokeratin negative, and showed focal p63 positivity. Immunostains for estrogen and progesterone receptor, and fluorescence in situ hybridization for Her2/neu amplification were negative. All the left axillary lymph nodes dissected were positive for metastatic carcinoma with ductal and IMC patterns, but without metaplastic component. Postmastectomy computed tomography and magnetic resonance imaging scans showed metastases to lungs, liver, brain, and vertebrae. The biologic behavior of tumor was in accordance with histology, so that the nodal and distant metastases were testament to the underlying inherently aggressive IMC, whereas large tumor size and triple negativity reflected the features of MBC. To the best of the authors' knowledge, this is the first report of a metaplastic variant of invasive micropapillary breast carcinoma with triple negative phenotype.