Papillotubular carcinoma with an invasive micropapillary carcinoma component of the breast,characterized by a rapid increase in size due to intra-tumoral hemorrhage: A case report

IntroductionRapidly enlarging mammary tumors, including invasive breast tumors, are clinically rare. Invasive micropapillary carcinoma (IMPC) of the breast is known to have aggressive behavior and poor clinical course compared to invasive ductal carcinoma.Case presentationAn 87-year-old woman presented with a rapidly enlarging tumor of the right breast over the course of 3 weeks. Ultrasonography and computed tomography of the chest revealed a giant tumor located on the right chest wall, with heterogeneous parenchymal components and several cystic lesions. Emergency mastectomy was performed because of rapid tumor enlargement complicated by hemorrhage. Histopathological diagnosis confirmed a papillotubular invasive ductal carcinoma with an IMPC component. Tumor cells were negative for estrogen and progesterone receptors, and the human epidermal growth factor receptor 2 score was 2+.DiscussionThere has been only one report of breast carcinoma with rapid enlargement caused by spontaneous intratumoral hemorrhage to date. IMPC is associated with a high incidence of axillary lymph node metastases, frequent local recurrence, and a poor clinical outcome. In the present case, the specific breast cancer type can be considered as potential factors responsible for hemorrhage induction within the tumor that further enhanced rapid tumor growth.ConclusionIMPC is a rare, clinically aggressive variant of invasive ductal carcinoma. Owing to its aggressive clinical behaviors, surgeons should readily recognize the morphology of IMPC.     

Presence of a micropapillary pattern in mucinous carcinomas of the breast and its impact on the clinical behavior

Infiltrating micropapillary carcinomas (IMPC) of breast are highly angioinvasive tumors with poor prognosis. This study is based on the observation that a similar micropapillary pattern is also observed in mucinous carcinomas of breast. About 102 mucinous carcinomas were evaluated for the presence and impact of this micropapillary pattern on the clinical behavior. Of these, 68 were mucinous carcinomas with a micropapillary pattern (MUMPC), 20 had MUMPC mixed with an infiltrating duct carcinoma component, two were solid variants of papillary carcinoma with mucin (SVPCMU), five had collision of the MUMPC and SVPCMU patterns and seven were mucinous carcinomas with signet ring cells (MUS). The factors negatively affecting overall survival (OAS) and disease-free survival (DFS) included the histological type of mucinous carcinoma, nodal metastases, an irregular tumor border, <50% mucin and an IMPC type of local recurrence or metastases. In the multivariate analysis, the histologic type of mucinous carcinoma and an irregular tumor border were most significant for OAS and DFS. Thus, 86% of mucinous carcinomas in this study were mucinous variants of the angioinvasive infiltrating micropapillary carcinomas. These tumors can produce IMPC type of metastases and thus should be treated aggressively.     

The presence of micropapillary features and retraction artifact in core needle biopsy material predicts lymph node metastasis in breast carcinoma

Retraction artifact around tumor cell nests is a characteristic feature of invasive micropapillary carcinoma (IMPC), a special type of breast cancer commonly associated with nodal metastasis. We have recently reported that the extent of retraction artifact in usual invasive ductal carcinomas (IDC) is also a strong predictor of nodal metastasis. We examined whether the presence and extent of micropapillary features and retraction artifact in core needle biopsy of breast cancers can predict nodal metastasis in a prospective series of 47 IMPC and 424 IDC. Micropapillary features were present on core needle biopsy in 28 of 47 IMPC cases. Nodal metastases were found in 21 of 28 and 14 of 19 IMPC cases with and without micropapillary features present on core needle biopsy, respectively. Lymph node metastasis was significantly associated with the presence of micropapillary features, but not with its extent within these tumors. The presence of extensive retraction artifact in core needle biopsy samples of IDC also showed a significant association with nodal metastasis. Our results indicate that the presence of micropapillary features or extensive retraction artifact on core needle biopsy of breast carcinoma can predict nodal metastasis. Our results support the notion that the characteristic clear spaces separating the tumor cells from the stroma in IMPC and IDC of the breast are not a random artifactual phenomenon simply resulting from tissue fixation and processing, but rather they are likely related to altered tumor-stromal interactions, which might have an important role in lymphatic tumor spread.     

Invasive Micropapillary Carcinoma of the Breast: A Clinicopathologic Study of 103 Cases of an Unusual and Highly Aggressive Variant of Breast Carcinoma

Invasive micropapillary carcinoma (IMPC) of the breast is an uncommon, highly aggressive breast cancer that may occur in pure and mixed forms. Our aim in this study is to investigate the relationship between clinical, histopathologic, and immunohistochemical features of pure and mixed IMPC cases diagnosed and treated at our institution. One hundred and three IMPC cases diagnosed at our institution over a period of 19 years have been selected. Clinical, histopathologic features, as well as hormone status and c‐erb‐B2 overexpression of tumors were re‐evaluated. Mann–Whitney U, chi‐squared, Kaplan–Meier, and Fisher's exact tests were used for statistical analyses. Results were considered to be significant at p < 0.05. Twenty cases (19.4%) were pure, and 83 cases (80.6%) were mixed IMPC. The most common nonmicropapillary invasive carcinoma component in mixed cases was invasive ductal carcinoma (IDC; 78.3%). Progesterone receptor was significantly less positive in pure IMPC cases (p = 0.031). There was no statistically significant difference between the two groups, in terms of mean age of the patients (53.0 versus 52.8), mean tumor size (26.6 mm versus 27.7 mm), presence of high‐grade tumor (p = 0.631), presence of sentinel lymph node (SN) metastasis (p = 1.000), axillary lymph node metastasis (p = 1.000), lymphatic invasion (p = 1.000) and blood vessel invasion (p = 0.475), c‐erbB‐2 overexpression of tumor cells (p = 0.616), distant metastasis (p = 0.549), or overall survival (p = 0.759). The local recurrence rate of the two groups was not statistically significant either (16.7% versus 4.3%). However, local recurrence was detected 12% more commonly (p = 0.100), and ~8 months earlier (p = 0.967) in pure IMPC cases, compared to mixed cases. In addition, presence of local recurrence was found to be statistically significantly associated with estrogen receptor (ER) status (p = 0.004), progesterone receptor (PR) status (p = 0.001), and c‐erb‐B2 overexpression (p = 0.016) in all patients. Overall survival rate was significantly associated with ER staining of the tumor (log‐rank = 0.028). Our findings suggest that hormone receptor negativity may explain the more aggressive behavior of pure IMPC compared to mixed cases. Besides, longer survival period of patients with ER positivity, and the relationship of hormone status and c‐erb‐B2 overexpression and local recurrence further support favorable prognostic value of hormone receptors in invasive breast cancer.     

Invasive micropapillary carcinoma of the breast in a male patient: Report of a case

INTRODUCTIONWe report a rare case of invasive micropapillary carcinoma in the male breast.PRESENTATION OF CASEA 63-year-old man was referred to our hospital for investigation of a left breast tumor, which could be palpated in the upper lateral quadrant of the left nipple-areola complex. The tumor invaded the areola skin. Ultrasonography showed a 14.8 × 15.0 × 12.4 mm low echoic mass, with an irregular lobulated border. Core needle biopsy indicated invasive ductal carcinoma, but the subtype could not be accurately determined. Mastectomy with axillary lymph node dissection was performed. Pathological examination indicated invasive micropapillary carcinoma, no lymph node metastasis, and a nuclear grade of 2. Immunohistochemical examination showed positive staining for estrogen and progesterone receptors, but negative staining for HER2. The Ki67 index was 5%. Tamoxifen was administered, and recurrence has not been noted for 1 year.DISCUSSIONWomen's IMPC generally shows a high HER2 positivity rate. However, HER2 positivity was noted in only 1 male patient with IMPC (14%) according to our literature review. Furthermore, in all cases of the mixed type that were reviewed, IMPC was associated with papillotubular carcinoma. These findings may be specific to IMPC in male patients.CONCLUSIONIMPC is associated with a high rate of lymph node metastasis or recurrence and advanced vessel invasion, aggressive adjuvant chemotherapy following surgical resection should be selected for patients with IMPC.     

The impact of molecular status on survival outcomes for invasive micropapillary carcinoma of the breast

Invasive micropapillary carcinoma (IMPC) is an uncommon variant of breast cancer. Previous studies demonstrated this subtype is often hormone receptor (HR)‐positive, resulting in survival outcomes similar to invasive ductal carcinoma. However, many of these studies were conducted prior to HER2 testing availability. We aim to determine the impact of molecular marker status (including HER2 status) on IMPC survival outcomes. The National Cancer Data Base (NCDB) was used to retrieve patients with biopsy‐proven IMPC from 2007 to 2012. Only patients with known HR and HER2 status were included. Cox multivariate regression was used to determine prognostic factors. In total, 865 patients were included; median follow‐up was 2.5 years. Overall, 651 patients (75.3%) had HR + HER2? disease, 128 (14.8%) had HR + HER2+ disease, 41 (4.7%) had HR‐HER2 + disease, and 45 (5.2%) had triple negative disease. Patients with triple negative disease were more likely to have poorly differentiated histology (66.7%), lymphovascular invasion (73.3%), stage 3 disease (37.8%), undergone mastectomy (68.9%), and positive surgical margins (15.6%). On Cox multivariate regression, those with triple negative disease had worse overall survival (hazard ratio [HR] 7.28, P < 0.001). Other adverse prognostic factors included African‐American descent (HR 2.24, P = 0.018), comorbidity score of 1 (HR 2.50, P = 0.011), comorbidity score ≥2 (HR 3.27, P = 0.06), and ≥3 positive lymph nodes (HR 3.23, P = 0.007). Similar to invasive ductal carcinoma, triple negative disease in IMPC results in worse survival outcomes. This is the largest and first study to characterize molecular status (including HER2 status) in patients with IMPC and its impact on survival outcomes.     

乳腺乳头状癌17例的诊断与治疗

目的 探讨乳腺乳头状癌的临床特征、病理和诊治.方法 回顾性分析温州医学院附属第一医院收治的17例乳腺乳头状癌的临床资料.结果 乳腺乳头状癌发病率占同期收治所有乳腺癌的0.64％.患者均可触及肿块.12例患者行乳腺癌改良根治术,2例行单纯乳房切除术,2例行保乳手术,1例行乳房单纯切除+前哨淋巴结活检术.术后15例行辅助化疗,其中5例另行放射治疗.术后随访时间1个月～8年,中位随访时间为32.5个月.1例发生骨转移于术后2年死亡,1例发生多器官转移于术后7年死亡.结论 乳腺乳头状癌患者的治疗及预后与其病理类型密切相关.对导管内乳头状癌的治疗宜选择低创伤的手段,对浸润性乳头状癌及浸润性微乳头状癌须按浸润性导管癌治疗原则处理.     

Immunophenotyping analysis in invasive micropapillary carcinoma of the breast: role of CD24 and CD44 isoforms expression

We analyzed immunohistochemically the expression of CD24 and spliced variants of CD44v5 and v9 in invasive micropapillary carcinoma (IMPC) of the breast that is a rather aggressive tumor characterized by alteration of cells adhesion molecules, early lymph node metastases and poor prognosis. We analyzed 31 high-grade IMPCs and compared their expression to 22 high grade (G3) invasive ductal carcinomas of the breast (IDCs). We found a higher expression of CD24 in high-grade IMPCs with a peculiar inverted apical localization, compared to IDCs, showing a strong cytoplasmic staining; normal breast tissue resulted completely negative. IMPCs showed reduced expression of CD44v5 and CD44v9 compared with IDCs, but without a statistical significant difference. This study demonstrated that IMPC represents a distinct entity of breast carcinoma with high expression of CD24 with a typical inverted apical membrane pattern and reduction of CD44 isoforms v5 and v9, compared to IDCs. These features could explain the high lymph-vascular invasion propensity and higher metastatic capability of these tumors and could be a useful tool for a future targeted therapy.     

Prognosis of invasive micropapillary carcinoma compared with invasive ductal carcinoma in breast: A meta-analysis of PSM studies

BackgroundInvasive micropapillary carcinoma (IMPC) is a rare histological subtype of breast cancer. The outcome of IMPC remains controversial; we conducted a meta-analysis of propensity score matching (PSM) studies to evaluate the prognostic difference between IMPC and invasive ductal carcinoma (IDC).MethodsWe searched PubMed, EMBASE and the Cochrane library for PSM studies comparing survival data between IMPC and IDC. The summarized odds ratios (ORs) and 95% confidence interval (95% CI) are calculated by STATA software utilizing fixed-effect or random-effect models, depending on the heterogeneity of the eligible studies.ResultsEight PSM studies including 2102 IMPC patients are included in the meta-analysis. Compared with IDC, IMPC has a similar overall survival (OS) (estimated OR = 0.87, 95% CI: 0.61–1.25), but a shorter relapse free survival (RFS) (estimated OR = 1.31, 95% CI: 1.06–1.61); the shorter RFS might owe to the significantly higher loco-regional recurrence rate of IMPC (estimated OR = 3.60, 95% CI: 1.99–6.52). Funnel plots and Egger’s tests are used to evaluate publication bias and the p value for OS and RFS are 0.036 and 0.564 respectively.ConclusionsOur results demonstrate that compared with IDC, IMPC exhibits a similar, even favorite OS, but a shorter RFS; and the shorter RFS might owe to the significantly higher loco-regional recurrence rate of IMPC. These results could contribute to the individualized therapy and follow-up strategies for IMPC patients.     

Isolated invasive ductal carcinoma of the nipple‐areolar complex: A rare occurrence yet to be reported in current literature

Invasive ductal carcinoma of the nipple‐areolar complex is exceedingly rare. Patients who present with bloody nipple discharge with or without the presence of Paget's disease constitute one‐third of all symptomatic in situ patients. Only rarely does an invasive cancer cause nipple discharge in the absence of a clinical mass. Even more obscure is the case of the invasive cancer involving solely the nipple‐areolar complex. Sir James Paget first described ‘an eczematous change in the skin of the nipple preceding an underlying mammary cancer’ in 1874, which is now known as Paget's disease, considered to be ductal carcinoma in situ of the nipple‐areolar region. There are two competing theories as to the pathogenesis of Paget's disease of the breast—one suggests that Pagetoid cells are keratinocytes that have undergone malignant transformation. According to this theory, Paget's disease of the breast represents an in situ carcinoma of the skin—and that overlying skin changes and underlying malignancy are discontinuous. The second theory suggests that cells migrate along basement membranes and enter the epidermis and dermis of the nipple‐areola complex. Pagetoid cells and underlying carcinomas demonstrate similar immunohistochemical staining patterns.     

乳腺浸润性导管癌的MRI诊断价值

目的探讨磁共振成像(MRI)对乳腺浸润性导管癌的临床应用价值。方法回顾性分析了2012年1月至2012年6月期间在四川大学华西医院放射科行MRI检查,且术后经病理学检查证实为乳腺浸润性导管癌的75例患者的术前MRI检查资料。结果形态学分型:团块型54例,结节型21例,囊实混合型0例。肿块形状:圆形3例,卵圆形9例,不规则形63例。边缘:不规则66例,规则9例;呈微小分叶状56例。肿块内有钙化者1例。有淋巴结转移者18例。MRI的T1WI呈低信号(65例)或等信号(10例),T2WI呈低信号(3例)或以稍高信号为主的混杂信号(72例),增强后大部分呈均匀强化(64例),部分呈不均匀强化(11例)。结论通过分析乳腺浸润性导管癌的MRI成像特征,可为临床诊断乳腺浸润性导管癌提供有力的影像学证据。     

Comparative Long‐term Study of a Large Series of Patients with Invasive Ductal Carcinoma and Invasive Lobular Carcinoma. Loco‐Regional Recurrence,Metastasis, and Survival

Our aim was to compare histologic and immunohistochemical features, surgical treatment and clinical course, including disease recurrence, distant metastases, and mortality between patients with invasive ductal carcinoma (IDC) or invasive lobular carcinoma (ILC). We included 1,745 patients operated for 1,789 breast tumors, with 1,639 IDC (1,600 patients) and 145 patients with ILC and 150 breast tumors. The median follow‐up was 76 months. ILC was significantly more likely to be associated with a favorable phenotype. Prevalence of contralateral breast cancer was slightly higher for ILC patients than for IDC patients (4.0% versus 3.2%; p = n.s). ILC was more likely multifocal, estrogen receptor positive, Human Epidermal Growth Factor Receptor‐2 (HER2) negative, and with lower proliferative index compared to IDC. Considering conservative surgery, ILC patients required more frequently re‐excision and/or mastectomy. Prevalence of stage IIB and III stages were significantly more frequent in ILC patients than in IDC patients (37.4% versus 25.3%, p = 0.006). Positive nodes were significantly more frequent in the ILC patients (44.6% versus 37.0%, p = 0.04). After adjustment for tumor size and nodal status, frequencies of recurrence/metastasis, disease‐free and specific survival were similar among patients with IDC and patients with ILC. In conclusion, women with ILC do not have worse clinical outcomes than their counterparts with IDC. Management decisions should be based on individual patient and tumor biologic characteristics rather than on lobular versus ductal histology.     

A Study of the Growth Patterns of Breast Carcinoma Using 3D Reconstruction: A Pilot Study

Lumpectomy with microscopically clear margins is a safe and effective approach for surgical management of breast carcinoma. Margins are positive for tumor in 18–50% of lumpectomies, as it is not possible to accurately determine the shape or microscopic borders of a tumor preoperatively or intraoperatively. We examined the 3D microanatomy and growth patterns of common breast carcinoma subtypes to provide guidance for lumpectomy surgery. Prospective consent was obtained for the use of excess tissue from patients undergoing lumpectomy or mastectomy for breast carcinoma. Tissue blocks from nine breast carcinomas were serially sectioned. Hematoxylin and eosin‐stained slides at 100 μm intervals were scanned using a Nanozoomer (Hamamatsu, Japan) microscopic‐resolution scanner. Three‐dimensional reconstructions of tumors were created from scanned images using Reconstruct, open‐access software. Breast carcinoma subtypes demonstrated characteristic growth patterns within breast tissue, which may have implications for lumpectomy surgery. Invasive ductal carcinomas showed a spherical shape, with a spiculated surface representing tumor cells infiltrating into surrounding parenchyma. Ductal carcinoma in situ appeared to spread along the duct system, creating dilated, tortuous, tumor‐filled ducts. The invasive lobular carcinomas examined had a haphazard, linear, infiltrative growth pattern, different from the shape seen in ductal carcinomas. Our preliminary work suggests that invasive ductal and invasive lobular carcinomas appear to have distinct growth patterns in three dimensions and ductal carcinoma in situ appears to grow in a linear fashion along the duct network. The microanatomy studies described have the potential to guide refinements in breast lumpectomy technique.     

Breast adenomyoepithelioma and adenomyoepithelioma with carcinoma (malignant adenomyoepithelioma) with associated breast malignancies: A case series emphasizing histologic,radiologic, and clinical correlation

The 2012 World Health Organization (WHO) classification of breast tumors distinguishes adenomyoepitheliomas (AMEs) as benign tumors composed of a biphasic proliferation of phenotypically variable myoepithelial cells around small epithelial lined spaces. Many AMEs have demonstrated benign behavior and are often cured with excision with negative margins, but some have exhibited malignant transformation of the myoepithelial cells, ductal epithelial cells, or both. When one of the components is histologically malignant, it is termed AME with carcinoma. Due to the rarity, the literature correlating imaging, histology, and clinical outcome is limited. A retrospective review was undertaken. A review of an institutional pathology database identified 14 cases with AME or malignant AME. Most AMEs had nonspecific imaging findings and were categorized as Bi-Rads 4. Histologic features of AME did not correlate with prior or concurrent breast malignancies or any radiographic features. Clinical follow up could be obtained for all but one case (mean follow up time = 75 months). 5 cases had no known treatment post-biopsy and 5 patients received mastectomy. No recurrences were noted. 3/13 cases of benign AME had associated breast malignancies including invasive ductal adenocarcinoma and ductal carcinoma in-situ. 1 case of malignant AME had a synchronous separate malignant phyllodes tumor. Given the unclear and unpredictable propensity for malignant transformation, conservative excision with negative margins currently seems appropriate.     

尿激酶型纤溶蛋白酶激活剂在浸润型乳腺癌中高表达的临床意义

目的:探讨尿激酶型纤溶蛋白酶激活剂(uPA)表达在乳腺浸润型导管癌中的表达及其与临床病理特征的关系。方法:采用免疫组织化学技术研究我院1990～2001年233例浸润型导管癌标本uPA、雌激素受体(ER)、孕激素受体(PR)及C-erbB-2的表达,探讨uPA表达与浸润型导管癌临床病理特征及与ER、PR、C-erbB-2表达的关系。结果:uPA表达与浸润型导管癌腋窝淋巴结转移、临床分期、C-erbB-2表达呈正相关(P<0.05);与ER、PR表达呈负相关(P<0.05)。uPA表达与病人年龄、肿瘤大小、组织学分级无显著相关。结论:uPA高表达对评价乳腺癌恶性程度和预测转移有重要作用,可作为评价乳腺癌预后的辅助指标,但需要进一步的随访研究。     

乳腺浸润性微乳头状癌与浸润性导管癌的临床病理对照研究

目的 探讨浸润性微乳头状癌(invasive micropapillary carcinoma,IMPC)和浸润性导管癌(invasive ductal carcinoma,IDC)的差异,分析乳腺浸润性微乳头状癌的临床病理及免疫组化特点.方法 回顾性分析2004年10月至2007年11月51例浸润性微乳头状癌患者临床病理资料.选取同期临床病理资料完整的102例浸润性导管癌患者做对照.结果 浸润性微乳头状癌和浸润性导管癌的乳头侵犯、淋巴管侵犯、淋巴结转移率、淋巴结转移水平、软组织侵犯、雌激素受体(estrogen receptor,ER)、孕激素受体(progestin receptor,PR)、三阴(ER,PR,HER2均为阴性)表达差异有统计学意义(P＜0.05).而闭经状态、发病侧别、淋巴结转移个数、人类表皮生长因子受体2(human epidermal growth factor receptor-2,HER2)表达及局部复发和远处器官转移差异无统计学意义.浸润性微乳头状癌组中位随访时间46个月(16～ 75个月),3年生存率和无病生存率分别为90.2％和84.3％.结论 浸润性微乳头状癌是一种呈现侵袭性生长方式的少见乳腺癌类型,具有嗜淋巴特性和易发结外软组织侵犯的特点.乳腺浸润性微乳头状癌高表达激素受体,三阴乳腺癌比例较少.     

Differences in prognostic factors and patterns of failure between invasive micropapillary carcinoma and invasive ductal carcinoma of the breast: Matched case–control study

PurposeWe designed this study to identify differences in prognostic factors and patterns of failure between invasive micropapillary carcinoma (IMPC) and invasive ductal carcinoma (IDC) in patients with breast cancer.Experimental designWe identified 72 cases of IMPC who were diagnosed between 1999 and 2007 at the Samsung Medical Center. These patients were matched with 144 controls who were diagnosed with IDC during the same period. Exact matches were made for age (±3 years), pathologic tumour and node stage, and treatment methods (surgery and radiation therapy).ResultsThe median follow-up period was 45 months (13–116) for IMPC and 50 months (16–122) for IDC. Lymphovascular invasion (LVI, p<0.0001), axillary lymph node extracapsular extension (ECE, p=0.001) and high nuclear grade (p=0.032) were more frequently detected in patients with IMPC. During the follow-up period, treatment failed in 15 IMPC patients (20.8%) and in 26 IDC patients (18.1%). Loco-regional recurrences developed in 11 IMPC patients (15.3%) and eight IDC patients (5.6%). Importantly, of 57 IMPC patients who had positive axillary nodes, seven patients (12.3%) had axilla and/or supraclavicular recurrence. Therefore, at 5 years, the loco-regional recurrence-free survival was 79.1% in the IMPC patients vs. 93.3% in the IDC patients (p=0.0024).ConclusionOur study showed that IMPC is associated with LVI, ECE, high nuclear grade, and a greater degree of loco-regional recurrence, especially in the axilla and supraclavicular areas. Therefore, axillary and supraclavicular radiation therapy should be considered in IMPC patients with axillary node metastasis.     

Male ductal carcinoma in situ presenting as bloody nipple discharge: a case report and literature review

Male breast carcinoma accounts for 1% of all diagnosed breast carcinoma. Pure ductal carcinoma in situ in men is extremely rare. Unfortunately, male breast cancer is often diagnosed at a late stage because of the minimal awareness of presenting symptoms by the patient and sometimes by the health care provider. Because of this late presentation, the overall prognosis is less favorable. This case is presented to emphasize the importance of recognizing bloody nipple discharge as a clinical sign of male ductal carcinoma in situ and an opportunity for early diagnosis.     

Breast Intracystic Papillary Carcinoma: An Update

Abstract:  Intracystic papillary carcinoma (IPC), a breast tumor mainly occuring in the elderly, has long been considered as a variant of ductal carcinoma in situ (DCIS). This is now debated since metastatic cases have been reported. In this study, surgical pieces of 20 IPCs were reassessed, and markers of myopepithelial layer (p63, CD10 and Smooth Muscle Actin) as well as estrogen receptors (ER) and progesterone receptors (PgR) and C-erb-B2 oncoprotein expression were systematically performed and quantified. In 10 cases, an associated unequivocal invasive component was found. In all 20 cases, no myoepithelial layer was found. Eighteen tumors were ER positive, 14 were PgR positive. Moreover, none of the tumors over-expressed C-erb-B2 oncoprotein. Therefore this study showed that in all cases of IPC there were microscopic features of invasive carcinoma despite good clinical prognostic indicators, and that precise characterization of tumors requires extensive paraffin embedding of surgical pieces.