E-cadherin immunohistochemical analysis of histiocytoid carcinoma of the breast

Histiocytoid carcinoma is a rare type of invasive breast carcinoma. It has been considered to be a variant of lobular carcinoma, a variant of apocrine ductal carcinoma, and an apocrine variant of lobular carcinoma and to resemble lipid-rich carcinoma. In attempts to elucidate its histogenesis, investigators have used mucin and oil red O histochemical analysis and GCDFP-15 immunostaining. E-cadherin is a relatively recent addition to the armamentarium of immunohistochemical markers used for cell differentiation and is a member of a family of transmembrane glycoproteins that has been shown to have a strong correlation with the histologic phenotypes of breast carcinoma. Most ductal carcinomas show diffuse membrane expression of E-cadherin, and lobular carcinomas are characterized by complete lack of membrane staining of E-cadherin. The object of this study was to use E-cadherin immunohistochemical analysis to help clarify the histogenesis of histiocytoid carcinoma. Fourteen cases containing the diagnosis of histiocytoid carcinoma of the breast were identified at M. D. Anderson Cancer Center (Houston, TX) from 1988 to 2001. All cases were rereviewed, histologic features were evaluated, and immunohistochemical staining with E-cadherin and GCDFP-15 was performed. Clinical information was extracted from the patients' medical records. Eleven cases met published histologic criteria for histiocytoid carcinoma. The remaining three cases were apocrine carcinoma. The pattern of tumor infiltration was solid, without secondary lumen formation in all cases of histiocytoid carcinoma. Lobular carcinoma in situ was identified in eight cases, but was absent in three. There was no E-cadherin immunohistochemical staining in eight of the 11 cases of histiocytoid carcinoma (72.7%). GCDFP-15 was immunoreactive in all 10 cases of histiocytoid carcinoma where it was performed. Follow-up data was available for nine of the 11 cases of histiocytoid carcinoma: six patients were alive with disease at 1.5 to 48 months, one patient had died of disease at 60 months, and two patients had no evidence of disease at 32 and 45 months. We conclude that histiocytoid carcinoma has an immunophenotypical profile consistent with both ductal and lobular differentiation. Moreover, the lack of consistent morphologic features, a specific clinical profile, and a distinct immunohistochemical pattern lead us to hypothesize that histiocytoid carcinoma is not a special type of breast cancer.     

Histiocytoid breast carcinoma: an enigmatic lobular entity

Histiocytoid breast carcinoma is an uncommon entity that is mostly regarded as a variant of lobular carcinoma. Its occurrence with apocrine lobular carcinoma in situ and consistent expression of gross cystic disease fluid protein 15 suggest apocrine differentiation. Its recognition is often challenging, particularly when histiocytoid tumour cells occur in a metastatic site before the primary diagnosis of breast carcinoma, or in limited core biopsy or cytology material. In the breast, its bland histological appearances can lead to a benign diagnosis. Clues to the correct conclusion include finding tumour cells with more cytological atypia, the presence of cytoplasmic vacuoles and secretions, coexistence with more traditional invasive lobular carcinoma patterns and/or lobular neoplasia, and the use of immuohistochemistry to confirm their epithelial nature. Close clinicoradiological correlation and awareness of histological mimics are needed to achieve an accurate diagnosis of this enigmatic condition that should be appropriately subsumed within the invasive lobular histological subtype.     

Pleomorphic lobular carcinoma of the breast: an aggressive tumor showing apocrine differentiation.

Pleomorphic lobular carcinoma of the breast is a recently recognized subtype of invasive lobular carcinoma (ILC). Cytologic features are pleomorphic to a degree that contrasts with the cytologic uniformity of classic ILC. It is this feature that simultaneously gives its name to the tumor and highlights the difficulty of identifying it correctly and distinguishing it from ductal carcinoma. In our series of 10 cases, six tumors also contained lobular carcinoma in situ. Nodal metastases were typically sinusoidal. All tumors showed the dissociated, linear, and single file pattern of classic ILC, together with a targetoid distribution. Intracytoplasmic lumina were present in 50% of the tumors. An eosinophilic, slightly granular cytoplasm suggests the possibility of apocrine differentiation, a suggestion derived also from the frequent presence of foamy cells, a cell type previously identified in histiocytoid lobular carcinoma and shown to have apocrine features. The GCDFP-15 apocrine marker was positive in all 10 tumors, while all control ILCs were negative, confirming the presence of apocrine differentiation in pleomorphic lobular carcinoma. Six of 10 patients died within 42 months of diagnosis. Three other patients developed recurrence or distant metastases at short intervals. Pleomorphic lobular carcinoma is a very aggressive tumor. This behavior is perhaps predictable on the basis of tumor size at presentation and the frequency of nodal metastases. Since grading of lobular carcinoma is difficult, recognition of the pleomorphic subtype is useful in identifying a lethal variant.     

Histiocytoid breast carcinoma: Histological, immunohistochemical, ultrastructural, cytological and clinicopathological studies

Histiocytoid breast carcinoma (HBC) is a rare variant of breast carcinoma and often causes a diagnostic dilemma because of its histological similarities to some types of breast cancer and benign lesions. To elucidate the incidence of HBC and its biological properties, histological specimens from 1010 breast cancer patients treated at Yokohama Minami Kyosai Hospital between 1972 and 1996 were reviewed. Three cases of pure HBC and three cases of combined HBC (two with pleomorphlc lobular carcinoma and one with apocrine ductal carcinoma) were found, yielding an Incidence of 0.3% for each. Two of the three pure HBC cases contained foci of in situ lobular carcinoma. Targetoid and Indian file invasive patterns, the features characteristic of lobular carcinoma, were present in all three pure HBC cases and in two of the three combined HBC with pleomorphic lobular carcinoma. These results, together with those of previous studies, suggested that the majority of HBC are of lobular origin, although the apocrine ductai origin is also possible in a small number of HBC. Diastase-resistant periodic add-Schiff-positive granules and granular immunoreactivities for gross cystic disease fluid protein-15 (GCDFP-15) were characteristic of the histiocytoid tumor cells in both the pure and combined HBC, suggesting the apocrine differentiation of tumor cells. All three pure HBC cases were in stage 1 and were free of the disease for up to 5 years and 1 month after the lumpectomy. Thus, the prognosis of HBC appears to be dependent on the stage of the disease and may not always be poor, as indicated by the original report mentioning a preferential eyelid metastasis.     

Expression of aberrant mucins in lobular carcinoma with histiocytoid feature of the breast

The clinicopathological profiles of histiocytoid carcinoma of the breast have not been well examined because of their rarity and heterogenous groups of ductal and lobular origin. A large foamy or granular cytoplasm of histiocytoid carcinoma was characterized by abundant mucin, but the properties of mucin in histiocytoid carcinoma have also not been well investigated. We selected eight cases of histiocytoid features of invasive lobular carcinoma (HLC) and compared with 14 age- and tumor size-matched cases of classical invasive lobular carcinoma (CLC). Mucin profiles were significantly different between the two groups: a fair number of HLC cases were immunopositive for MUC2 and MUC5AC (75 and 50%, respectively); in contrast, almost all CLC cases showed both as negative. Both groups were immunopositive for MUC1 and negative for MUC4 and MUC6. The prognosis of HLC was significantly worse than CLC; HLC showed shorter disease-free time than CLC (p=0.0262). In particular, HLC with MUC2 and MUC5AC expressions showed significantly shorter disease-free time and survival time than lobular carcinoma without the expressions of MUC2 and MUC5AC (p=0.0055 and p=0.0060, respectively). Therefore, the expression of 'non-mammary mucins', such as MUC2 and MUC5AC in HLC, is characteristic and indicates the more malignant transformation of tumor cells and poorer prognosis.     

Infiltrating lobular carcinoma of the breast with histiocytoid features: three cases

Histiocytoid carcinoma of the breast, a cellular variant of invasive breast cancer, is mainly found among infiltrating lobular carcinomas (ILC). It can be easily confused with benign conditions or other mammary tumors also composed of cells with a pink granular to foamy cytoplasm and an eccentric nucleus. We report 3 cases of histiocytoid ILC. Our aim is to discuss recent immunocytochemical data that could suggest a special type of apocrine differentiation of tumor cells, including a diffuse immunoreactivity for GCDFP-15 (Gross Cystic Disease Fluid Protein 15) and a predominant expression of androgen receptor, and to describe the features useful for the differential diagnosis.     

Carcinoma in situ involving sclerosing adenosis: a mimic of invasive breast carcinoma

The distinction between invasive and in situ carcinoma of the breast is important with regard to the treatment and prognosis of the patient. When carcinoma in situ involves breast tissue in which the normal architecture is altered by pre-existing sclerosing adenosis, the resulting histological picture may closely mimic an invasive carcinoma. We record the histopathological features in 13 cases where there was difficulty in identifying the presence or extent of invasive carcinoma. The most useful clue was attention to the low power appearances of distorted lobular units in the areas of malignancy and comparison with surrounding breast tissue which usually showed recognizable sclerosing adenosis. The use of immunohistochemical stains for myoepithelium (α-actin and S-100 protein) and for basement membrane (collagen type IV and laminin) proved to be of considerable value in identifying the preservation of these features around glandular structures in areas of sclerosing adenosis containing in situ carcinoma.     

Invasive pleomorphic lobular carcinoma, negative for ER, PR and Her/2neu--a case report

Pleomorphic variant of lobular carcinoma is a recently described variant of invasive lobular carcinoma. It is reported to be positive for estrogen receptors and progesterone receptors and over express Her2/neu in most cases. We present here a case of invasive variant of pleomorphic lobular carcinoma with coexisting classic and pleomorphic variants of lobular carcinoma in situ along with focal ductal carcinoma in situ. The immunohistochemical results on hormone receptors and high molecular weight cytokeratins in all the above components of the tumor are presented. The invasive tumor was negative for estrogen receptors, progesterone receptors and Her2/neu. Most foci of lobular carcinoma in situ showed morphogenic heterogeneity and a corresponding heterogeneous staining for hormone receptors. The high molecular weight cytokeratins (CK5/6 and CK 903) were non contributory in establishing diagnosis.     

Intralobular growth of myoepithelial cell carcinoma of the breast

Two cases of intralobular carcinoma of the breast showing myoepithelial cell differentiation are reported. One was an in situ lesion localized within a fibroadenoma; the second was predominantly in situ, but areas of invasion were present. The neoplastic cells had round to ovoid nuclei and were polygonal to spindle in shape displaying glycogen rich clear cytoplasm. Alphasmooth muscle actin was present in the cytoplasm of the neoplastic cells in both cases. In one case the same cells displayed cytoplasmic microfilaments at electron microscopic level. Intralobular growth of neoplastic myoepithelial cells has never been described in the literature, and this line of differentiation has to be added to the endocrine and apocrine features occasionally observed in in situ lobular carcinomas of the breast.     

Transitional cell carcinoma of the bladder mimicking lobular carcinoma of the breast: a discohesive variant of urothelial carcinoma

AIMS: To describe a series of 10 cases of transitional cell carcinoma which show morphological features which mimic lobular carcinoma of the breast and diffuse carcinoma of the stomach. METHODS AND RESULTS: Ten cases were identified from the files at Southampton University Hospitals NHS Trust and from the authors' consultation files. Immunostains were performed and clinical information was obtained. Eight of the patients were male and two female. Ages ranged from 52 to 77 years at presentation. All of the tumours showed areas where the tumour was composed of uniform cells with a discohesive single-cell, diffusely invasive growth pattern. In areas the tumour cells were arranged in linear single-cell files and in separate areas solid sheets of discohesive cells. In all of the cases some tumour cells showed prominent intracytoplasmic vacuoles. In addition to this pattern, four cases showed typical transitional cell carcinoma or carcinoma in situ. The majority of the tumours expressed cytokeratin 20 but not oestrogen receptors. CONCLUSION: This study highlights a pattern of diffusely invasive transitional cell carcinoma not previously described and one which is important to recognize in order to avoid misdiagnosis of metastatic lobular carcinoma of the breast, especially in small biopsies.     

Pleomorphic lobular carcinoma in pleural fluid: diagnostic pitfall for atypical mesothelial cells

Pleomorphic lobular carcinoma (PLC) is a subtype of infiltrating lobular carcinoma because of its dyscohesiveness, linear infiltration pattern, and lack of membranous E-cadherin staining. However, it differs from classic lobular carcinoma because of its high-grade cytology and more aggressive clinical behavior. In breast fine-needle aspiration biopsies, PLC can be confused with invasive ductal carcinoma, particularly the apocrine variant. In this report, we illustrate how metastatic PLC in body fluid specimens shows many of the same cytomorphologic changes that occur in reactive/atypical mesothelial cells. Fortunately, the immunohistochemical staining pattern of PLC can help to distinguish it from other possible diagnoses in the differential, such as reactive/atypical mesothelial cells and other metastatic neoplasms. However, the frequent apocrine features seen in this variant of breast carcinoma can cause nonspecific immunohistochemical positivity that may make the interpretation difficult. This is the first report illustrating the cytopathology and immunohistochemical findings of pleomorphic lobular carcinoma in body cavity fluid cytology. Our case highlights the important issues and pitfalls to be aware of when making this diagnosis.     

Histopathological and clonal study of combined lobular and ductal carcinoma of the breast

Lobular carcinoma in situ (LCIS) clinically constitutes a risk factor for the subsequent development of either invasive lobular carcinoma (ILC) or invasive ductal carcinoma (IDC). In order to approach the possibility of this common precursor of both ILC and IDC, we investigated combined lobular and ductal carcinomas. Thirty‐two cases of lobular carcinoma were picked up out of 773 cases of operated breast carcinomas. The histopathological detailed re‐examination using immunostain of E‐cadherin and β‐catenin revealed a rather high frequency of combined lobular carcinomas than previous reports. Clinicopathologically, combined lobular carcinomas were younger and smaller than pure lobular carcinomas, and the cytological atypia was relatively low. These results suggested that combined lobular carcinomas could be detected in the earlier stage of breast cancer. Furthermore, the lobular and ductal components of combined carcinomas coexisted in the neighborhood and were distributed contiguously. The immunohistochemical phenotypes of both components were accorded in most combined cases. A genetic analysis using methylation‐specific PCR on the HUMARA gene demonstrated that the same allele was inactivated in both lobular and ductal components in all detectable cases of combined carcinoma. Therefore, it is reasonable to assume that both lobular and ductal components of combined carcinomas are clonal and derived from the LCIS as the common precursor lesion, which may contradict the conventional concept that the lobular and ductal carcinomas arise from distinct differentiation pathways.     

Histiocytoid breast carcinoma: a case report showing immunohistochemical profiles

Histiocytoid breast carcinoma (HBC) is a rare type of breast cancer with a controversial histogenesis. Here we describe a case report of a 65-year old woman with HBC. The patient presented with two masses in the right breast. Histopathologically, the tumors consisted of a diffuse infiltration of large tumor cells and histological components of carcinoma in situ and atypical lobular hyperplasia were also observed. The infiltration pattern was similar to that of invasive lobular carcinoma with targetoid and Indian file arrangements. The invasive histiocytoid cells had finely granular, eosinophilic to vesicular cytoplasm and nuclei with a bland uniform appearance, a single small eosinophilic nucleolus and finely granular chromatin. We compared the immunohistochemical profiles of 17 breast cancer markers between invasive carcinoma, carcinoma in situ, atypical lobular hyperplasia and normal breast epithelium. Although they all shared the same reactivity for many of the proteins, they exhibited differences in GCDFP-15, E-cadherin, P120, CEA, HER-2, ER and PR expression, and these are discussed. This is the first case study of two HBC masses occurring in one breast simultaneously. By analyzing and comparing their morphologic characteristics and spectrum of immunohistochemical expression, our study supports the view that HBC is a variant of lobular carcinoma and our findings may assist in future diagnoses of HBC.     

Lobular carcinoma in situ in sclerosing adenosis

The initial presentation of breast malignancy as noninvasive carcinoma in an area of sclerosing adenosis is unusual. Especially, lobular carcinoma in situ in sclerosing adenosis sometimes can be a potential source of confusion with invasive lobular carcinoma. We report a case of lobular carcinoma in situ presenting in adenosis exhibiting patterns akin to invasive lobular carcinoma, thus leading to potential misdiagnosis. Overall architecture of the lesion as seen at lower power and immunohistochemistry can be useful to distinguish between sclerosing adenosis with lobular carcinoma in situ and infiltrating lobular carcinoma.     

Molecular cytogenetic comparison of apocrine hyperplasia and apocrine carcinoma of the breast

The relationship of apocrine metaplasia to invasive breast cancer is controversial. Different authors have reported that apocrine differentiation in proliferative lesions may be a risk factor, a precursor lesion, or have no association with malignancy. The aim of this study was to compare the genetic alterations in benign apocrine hyperplasia with apocrine ductal carcinoma in situ (DCIS) and invasive apocrine carcinomas of the breast using comparative genomic hybridization. The mean number of alterations in apocrine hyperplasia was 4.1 (n = 10) compared to 10.2 in apocrine DCIS (n = 10) and 14.8 (n = 4) in invasive carcinoma. The most common alterations in apocrine hyperplasia were gains of 2q, 13q, and 1p and losses of 1p, 17q, 22q, 2p, 10q, and 16q. Apocrine DCIS and invasive carcinomas showed gains of 1q, 2q, 1p, and losses of 1p, 22q, 17q, 12q, and 16q as their most common DNA copy number changes. Apocrine hyperplasia is considered to be a benign lesion and its relationship to invasive carcinoma remains unclear. Our data suggest that some apocrine hyperplasias may be clonal proliferations. The mean number of alterations are lower in apocrine hyperplasia, however the changes show considerable overlap with those identified in in situ and invasive apocrine carcinoma. These alterations are also commonly seen in nonapocrine breast cancer. The data are consistent with apocrine hyperplasia as a putative nonobligate precursor of apocrine carcinoma.     

E-cadherin expression in pleomorphic lobular carcinoma: an aid to differentiation from ductal carcinoma

Pleomorphic lobular carcinoma is a recently described entity separated from classical lobular carcinoma by cytologic pleomorphism. It can have an aggressive clinical course with a higher frequency of recurrence. Histologic differentiation with ductal carcinoma may be difficult, but it is important for this differentiation to be made. E-cadherin is a transmembrane glycoprotein, and complete loss of E-cadherin expression has been observed in invasive lobular carcinoma and lobular carcinoma in situ. Ductal carcinoma retains at least some expression of E-cadherin. We examined the pattern of E-cadherin expression in a series of 14 cases of pleomorphic lobular carcinoma by immunohistochemistry. Twelve of the 14 cases showed no staining (86%); the remaining two cases exhibited 10% to 25% positive cells. In cases with histologic equivocal features, immunohistochemical detection of E-cadherin expression can be a useful diagnostic aid for the differentiation of pleomorphic lobular and ductal carcinoma.     

The impact of large sections on the study of in situ and invasive duct carcinoma of the breast

Large histologic sections (LHSs) are increasingly used in the study of normal and neoplastic breast tissue. LHSs allow the direct visualization of a large part of the breast glandular tree. Accordingly, LHSs have shown that in situ and invasive lobular carcinoma is a multilobar (and hence multifocal) neoplastic lesion in more than 50% of the cases, and that poorly differentiated duct carcinoma in situ (DCIS grade 3) is frequently unifocal, whereas it is often multifocal when the in situ lesion is a well-differentiated type (DCIS grade 1). Forty-five mastectomies were studied with large sections. Mastectomies were performed when quadrantectomy did not guarantee radical excision of the tumor with adequate cosmesis because of the large size of the lesion or because the neoplastic lesion was located below the nipple. Excluded were cases of lobular neoplasia or invasive lobular carcinoma, because they were reported separately, and cases of mastectomies performed for sarcoma or recurrent phyllodes tumor. All cases had undergone a preoperative diagnostic procedure (fine needle aspiration), and the relative positive material was reviewed. All 45 cases showed in situ duct carcinoma and 37 showed evidence of invasive duct carcinoma. Forty-two cases of DCIS were multifocal, whereas only 4 invasive duct carcinoma were shown as multifocal. When DCIS lesions were subdivided into 3 grades, no statistical significance was seen among the 3 groups of DCIS in regard to multifocality. Nevertheless, DCIS grade 1 was a widespread condition involving more than one lobe and quadrant, whereas DCIS grades 2 and 3 appeared more localized. DCIS grade 1 was more similar to that previously observed in lobular in situ neoplasia/lobular in situ carcinoma. In 66.6% of the cases, DCIS foci were found within the invasive areas, indicating a more than fortuitous occurrence (2-sided P=.0357).     

Frequent E-cadherin gene inactivation by loss of heterozygosity in pleomorphic lobular carcinoma of the breast.

Pleomorphic lobular carcinoma of the breast is a variant of infiltrating lobular carcinoma that has poor prognosis. The pleomorphic appearance of this variant hinders its correct identification and differentiation from ductal carcinoma. The analysis of E-cadherin glycoprotein expression is a powerful tool for distinguishing lobular from ductal carcinomas, because complete loss of E-cadherin expression occurs in most infiltrating lobular tumors and lobular carcinomas in situ, but not in ductal tumors. In the present study, we have evaluated E-cadherin expression by immunohistochemistry in a series of 29 pleomorphic lobular breast carcinomas, including 7 cases with an in situ component. Complete loss of E-cadherin expression was observed in all the cases (29/29, 100%), in invasive and in situ components. To understand better the mechanisms underlying E-cadherin inactivation in this tumor type, the frequency of loss of heterozygosity at the E-cadherin gene locus (16q22.1) was analyzed. All informative tumors (27/27, 100%) showed loss of heterozygosity, thus implying a strong association between loss of E-cadherin expression and loss of heterozygosity at 16q22.1. Moreover, loss of heterozygosity was detected in all in situ components analyzed. These results imply that in terms of E-cadherin inactivation, pleomorphic lobular tumors are identical to classic infiltrating lobular carcinomas and distinct from ductal tumors, and therefore they should be considered a variant of lobular carcinoma of the breast, despite their aggressive behavior.     

Lobular neoplasia in breast core needle biopsy specimens is not associated with an increased risk of ductal carcinoma in situ or invasive carcinoma

Recent reports suggest that the finding of lobular neoplasia (atypical lobular hyperplasia [ALH] or bular carcinoma in situ [LCIS]) in breast core needle biopsy specimens may be associated with an increased risk of both ductal carcinoma in situ (DCIS) or invasive carcinoma at excision. We reviewed our breast core biopsy material to see if we could confirm this finding. from 4,297 biopsies, 71 cases of lobular neoplasia lone and 35 cases of lobular neoplasia associated with typical ductal hyperplasia were identified. Biopsy follow-up revealed DCIS or invasive carcinoma in none of 6 cases of ALH, none of 9 cases of LCIS, and DCIS in 1 of 11 cases with both atypical ductal hyperplasia and LCIS. Our results suggest that patients with lobular eoplasia in breast core biopsy specimens are not at increased risk of either DCIS or invasive carcinoma at excision, and patients with this finding and no other linical or pathologic indications for biopsy can be llowed up rather than routinely undergo excision.     

Invasive lobular carcinoma of the breast. An analysis of 29 cases

Twenty-nine cases of invasive lobular carcinoma were analyzed, based on three aspects of the histology: 1) cellular features such as a monotonous proliferation of uniform small cells, 2) a single file or targetoid arrangement, and 3) loss of cell cohesion or dissociation of tumor cells. Twenty-four tumors which fulfilled these three criteria were appraised as cases of conventional lobular carcinoma, in a classic sense, while five others were a variant of this tumor. Individual tumor cells of lobular carcinoma were estimated to be well differentiated, both morphologically and functionally, revealing well developed intracytoplasmic organelles and a high percentage of alpha-lactalbumin content in the cytoplasm. Nevertheless, the tumor itself was characterized by a lack of any particular structural differentiation in the arrangement of cells. Based on the observation of the histologic features, invasive lobular carcinoma was subclassified into three groups, in situ predominant, intermediate, and diffuse infiltrating and with a definite correlation to the age of the patient and to the prognosis. Validity of this classification indicates that lobular carcinoma progresses gradually, even in the invasive phase, and can be categorized as a slowly growing subset of mammary carcinoma.