D2-40 expression by breast myoepithelium: potential pitfalls in distinguishing intralymphatic carcinoma from in situ carcinoma

Case report: Metastatic ovarian mucinous carcinoma to the breast: diagnostic challenges and pitfalls

Metastases to the breast from extramammary sources are extremely rare, with the ovary, primarily high-grade serous carcinoma, being the most common origin. We report a case of breast metastases from advanced stage ovarian mucinous carcinoma in a 48-year-old female- a case hitherto unreported in the literature. The case is noteworthy for its atypical presentation marked by an areolar rash, clinically suggestive of Paget disease of the nipple. This unique clinical scenario, coupled with histopathological examination revealing in-situ-like carcinoma component, posed a diagnostic challenge in discerning the tumour origin. We emphasize the need for heightened awareness among pathologists to avoid misdiagnosing metastatic carcinomas as primary breast tumours, a potential pitfall with significant clinical implications.

Neoadjuvant Therapy in Breast Cancer: Histologic Changes and Clinical Implications

Cytotoxic or endocrine therapy before surgery (neoadjuvant) for breast cancer has become standard of care, affording the opportunity to assess and quantify response in the subsequent resection specimen. Correlation with radiology, cassette mapping, and histologic review with a semi-quantitative reporting system such as residual cancer burden (RCB) provides important prognostic data that may guide further therapy. The tumor bed should be identified histologically, often as a collagenized zone devoid of normal breast epithelium, with increased vasculature. Identification of residual treated carcinoma may require careful high power examination, as residual tumor cells may be small and dyscohesive; features are widely variable and include hyperchromatic small, large, or multiple nuclei with clear, foamy, or eosinophilic cytoplasm. Calculation of RCB requires residual carcinoma span in 2 dimensions, estimated carcinoma cellularity (% area), number of involved lymph nodes, and span of largest nodal carcinoma. These RCB parameters may differ from AJCC staging measurements, which depend on only contiguous carcinoma in breast and lymph nodes.

The prognostic influence of lymphatic endothelium-specific hyaluronan receptor 1 in cancer: A systematic review

Lymphangiogenesis is a key process in cancer development and metastasis. Lymphatic vessel endothelial hyaluronan receptor 1 (LYVE‐1) is a widely used marker for lymphatic endothelial cells (LEC), which also mediates immune and cancer cell migration. Recently, LYVE‐1–positive tumor cells were shown to acquire LEC‐like phenotype and exploit this receptor for lymphatic dissemination. Furthermore, selective targeting of LYVE‐1 impaired the growth of cancer‐related vasculature and reduced metastasis in vivo, signifying its role in therapeutic and prognostic applications. Although numerous studies have investigated the role of LYVE‐1 in cancer, a unifying detailed review of its prognostic utility is lacking to date. Thus, we compiled and critically appraised evidence from clinical studies comprising a total of 2352 patients diagnosed with different types of cancer and using a variety of experimental approaches. Collectively, most studies revealed a significant association between LYVE‐1 overexpression and dismal outcome of at least one survival estimate. Furthermore, the importance of vasculature location, intra‐ or peritumoral, and the influence of various lymphangiogenesis‐related parameters, such as lymphatic vessel density and invasion, were discussed. However, the specificity of LYVE‐1 staining is challenged by its expression in non‐LEC cells, implying the need for double labelling to better estimate its prognostic significance. In conclusion, this is to our knowledge the first comprehensive systematic review on the prognostic value of LYVE‐1 in cancer. More well‐designed studies across different populations and the development of standardized protocols would be paramount for the consistency of LYVE‐1 findings and for its potential transferability to clinical practice in future.

Papillary Breast Tumors: Continuing Controversies and Commentary on WHO's 2019 Criteria and Classification

The category of papillary breast tumors includes a limited number of entities. Nonetheless, this relatively uncommon group of tumors seems to instigate a disproportionate degree of diagnostic disquiet. As a group, papillary breast tumors suffer from a relatively high rate of discordant interpretation. The latter is due to the inherent complexity of the lesions compounded by conflicting criteria as well as simmering controversies. For instance, "encapsulated" papillary carcinoma remains contentious with regards to whether these are noninvasive or not, and the assessment of the extent of the invasive versus noninvasive components in many solid papillary carcinomas can be problematic. The latest classification system of breast tumors enunciated by the World Health Organization (WHO), that is, Breast Tumors, which appeared in 2019, mainly sought to incorporate advances in basic and clinical sciences into diagnostic criteria for the entire spectrum of breast neoplasms-including papillary ones. The latter category of tumors is discussed at some length in Breast Tumors; however, it still appears to suffer from some lack of clarity in its subclassification. It is our intent in this communication to provide an overview of the controversies around papillary breast tumors, and offer comments on its coverage in Breast Tumors-so that any tangible or perceived ambiguities therein could be addressed in its next edition.

D2-40 A Helpful Marker in Assessment of Lymphatic Vessel Invasion in Carcinoma of Breast

Background & Objective:

Breast cancer is the most common malignancy among Iranian women and worldwide. Lymphatic vessel invasion (LVI) was found to be an independent prognostic factor in many carcinomas, including invasive carcinoma of the breast. The aim of this study was to compare the hematoxylin and eosin (H&E) staining method and use of the immunohistochemical (IHC) marker ofD2-40, for evaluation of LVI in breast carcinoma specimens.

Methods:

The study was conducted on 50 patients undergone surgery between the years 2010 and 2015 in Rohani Hospital, Babol, Iran with invasive carcinoma of the breast with Census sampling method. LVI was assessed by two surgical pathologists, using H&E- stained sections and two IHC markers, i.e., D2-40 and CD31.

Results:

LVI was detected in 25 (50%) patients by H&E and in 14 (28%) patients by D2-40. Twelve out of 25 patients with positive LVI in H&E were confirmed by D2-40 and 2 out of 25 patients with negative lymphatic vessel in H&E. Only one case showed weak staining of CD31 proving LVI. These results showed a significant difference between the H&E staining and D2-40 IHC study for LVI detection (P=0.004).

Conclusion:

The D2-40 IHC marker is helpful in the diagnosis and confirmation of LVI in invasive carcinoma of the breast. CD31 is not suitable for the evaluation of lymphatic vessels.

Integrin β4 Is an Effective and Efficient Marker in Synchronously Highlighting Lymphatic and Blood Vascular Invasion, and Perineural Aggression in Malignancy

Lymphovascular invasion (LVI) and perineural invasion (PNI) are 2 important pathologic parameters and need to be accurately assessed in multiple malignancies. Integrin β4, a member of the integrin family, has been reported to be positively expressed in vascular endothelia, peripheral nerves, and a collection of epithelia. However, little is known about the effectiveness of β4 immunostaining on the recognition of LVI and PNI. Herein, we explored the applicability of β4 immunostaining in stomach, thyroid, and breast cancers. Parallel immunostaining of D2-40, CD34, and S-100 was performed as controls for lymphatic endothelia, vascular endothelia, and neural fibers, respectively. The results demonstrated that β4 concurrently stained the lymphatic and vascular endothelia, and the peripheral nerves. Both LVI and PNI were clearly and accurately outlined by β4 immunostaining. β4 was also expressed in the majority of tumor cells, enabling recognition of LVI and PNI encroached by small tumor clusters. In contrast to D2-40 and CD34, β4 staining was not observed in stromal cells, and therefore it facilitated differentiation between the shrinkage cleft and LVI. According to our results, β4 staining strikingly increased the diagnostic accuracy and interobserver concordance for LVI and PNI compared with hematoxylin and eosin staining alone. Finally, the applicability of β4 was confirmed in 9 other types of malignancies, including cancers of the colon, prostate, esophagus, lung, kidney, uterus, tongue, bladder, and liver. Collectively, β4 is a reliable marker for synchronous detection and diagnosis of LVI and PNI.

Precursor Lesions of the Low-Grade Breast Neoplasia Pathway

The nonobligate precursor lesions columnar cell change/hyperplasia and flat epithelial atypia, atypical ductal hyperplasia and atypical lobular hyperplasia, lobular carcinoma in situ, and low-grade ductal carcinoma in situ share morphologic, immunophenotypic, and molecular features supporting the existence of a low-grade breast neoplasia pathway. The practical implication for pathologists is that the identification of one of these lesions should prompt careful search for others. From a clinical management perspective, however, their designation as "precursor lesions" should not be overemphasized, as the risk of progression among the earliest lesions is exceedingly low. Factors determining which lesions will progress remain unknown.

The optimum marker for the detection of lymphatic vessels

Podoplanin, lymphatic vessel endothelial hyaluronic acid receptor-1, prospero-related homeobox-1 and vascular endothelial growth factor receptor 3 have been demonstrated to have crucial roles in the development of the lymphatic system and lymphangiogenesis process by combining with their corresponding receptors. Thus, the four markers have been widely used in labelling lymphatic vessels for the detection of lymphangiogenesis and lymphatic vessel invasion. Numerous authors have aimed to identify the roles of these four markers in the lymphatic system and the mechanisms have been partly clarified at the molecular level. The aim of the present review was to comprehensively clarify the characteristics and latent action modes of the four markers in order to determine which is the best one for the detection of lymphangiogenesis and lymphatic vessel invasion.

Macroscopic lymphovascular invasion visualized on mammogram and magnetic resonance imaging: Initially misidentified as ductal carcinoma in situ but properly diagnosed by immunohistochemistry

Objectives:

Lymphovascular invasion (LVI) is a pathologic, microscopic finding associated with invasive cancer, and is a poor prognostic indicator, but has no reported imaging findings. This report presents the first documented case of LVI with seen by imaging. Linear branching microcalcifications were identified on mammography and clumped enhancement was noted on MRI, both imaging findings that are highly predictive of ductal carcinoma in situ (DCIS).

Methods:

Ultrasound guided core biopsy of the dominant mass was performed, confirming invasive ductal malignancy. Stereotactic biopsy performed on the microcalcifications was initially interpreted by pathology as DCIS.

Results:

Patient underwent mastectomy. Pathologic evaluation of the surgical specimen confirmed the invasive ductal malignancy. Microcalcifications were re-evaluated with immunohistochemistry (IHC) and re-classified as LVI. Radiology images and IHC stains are shown.

Conclusion:

This is the first report of LVI identified by imaging with findings that mimicked DCIS and initially mis-identified as DCIS by pathology as well. The implications of this overlap in radiologic appearance are discussed.

Molecular Portrait of the Normal Human Breast Tissue and Its Influence on Breast Carcinogenesis

Normal human breast tissue consists of epithelial and nonepithelial cells with different molecular profiles and differentiation grades. This molecular heterogeneity is known to yield abnormal clones that may contribute to the development of breast carcinomas. Stem cells that are found in developing and mature breast tissue are either positive or negative for cytokeratin 19 depending on their subtype. These cells are able to generate carcinogenesis along with mature cells. However, scientific data remains controversial regarding the monoclonal or polyclonal origin of breast carcinomas. The majority of breast carcinomas originate from epithelial cells that normally express BRCA1. The consecutive loss of the BRCA1 gene leads to various abnormalities in epithelial cells. Normal breast epithelial cells also express hypoxia inducible factor (HIF) 1α and HIF-2α that are associated with a high metastatic rate and a poor prognosis for malignant lesions. The nuclear expression of estrogen receptor (ER) and progesterone receptor (PR) in normal human breast tissue is maintained in malignant tissue as well. Several controversies regarding the ability of ER and PR status to predict breast cancer outcome remain. Both ER and PR act as modulators of cell activity in normal human breast tissue. Ki-67 positivity is strongly correlated with tumor grade although its specific role in applied therapy requires further studies. Human epidermal growth factor receptor 2 (HER2) oncoprotein is less expressed in normal human breast specimens but is highly expressed in certain malignant lesions of the breast. Unlike HER2, epidermal growth factor receptor expression is similar in both normal and malignant tissues. Molecular heterogeneity is not only found in breast carcinomas but also in normal breast tissue. Therefore, the molecular mapping of normal human breast tissue might represent a key research area to fully elucidate the mechanisms of breast carcinogenesis.

Myoepithelial differentiation in cribriform, tubular and solid pattern of adenoid cystic carcinoma: A potential involvement in histological grading and prognosis

Adenoid cystic carcinoma (AdCC) is known as a biphasic tumor composed of ductal and myoepithelial cells. The present study aimed to evaluate the amount and distribution of the myoepithelial cells in cribriform, tubular and solid subtypes of AdCC and analyze their relationship with histological grading and prognosis. A panel of myoepithelial markers including CK5/6, p63, p40, D2-40, calponin, α-SMA, S-100, and vimentin, together with a luminal cell marker CK7, and Ki-67 were used for immunohistochemical study in 109 AdCCs that included 38 cribriform, 36 tubular and 35 solid subtypes. The myoepithelial cells were labeled and found lined cystic-like paces, located at the periphery of the cribriform arrangements, and presented at the nonluminal cells of the two-layered tubular structures, while absent or dispersed in the solid pattern. Meantime, the solid subtype presented a higher proliferation rate assessed by mitotic count and Ki-67 labeling index, followed by poorer overall survival and recurrent-free survival. Furthermore, CK7 expression was found higher in solid pattern than in cribriform-tubular subtype, which showed negative correlation with the myoepithelial markers including D2-40, Calponin, α-SMA, p63, p40 and vimentin. The solid pattern of AdCC showed gland differentiation but loss of myoepithelial differentiation with a higher proliferation and more aggressiveness as well as poorer prognosis compared with the cribriform-tubular subtypes, which implies that loss of MEC differentiation might contribute to the poor prognosis of the solid subtype of AdCC. However, further studies are required to clarify its exact role in AdCC progression.

The different role of intratumoral and peritumoral lymphangiogenesis in gastric cancer progression and prognosis

Background

Tumor-induced lymphangiogenesis plays a crucial role in metastasis and tumor progression. However, the significance of intratumoral lymphovascular density (I-LVD) and peritumoral lymphovascular density (P-LVD) has been controversial in gastric cancer. The purpose of this study was to investigate the differences of clinicopathologic characteristics with respect to I-LVD and P-LVD in gastric cancer.

Methods

Samples of I-LVD and P-LVD from 66 patients who had undergone radical gastrectomy for gastric cancer were assessed after staining with D2-40, an immunostaining marker for lymphatic endothelium. The mean number of lymphatic vessels in three hotspots was calculated in intratumoral and peritumoral areas.

Results

The peritumoral lymphatics were enlarged with dilated lumens compared to the intratumoral lymphatics. I-LVD was positively correlated with diffuse gastric cancer subtype, tumor stage, lymphovascular invasion, tumor node metastasis stage, and overall survival (P <0.05). P-LVD was associated with lymphovascular invasion, node stage, and disease-free survival (P <0.05).

Conclusions

We conclude that P-LVD had an important role in lymph node metastasis, while I-LVD was more associated with depth of tumor invasion. However, both LVDs contributed to gastric cancer progression and prognosis.

A Pilot Study of Ultrasound-Guided Cryoablation of Invasive Ductal Carcinomas up to 15 mm With MRI Follow-Up and Subsequent Surgical Resection

OBJECTIVE

The purpose of this study was to evaluate the effectiveness of ultrasound-guided cryoablation in treating small invasive ductal carcinoma and to assess the role of contrast-enhanced (CE) MRI in determining the outcome of cryoablation.

SUBJECTS AND METHODS

Twenty consecutive participants with invasive ductal carcinomas up to 15 mm, with limited or no ductal carcinoma in situ (DCIS), underwent ultrasound-guided cryoablation. Preablation mammography, ultrasound, and CE-MRI were performed to assess eligibility. Clinical status was evaluated at 1 day, 7-10 days, and 2 weeks after ablation. CE-MRI was performed 25-40 days after ablation, followed by surgical resection within 5 days.

RESULTS

Ultrasound-guided cryoablation was uniformly technically successful, and postablation clinical status was good to excellent in all participants. Cryoablation was not clinically successful in 15% (three of 20 patients). Three participants had residual cancer at the periphery of the cryoablation site. Two participants had viable nonmalignant tissue within the central zone of cryoablation-induced necrosis. Postablation CE-MRI had a sensitivity of 0% (0/3) and specificity of 88% (15/17). The predictive value of negative findings on CE-MRI was 83% (15/18). Correlations between cancer characteristics, cryoablation procedural variables, postablation CE-MRI findings, and surgical specimen features were not statistically significant. There were also no significant differences in participants with or without residual cancer.

CONCLUSION

In our pilot experience, ultrasound-guided cryoablation of invasive ductal carcinomas up to 15 mm has a clinical failure rate of 15% but is technically feasible and well tolerated by patients. The majority of cryoablation failures are manifest as DCIS outside the cryoablation field. Postablation CE-MRI does not reliably predict cryoablation outcome.

Lymphatic endothelial cancerization in papillary thyroid carcinoma: hidden evidence of lymphatic invasion

We hypothesize that cystic structures in metastatic papillary thyroid carcinoma (PTC) develop along the framework of lymphatic channels. To investigate this phenomenon, different categories of PTC were immunostained for D2-40 and TTF1. In this study, reactivity for D2-40 was considered as positive when there is membranous staining as often seen in lymphatic endothelial cells. Thirty cases of PTC with lymph node metastasis or with potential for lymphatic invasion and 20 cases metastatic PTC in lymph nodes were reviewed and found to show double/mosaic immunoreactivity for TTF1/D2-40 in 40-100% of cases. PTC metastasis in lymph nodes with cysts and some branching lymphatic-like channels lined by follicular cells with or without nuclear features of PTC were diffusely reactive to TTF1, and focally to D2-40. For primary and metastatic PTC, focal membranous D2-40 reactivity was also demonstrated in cysts or cleft linings. For25 thyroid neoplasms with no known potential for lymphatic invasion, there was no such immunoreactivity. The mosaic or double immunoreactivity for TTF1/D2-40 suggests lymphatic cancerization and possible endothelial mimicry of follicular cells. Mosaic/double immunoreactivity is helpful to detect the hidden pattern of lymphatic invasion masquerading as 'benign-appearing' follicles and supports our hypothesis of malignant cells developing along the lymphatic framework.

Application of immunohistochemistry in breast pathology: a review and update

CONTEXT

Immunohistochemistry is a valuable tool in routine breast pathology, used for both diagnostic and prognostic parameters. The diagnostic immunomarkers are the scope of this review. Most breast lesions can be diagnosed on routine hematoxylin-eosin sections; however, in several scenarios, such as morphologically equivocal cases or metastatic tumors of unknown primary, the appropriate application of immunohistochemistry adds true value in reaching an accurate diagnosis.

OBJECTIVE

To evaluate the diagnostic utility of the most commonly studied immunomarkers in the field of breast pathology by review of the literature, using the database of indexed articles in PubMed (US National Library of Medicine, Bethesda, Maryland) from 1976 to 2013.

DATA SOURCES

Literature review, and author's research data and personal practice experience.

CONCLUSIONS

The appropriate use of immunohistochemistry by applying a panel of immunomarkers and using a standardized technical and interpretational method will complement the morphologic assessment and aid in the accurate classification of difficult breast lesions and the identification of metastasis from a breast primary.

Immunohistochemical detection improves the prognostic value of lymphatic and blood vessel invasion in primary ductal breast cancer

Background

Lymphovascular invasion (LBVI) including lymphatic (LVI) and blood (BVI) vessel invasion is a critical step in cancer metastasis. In breast cancer, the optimal detection method of LBVI remains unclear. This research aimed to compare the prognostic value of different assessments of the LVI and BVI in patients with early breast cancer.

Methods

The study cohort included 360 patients with a median follow-up of 168 months. LBVI on H&E sections (LBVI_H&_E) was reviewed centrally and blinded to the pathology report. Immunohistochemical staining for D2-40 and Factor VIII was performed to identify LVI_D2–40 and BVI_FVIII.

Results

LBVI_H&_E, LVI_D2–40 and BVI_FVIII were present in 102 (28%), 127 (35%) and 59 (16%) patients respectively. In node-negative patients (206), LBVI_H&_E, LVI_D2–40 and BVI_FVIII were present in 41 (20%), 53 (26%) and 21 (10%) respectively. In triple-negative patients (120), LBVI_H&_E, LVI_D2–40 and BVI_FVIII were present in 35 (29%), 46 (38%) and 16 (13%) respectively. LBVI_H&_E was significantly associated with tumour recurrence in the whole cohort (P < 0.001), node-negative patients (P = 0.001) and triple-negative patients (P = 0.004). LVI_D2–40 and BVI_FVIII were significantly associated with tumour recurrence in whole cohort, node-negative (all P < 0.001) and triple-negative patients (P = 0.002). In multivariate survival analysis, only LVI_D2–40 and BVI_FVIII were independent predictors of cancer specific survival in the whole cohort (P = 0.023 and P < 0.001 respectively), node-negative patients (P = 0.004 and P = 0.001 respectively) and triple-negative patients (P = 0.014 and P = 0.001 respectively).

Conclusion

Assessment of LVI and BVI by IHC using D2-40 and Factor VIII improves prediction of outcome in patients with node-negative and triple-negative breast cancer.

Expression and clinical significance of matrix metalloproteinase-9 in lymphatic invasiveness and metastasis of breast cancer

BACKGROUND

Matrix metalloproteinase 9 (MMP-9) is a type-IV collagenase that is highly expressed in breast cancer, but its exact role in tumor progression and metastasis is unclear.

METHODS

MMP-9 mRNA and protein expression was examined by real-time reverse transcriptase PCR and immunohistochemical staining, respectively, in 41 breast cancer specimens with matched peritumoral benign breast epithelial tissue and suspicious metastatic axillary lymph nodes. Lymph vessels were labeled with D2-40 and lymphatic microvessel density (LMVD) was calculated. Correlation of MMP-9 protein expression with clinicopathological parameters and LMVD was also evaluated.

RESULTS

MMP-9(+) staining in breast cancer specimens (35/41, 85.4%) was higher than in matched epithelium (21/41, 51.2%; P<0.05) and lymph nodes (13/41, 31.7%; P<0.001). Higher MMP-9 mRNA expression was also detected in tumor specimens compared with matched epithelial tissues and lymph nodes (P<0.05). Elevated MMP-9 expression was correlated with lymph node metastasis and LMVD (P<0.05).

CONCLUSION

MMP-9 was overexpressed in breast cancer specimens compared with peritumoral benign breast epithelium and lymph nodes. Moreover, its expression in the matched epithelium and lymph nodes was positively associated with lymph node metastasis, and its expression in lymph nodes was positively associated with lymphangiogenesis in breast cancer. Thus, MMP-9 is a potential marker for breast cancer progression.

Diagnostic role of immunohistochemistry in the evaluation of breast pathology specimens

CONTEXT

Immunohistochemistry plays a vital role in the evaluation of breast pathology specimens.

OBJECTIVE

To discuss the role of myoepithelial cell markers in the evaluation of various breast lesions. Other markers, such as E-cadherin and those used to differentiate mammary carcinoma from metastatic tumors to the breast, and markers used in the differential diagnosis of Paget disease, are also discussed.

DATA SOURCES

Data were obtained from review of the pertinent peer-reviewed literature.

CONCLUSIONS

Myoepithelial cell markers vary in their sensitivity and specificity, and one should be aware of the potential pitfalls in interpretation. Using panels of 2 or more myoepithelial cell markers is always recommended, either singly or in cocktail forms. Although negative E-cadherin staining supports the diagnosis of lobular origin, positive staining does not rule it out. Immunohistochemistry can be helpful in differentiating Paget disease from its mimics. Although metastatic tumors to the breast are rare, a triple-negative immunophenotype and absence of an in situ component should be a "red flag" for such possibility, especially in patients with clinical history of an extramammary malignancy.

Metastases to and from the Breast

Breast cancer is a common source of systemic metastatic disease. Distinguishing metastatic breast cancer from other types of malignancies can be diagnostically challenging but is important for correct treatment and prognosis. Nonmammary tumors can also metastasize to the breast, although this is a rare phenomenon. Differentiating a metastasis to the breast from a primary breast cancer can likewise be difficult. Knowledge of the clinical history and careful morphologic evaluation are the cornerstones of diagnosis. A panel of immunohistochemical stains tailored to the differential diagnosis at hand can provide helpful information in ambiguous cases.

Less Common Variants and Mimics of DCIS

The purpose of this review is to discuss the less common variants and mimics of ductal carcinoma in situ (DCIS). DCIS lesions are heterogeneous in clinical presentation and behavior, morphology, biomarker profile, and identified genetic aberrations. DCIS is most easily recognized when presenting with classical features. The diagnosis is more challenging when a lesion displays less common cytologic features and has architectural patterns that overlap with other benign or malignant entities.

Expression and clinical significance of extracellular matrix protein 1 and vascular endothelial growth factor-C in lymphatic metastasis of human breast cancer

BACKGROUND

Extracellular matrix protein 1 (ECM1) and vascular endothelial growth factor-C (VEGF-C) are secretory glycoproteins that are associated with lymphangiogenesis; these proteins could, therefore, play important roles in the lymphatic dissemination of tumors. However, very little is known about their potential roles in lymphangiogenesis. The aim of this study was to investigate whether correlations exist between ECM1 and VEGF-C in human breast cancer, lymphangiogenesis, and the clinicopathological characteristics of the disease.

METHODS

ECM1 and VEGF-C mRNA and protein expression levels in 41 patients were investigated using real-time reverse transcriptase polymerase chain reaction (RT-PCR), or immunohistochemical (IHC) staining of breast cancer tissue, matched noncancerous breast epithelial tissues, and suspicious metastatic axillary lymph nodes. D2-40 labelled lymph vessels and lymphatic microvessel density (LMVD) were counted. Correlations between ECM1 or VEGF-C protein expression levels, LMVD, and clinicopathological parameters were statistically tested.

RESULTS

The rate of ECM1 positive staining in breast cancer tissues was higher (31/41, 75.6%) than that in the corresponding epithelial tissues (4/41, 9.8%, P < 0.001) and lymph nodes (13/41, 31.7%, P < 0.001). Similarly, the VEGF-C expression rate in cancer specimens was higher (33/41, 80.5%) than in epithelial tissues (19/41, 46.3%, P < 0.01) or lymph nodes (15/41, 36.6%, P < 0.01). Higher ECM1 and VEGF-C mRNA expression levels were also detected in the tumor tissues, compared to the non-cancerous tissue types or lymph nodes (P < 0.05). ECM1 protein expression was positively correlated with the estrogen receptor status (P < 0.05) and LMVD (P < 0.05). LMVD in the ECM1- and VEGF-C-positive tumor specimens was higher than that in the tissue types with negative staining (P < 0.05).

CONCLUSIONS

Both ECM1 and VEGF-C were overexpressed in breast cancer tissue samples. ECM1 expression was positively correlated with estrogen responsiveness and the metastatic properties of breast cancer. We conclude, therefore, that ECM1 and VEGF-C may have a synergistic effect on lymphangiogenesis to facilitate lymphatic metastasis of breast cancer.

Merkel cell carcinoma induces lymphatic microvessel formation

BACKGROUND

Merkel cell carcinoma (MCC) is a rare, highly malignant neuroendocrine tumor of the skin characterized by frequent lymphatic metastasis.

OBJECTIVE

We sought to identify lymphovascular anatomy and expression profiles of lymphangiogenic cytokines to give an opinion on lymphangiogenesis in MCC.

METHODS

We studied lymphatic microanatomy and lymphangiogenic cytokines in 27 MCC by immunohistology or immunofluorescence (D2-40, lymphatic vessel endothelial hyaluronan receptor [LYVE-1], vascular endothelial growth factor [VEGF] receptor-3, VEGF-C, VEGF-D, Ki67/MiB-1, CD68/PG-M1, CD68/KP1, CD163), Merkel cell polyomavirus-specific polymerase chain reaction, and coanalysis with clinical and histologic data.

RESULTS

We found a more than 3-fold increase in the mean density of absolute numbers of small lymphatic capillaries (diameter <10 μm) and a more than 8-fold increase in the median ratio of the number of small to large lymphatics (<10/≥10 μm) paratumorally compared with intraindividual controls. VEGF-C(+)CD68(+) CD163(+) cells (interpreted as M2 macrophages) could be identified as an important potentially lymphangiogenesis-inducing cell type.

LIMITATIONS

Partially lacking follow-up data limited the analysis of the prognostic impact.

CONCLUSIONS

Our findings strongly indicate lymphangiogenesis in MCC driven by VEGF-C(+)CD68(+) CD163(+) M2 macrophages.

D2-40, Podoplanin, and CD31 as a Prognostic Predictor in Invasive Ductal Carcinomas of the Breast

PURPOSE

Distant metastasis and recurrence are major prognostic factors associated with breast cancer. Both lymphovascular invasion (LVI) and blood vessel invasion (BVI) are important routes for metastasis to regional lymph nodes and for systemic metastasis. Despite the importance of vascular invasion as a prognostic factor, application of vascular invasion as a histopathological criterion is controversial. The aim of this study was to distinguish LVI from BVI in prognosis and recurrence of breast cancer using an endothelial subtype specific immunohistochemical stain (podoplanin, D2-40, and CD31).

METHODS

Sections from 80 paraffin-embedded archival specimens of invasive breast cancer were stained for podoplanin, D2-40, or CD31 expression. Immunohistochemical staining results were correlated with clinicopathological features, such as tumor size, status of lymph node metastases, estrogen receptor status, progesterone receptor status, human epidermal growth factor receptor-2 expression, and recurrence. Patients with ductal carcinoma in situ and stage IV breast cancer were excluded.

RESULTS

A significant correlation was found between D2-40 LVI positivity and lymph node metastasis (p=0.022). We found a significant correlation between D2-40 LVI positivity and recurrence of breast cancer (p=0.014). However, no significant correlation was found between BVI and recurrence. A poorer disease free survival was shown for D2-40 positive LVI (p=0.003). In a multivariate analysis, the presence of D2-40 LVI positivity revealed a significant association with decreased disease-free survival.

CONCLUSION

D2-40 LVI positivity was a more prognostic predictor of breast cancer than BVI.

Best practices in diagnostic immunohistochemistry: myoepithelial markers in breast pathology

CONTEXT

Numerous immunohistochemical stains have been shown to exhibit exclusive or preferential positivity in breast myoepithelial cells relative to their luminal/epithelial counterparts. These myoepithelial markers provide invaluable assistance in accurately classifying breast proliferations, especially in core biopsies. Although numerous myoepithelial markers are available, they differ in their sensitivity, specificity, and ease of interpretation, which may be attributed, to a large extent, to the variable immunoreactivity of these markers in stromal cells including myofibroblasts, vessels, luminal/epithelial cells, and tumor cells.

OBJECTIVE

To review commonly used myoepithelial markers in breast pathology and a selection of diagnostic scenarios where they may be useful.

DATA SOURCES

The information outlined in this review article is based on our experiences with routine cases and a review of English-language articles published between 1987 and 2008.

CONCLUSIONS

To demonstrate the presence or absence of myoepithelial cells, a panel-based approach of 2 or more markers is recommended. Markers that most effectively combine sensitivity, specificity, and ease of interpretation include smooth muscle myosin heavy chains, calponin, p75, p63, P-cadherin, basal cytokeratins, maspin, and CD10. These markers, however, display varying cross-reactivity patterns and variably reduced expression in the myoepithelial cells bordering in situ carcinomas. The choice of a myoepithelial marker should be dependent on a combination of factors, including published evidence on its diagnostic utility, its availability, performance characteristics that have been achieved in a given laboratory, and the specific diagnostic scenario. When its use is deemed necessary, immunohistochemistry for myoepithelial cells in breast pathology is most effective when conceptualized as supplemental, rather than central to routine morphologic interpretation.

D2-40/p63 defined lymph vessel invasion has additional prognostic value in highly proliferating operable node negative breast cancer patients

Phosphohistone H3 assessed proliferation has strong prognostic value. Lymph vessel invasion by D2-40 is also prognostic, but D2-40+ myoepithelial expression in small ducts completely filled by solid-pattern ductal carcinoma in situ can mimic lymphovascular invasion. As myoepithelial cells are also p63 positive, we have investigated whether lymph vessel invasion identified by combined D2-40/p63 is stronger prognostically than by D2-40 alone, and whether it has independent prognostic value to phosphohistone H3. In 240 operable T(1-2)N(0)M(0) node negative invasive breast cancer patients <71 years, phosphohistone H3 was determined by quantitative immunohistochemistry and lymph vessel invasion by D2-40/p63 double immunostaining. Correlation analysis between the clinico-pathologic factors and lymph vessel invasion, and univariate and multivariate prognostic survival analysis were performed. With median 117 (range: 12-192) months follow-up, 36 patients (15%) developed and 28 (12%) died of distant metastases. Ten of the 61 patients (16%) with cancer cells surrounded by D2-40 were p63 positive and none of these 'false lymph vessel invasion' recurred. D2-40+/p63- lymph vessel invasion occurred in 51/239 (21%) cases and correlated with grade, mitotic activity index, phosphohistone H3, ER, cytokeratin14, and HER2. D2-40+/p63- lymph vessel invasion was strongly prognostic, but far more in women ≥55 than those <55 years (P<0.0001 and 0.04). With multivariate analysis, phosphohistone H3 proliferation was the strongest single prognosticator. Lymph vessel invasion had additional prognostic value to phosphohistone H3 only in women ≥55. This group of patients, without/with lymph vessel invasion, had 10-year survival rates of 83 and 50%, respectively (hazard ratio-lymph vessel invasion=3.0, P=0.04; hazard ratio-phosphohistone H3=6.9, P=0.002). Where age was <55 years, only phosphohistone H3 had independent prognostic value. Combinations of other features had no additional value. In conclusion, T(1-2)N(0)M(0) invasive breast cancer patients ≥55 years with phosphohistone H3≥13, D2-40+/p63- defined lymph vessel invasion identifies a subgroup with a high risk of distant metastases.

Objective assessment of lymphatic and blood vascular invasion in lymph node-negative breast carcinoma: findings from a large case series with long-term follow-up

In a previous study on a small series of breast cancers, we developed objective methods for the assessment of vascular invasion (VI), using immunohistochemical staining. We found that VI was predominantly lymphovascular invasion (LVI), with minimal contribution of blood vascular invasion (BVI). The aims of the current study were: (a) to assess the frequency, extent and prognostic role of LVI and BVI in a large, well-characterized series of LN-negative breast cancers; and (b) to assess the ability of VI to stratify early breast cancer into different prognostic groups. Paraffin-embedded sections from 1005 lymph-node (LN)-negative primary invasive breast cancers were stained for CD34, CD31 and podoplanin/D240 to detect BVI and LVI. VI lesions were assessed and the results were correlated with clinicopathological criteria and survival. VI was detected in 218 (22%); 211/218 (97%) were LVI, while BVI was detected in 7/218 (3%). The frequency of LVIs/section ranged from 1 to 79, with no significant difference between the frequency of LVI and outcome. The presence of LVI was significantly associated with adverse disease-free interval (DFI) and poor overall survival (OS) in both univariate and multivariate analyses. The results from the study indicated that VI in early stage breast cancer is predominantly LVI and that its objective assessment is a powerful independent prognostic factor. Efforts to detect early metastatic activity, such as diligent pathological examination of sentinel LN biopsies would be complimented by the objective evaluation of VI status of the primary tumour. VI status should be included routinely in breast cancer staging systems.

Epithelial displacement into the lymphovascular space can be seen in breast core needle biopsy specimens

Breast core needle biopsy (BCNB) has been reported to cause mechanical epithelial displacement into adjacent tissues, leading to diagnostic difficulties. However, epithelial displacement into lymphovascular spaces (EDLS), mimicking true lymphovascular invasion, may also be seen in the initial BCNB specimen itself. We retrospectively reviewed 218 BCNB specimens diagnosed as ductal carcinoma in situ (DCIS) and searched for the presence of EDLS. The subsequent surgically resected specimens for all cases were also reviewed. EDLS was demonstrated in 7 (3.2%) of 218 initial BCNB specimens. It could be differentiated from detached clusters of DCIS cells within preexisting ducts by morphologic features and immunohistochemical stains for D2-40 and p63. EDLS can occur at initial BCNB, and, therefore, the presence of tumor cell clusters within lymphovascular spaces in a BCNB specimen with DCIS may not represent true lymphovascular invasion.

D2-40, a novel immunohistochemical marker in differentiating dermatofibroma from dermatofibrosarcoma protuberans

The distinction between dermatofibroma, particularly cellular variant, and dermatofibrosarcoma protuberans in excisional biopsies is usually straightforward. However, a separation between the two may be sometimes challenging, especially in superficial biopsies. Although factor XIIIa and CD34 immunostains are useful in differentiating dermatofibroma and dermatofibrosarcoma protuberans in most instances, focal CD34 positivity may be seen in cellular fibrous histiocytoma. Some cases reveal overlapping immunostain results. D2-40 identifies a 40-kDa O-linked sialoglycoprotein present on a variety of tissues including testicular germ cell tumors as well as lymphatic endothelium. In this study, we investigated the utility of D2-40 in separating dermatofibroma from dermatofibrosarcoma protuberans and compared the results with other commonly used immunostains. Fifty-six cases of dermatofibroma (including six cellular variant) and 29 cases of dermatofibrosarcoma protuberans were retrieved from the archives of Department of Anatomic Pathology at Sunnybrook Health Sciences Center in University of Toronto. We applied factor XIIIa, CD34, and monoclonal mouse anti-D2-40 immunostains to formalin-fixed, paraffin-embedded tissue sections. All 56 (100%) cases of dermatofibroma demonstrated strong and diffuse immunoreactivity to D2-40 in the spindle cells and stroma. Similarly, factor XIIIa showed strong and diffuse positivity in the spindle cells. Nearly all dermatofibromas were negative for CD34 except one case revealing focal positivity. None of dermatofibrosarcoma protuberans cases were labeled by D2-40, although four cases showed weak and patchy background staining in contrary to diffuse, strong, and crisp staining seen in dermatofibromas. Our results indicate that D2-40 seems to be a sensitive immunohistochemical marker for dermatofibromas, including cellular variant. Focal and faint D2-40 staining may be seen in the stroma of dermatofibrosarcoma protuberans. Our findings suggest that D2-40 can be used as a complementary immunostain to factor XIIIa and CD34 in problematic and challenging cases on superficial biopsies.

Vascular invasion in breast cancer; an overview of recent prognostic developments and molecular pathophysiological mechanisms

Vascular invasion (VI) is an essential step in breast cancer metastasis and the main cause of morbidity and mortality from the disease. Detection of VI in the primary tumour is a marker of metastatic potential. The prognostic value of VI in breast cancer has been known for more than four decades, but its application in clinical practice is still fraught with difficulties due to the limited number of studies conducted on large numbers of well-characterized patients with long-term follow-up. Detection of VI in the primary tumour is currently assessed using sections stained with haematoxylin and eosin, which has some disadvantages. A number of vascular markers have been used to improve detection of VI; however, their sensitivity and specificity, as endothelial markers, vary considerably. In this review we describe the evolution of the prognostic importance of VI and the recent pathomolecular mechanisms that contribute to the ability of breast cancers to invade through vessels, in addition to the types, locations and methods of detection of vascular invasion.

Use of Myoepithelial Cell Markers in the Differential Diagnosis of Benign, In situ, and Invasive Lesions of the Breast

Immunohistochemical markers for myoepithelial cells are commonly used to distinguish invasive from noninvasive lesions in the breast. The approach takes advantage of the fact that conventional invasive carcinomas lack surrounding myoepithelial cells, whereas nearly all benign lesions and in situ carcinomas retain their myoepithelial cell layer. Although conceptually straightforward, the interpretation of myoepithelial cell markers can be complicated by misleading patterns of reactivity (such as stromal or tumor cell staining) or lack of reactivity (due to reduced numbers of myoepithelial cells or variable antigenicity). In this article, we discuss the advantages and disadvantages of commonly used myoepithelial cell markers, their general utility in distinguishing invasive from noninvasive processes, and pitfalls in their interpretation. We also examine whether the detection of myoepithelial cells is helpful in the evaluation of papillary lesions, another common application. Myoepithelial cell markers can be diagnostically useful in the distinction of many benign, in situ, and invasive lesions, but they must be interpreted in conjunction with careful morphologic analysis.

Immunostaining with D2-40 improves evaluation of lymphovascular invasion, but may not predict sentinel lymph node status in early breast cancer

Background

Sentinel lymph node (SLN) biopsy is a widely used diagnostic procedure in the management of early breast cancer. When SLN is free of metastasis, complete axillary dissection may be skipped for staging in clinically N0 patients, allowing a more conservative procedure. Histological tumor features that could reliably predict SLN status have not yet been established. Since the degree of tumor lymphangiogenesis and vascularization may theoretically be related to the risk of lymph node metastasis, we sought to evaluate the relationship between lymph vessel invasion (LVI), lymphatic microvascular density (LVD), microvascular density (MVD) and VEGF-A expression, with SLN status and other known adverse clinical risk factors.

Methods

Protein expression of D2–40, CD34, and VEGF-A was assessed by immunohistochemistry on paraffin-embedded sections of primary breast cancer specimens from 92 patients submitted to SLN investigation. The presence of LVI, the highest number of micro vessels stained for D2–40 and CD34, and the protein expression of VEGF-A were compared to SLN status, clinicopathological features and risk groups.

Results

LVI was detected in higher ratios by immunostaining with D2–40 (p < 0.0001), what would have changed the risk category from low to intermediate in four cases (4.3%). There was no association between LVI and other angiogenic parameters determined by immunohistochemistry with SLN macrometastases, clinical features or risk categories.

Conclusion

Assessment of LVI in breast carcinoma may be significantly increased by immunostaining with D2–40, but the clinical relevance of altering the risk category using this parameter may not be advocated according to our results, neither can the use of LVI and LVD as predictors of SLN macrometastasis in early breast cancer.

Pure and predominantly pure intralymphatic breast carcinoma after neoadjuvant chemotherapy: an unusual and adverse pattern of residual disease

Neoadjuvant chemotherapy is standard of care for patients with locally advanced breast cancer. Patients who achieve a pathologic complete response have a more favorable outcome than those who do not; however, a standard system for classifying residual disease has not been adopted. Various definitions of complete response exist, some of which allow for minimal residual invasive or in situ carcinoma. The pattern of residual carcinoma restricted to lymphatic spaces without stromal invasion, herein called pure intralymphatic carcinoma, has not been well addressed. Neither has the pattern of minimal residual stromal invasive cancer accompanied by an extensive intralymphatic component, herein called predominantly pure intralymphatic carcinoma. We report the incidence, clinicopathologic features, and clinical significance of pure and predominantly pure intralymphatic carcinoma in a cohort of 146 neoadjuvant-treated breast cancer patients. We also evaluate the use of the immunohistochemical lymphatic marker D2-40 in these tissues exposed to neoadjuvant chemotherapy. Six patients (4%) had residual pure intralymphatic carcinoma. No gross abnormalities were present in the mastectomy specimens except for 1 case that had a discrete mass, corresponding to residual in situ carcinoma. Residual intralymphatic tumor size ranged from 0.2 to 6 cm. All but one had residual positive lymph nodes. Residual predominantly pure intralymphatic carcinoma was found in 5/146 (4%) patients. A discrete gross mass was observed in 3/5 specimens. Whereas residual stromal invasive carcinoma ranged in size from 0.1 to 1.8 cm, the intralymphatic component ranged from 6 to 9.3 cm. All had residual positive lymph nodes. D2-40 adequately marked lymphatic endothelium in all cases tested. Death occurred in 6/11 (55%) versus 17/135 (13%) patients with or without pure/predominantly pure intralymphatic carcinoma, respectively. After controlling for tumor stage, the presence of either of these residual intralymphatic patterns was associated with a 3-fold increase in death (Cox proportional hazards ratio=3.59, 95% confidence interval, 1.29, 9.99, P=0.014). Elevated risk for disease progression was also observed but this was not statistically significant. We conclude that pure/predominantly pure intralymphatic carcinoma is a clinically significant pattern of residual disease. This may be an underrecognized pattern because of the discordance between gross and microscopic findings and because of challenges in diagnosing intralymphatic carcinoma. D2-40 immunostaining is useful in this setting. Current staging criteria should be clarified to define whether extensive intralymphatic tumor should be incorporated in tumor stage assignment.

D2-40 immunohistochemistry--so far!

D2-40 is a commercially available monoclonal antibody directed against human podoplanin, a transmembrane mucoprotein that is expressed in lymphatic endothelial cells. Since its introduction, D2-40 immunoexpression has been described in a variety of lymphovascular neoplasms including lymphangioma, Kaposi sarcoma, and hemangioendothelioma, as well as nonvascular neoplasms such as epithelioid mesothelioma, seminoma, and hemangioblastoma. More recently, D2-40 immunoexpression has been reported in primary adrenal cortical tumors, schwannomas, and adnexal tumors of the skin. This brief review provides an update on the ever-expanding proposed applications of D2-40 immunohistochemistry in surgical pathology.