Fibroepithelial lesions; The WHO spectrum.

Fibroepithelial lesions of the breast comprise a morphologically and biologically heterogeneous group of biphasic tumors with epithelial and stromal components that demonstrate widely variable clinical behavior. Fibroadenomas are common benign tumors with a number of histologic variants, most of which pose no diagnostic challenge. Cellular and juvenile fibroadenomas can have overlapping features with phyllodes tumors and should be recognized. Phyllodes tumors constitute a spectrum of lesions with varying clinical behavior and are graded as benign, borderline or malignant based on a set of histologic features according to recommendations by the World Health Organization (WHO). Recent developments have significantly expanded our understanding of the pathogenesis of fibroepithelial lesions, highlighting fibroadenomas as true neoplasms and underscoring a commonality with phyllodes tumors in the form of recurrent MED12 exon 2 mutations. In addition, sequencing studies have elucidated pathways associated with phyllodes tumor progression. Accurate diagnosis and grading of phyllodes tumors are important for patient management and prognosis, as grade broadly correlates with increasing local recurrence risk, and essentially only malignant tumors metastasize. However, classification of fibroepithelial lesions in many cases remains challenging on both core biopsy and excision specimens. A commonly encountered problem at the benign end of the spectrum is the distinction of benign phyllodes tumor from cellular fibroadenoma, which is largely due to the subjective nature of histologic features used in diagnosis and histologic overlap between lesions. Grading is further complicated by the requirement to integrate multiple subjective and ill-defined parameters. On the opposite end of the histologic spectrum, malignant phyllodes tumors must be distinguished from more common metaplastic carcinomas and from primary or metastatic sarcomas, which can be especially difficult in core biopsies. Immunohistochemistry can be useful in the differential diagnosis but should be interpreted with attention to caveats. This review provides an overview and update on the spectrum of fibroepithelial lesions, with special emphasis on common problems and practical issues in diagnosis.

Survivin in breast lesions: immunohistochemical analysis of 196 cases.

We examined the survivin expression pattern by immunohistochemistry in 43 fibroadenomas and 153 ductal carcinomas of the breast. The subcellular localization of survivin and the intensity of immunoreaction were assessed. We analyzed the differences of survivin expression between fibroadenomas and carcinomas. We also correlated the survivin expression pattern in carcinomas with other clinicomorphological parameters such as the age of patients, the grade and size of primary tumor as well as the lymph node metastasis. Overall, survivin was detected in 107/153 carcinomas (69.9%) and in 26/43 fibroadenomas (60.5%). Statistical analysis confirmed significant correlations between the assessed parameters in fibroadenomas and carcinomas. Grade of carcinomas was significantly related to survivin expression in both subcellular localization and the intensity of immunoreaction. Tumor grade 3 was associated with nuclear positivity and combined nuclear and cytoplasmic localization. Carcinomas larger than 20 mm showed nuclear and combined localization in 81% of cases and higher intensity of survivin immunoreaction was also notably related to larger carcinomas. Statistically significant differences were also observed between subcellular survivin localization and intensity of immunoreaction. Our result suggest that nuclear accumulation of survivin is associated with proliferative fenotype and survivin was shown to be a worse prognostic marker in breast ductal carcinoma.

Collagen type III α1 as a useful diagnostic immunohistochemical marker for fibroepithelial lesions of the breast.

Phyllodes tumors (PTs) of the breast constitute an uncommon group of fibroepithelial neoplasms that are classified into benign, borderline, and malignant categories based on a constellation of histologic characteristics including cytologic atypia, mitotic count, degree of stromal cellularity, stromal overgrowth, and microscopic margins. Accurately and reproducibly differentiating these tumors is a long-standing diagnostic challenge. In addition, the distinction between benign PT from cellular fibroadenoma (FA) is especially difficult because of overlapping microscopic features. We have previously shown differential expression of various collagens, including collagen type III α1 (Col3A) in breast carcinomas. In this study, we evaluated clinicopathological characteristics of 95 cases of fibroepithelial lesions including 56 PTs and 39 FAs (25 cellular FA, 14 typical FA) and correlated them with the immunohistochemical staining pattern for Col3A. We found that stromal Col3A expression was significantly increased in PTs when compared with FAs (P < .0001). Among the PT groups, there was significantly increased expression from benign tumors through borderline to malignant tumors. High Col3A expression was associated with PT type, irregular margin status, and high mitotic activity. A distinct periductal cuffing pattern of Col3A staining was unique to PTs and absent in FAs. These findings suggest that Col3A can be a potential adjunct marker for both differentiating FA from PT and assessing malignant potential in PTs.

Low-grade myofibroblastic sarcoma arising in fibroadenoma of the breast-A case report.

BACKGROUND: Myofibroblastic sarcoma or myofibrosarcoma is a malignant tumor of myofibroblasts and known to develop rarely in the breast, but its underlying lesion and tumor cell origin have never been reported yet. CASE PRESENTATION: A 61-year-old female presented with a gradually growing breast mass with well-demarcated ovoid nodular shape. The tumor was histologically characterized by fascicular-growing spindle cell proliferation with large areas of hyalinized fibrosis and focally ductal epithelial remnants embedded in myxoid stroma, mimicking a fibroadenomatous lesion. It had frequent mitoses of 5-16/10 high-power fields, hemorrhagic necrosis, and focally pericapsular invasion. The spindle cells were diffusely immunoreactive for fibronectin, smooth muscle actin, and calponin, which suggest a myofibroblastic origin. Multiple irregularly thickened vessels with medial or pericytic cell proliferation were found to be merged with the intrinsic tumor cells. The tumor could be diagnosed low-grade myofibroblastic sarcoma arising in an old fibroadenoma. CONCLUSION: We report a case of a low-grade mammary myofibrosarcoma that showed a background lesion of fibroadenoma first in the worldwide literature and suggest the pericytes or medial muscle cells of the intratumoral vessels as the cell origin of the myofibroblastic sarcoma.

Significance of TLR4/MyD88 expression in breast cancer.

OBJECTIVE: To investigate the expression of TLR4/MyD88 in breast cancer, and explore the relationship between their expression and breast cancer tumor growth and invasion. METHODS: We examined the protein expression of TLR4 and MyD88 in 60 cases of histologically confirmed breast cancer. The relationship of their protein expressions with clinical features including age at diagnosis, tumor size and stage, lymph node metastasis and distant metastasis were analyzed. RESULTS: The IHC results showed that TLR4 and MyD88 were expressed in 63.3% (38/60) and 58.3% (35/60) of malignant breast tumors respectively. TLR4 expression in breast cancer were significantly higher than in fibroadenoma (n = 4, 20.0%) and adjacent normal tissues (n = 2, 10.0%) (P < 0.001). MyD88 expression in breast cancer were also significantly higher than in fibroadenoma (n = 4, 20.0%) and adjacent normal tissue (n = 3, 15.0%) (P < 0.001). The gene expressions of TLR4 and MyD88 were significantly higher in breast cancer than in fibroadenoma and adjacent normal tissues (P < 0.05). The protein expressions of TLR4 and MyD88 were also significantly associated with poor clinical features (P < 0.05). CONCLUSION: TLR4 and MyD88 expression might be associated with breast cancer growth and regional and distant metastases.

Nuclear localization of MUC1 extracellular domain in breast, head and neck, and colon cancer.

BACKGROUND: The glycoprotein MUC1 is overexpressed and underglycosylated in cancer cells. MUC1 is translated as a single polypeptide that undergoes autocleavage into 2 subunits (the extracellular domain and the cytoplasmic tail), and forms a stable heterodimer at the apical membrane of normal epithelial cells. The MUC1 cytoplasmic tail localizes to the cytoplasm of transformed cells and is targeted to the nucleus. AIMS: To study the expression of the MUC1 extracellular subunit in cell nuclei of neoplastic breast, head and neck, and colon samples. MATERIALS AND METHODS: 330 primary tumor samples were analyzed: 166 invasive breast carcinomas, 127 head and neck tumors, and 47 colon tumors; 10 benign breast disease (BBD) and 40 normal specimens were also included. A standard immunohistochemical method with antigen retrieval was performed. Nuclear fractions from tissue homogenates and breast cancer cell lines (ZR-75, MDA-MB-231, MCF7, and T47D) were obtained and analyzed by Western blotting (WB). The anti-MUC1 extracellular subunit monoclonal antibody HMFG1 was used for immunohistochemistry. RESULTS: 37/166 breast cancer specimens, 5/127 head and neck cancer specimens, 2/47 colon cancer samples, and 3/10 BBD samples showed immunohistochemical staining at the nuclear level. No nuclear reaction was detected in normal samples. By WB, breast and colon cancer purified nuclear fractions showed reactivity at 200 kDa in 3/30 breast and 3/20 colon cancer samples as well as purified nuclear fractions obtained from breast cancer cell lines. CONCLUSIONS: This study shows that the MUC1 extracellular domain might be translocated to the cell nucleus in breast, head and neck, and colon cancer as well as BBD.

Multicentric study on ¹8F-FDG-PET/CT breast incidental uptake in patients studied for non-breast malignant purposes.

AIM: Our study has aimed to establish the prevalence and pathological nature of fluorine-18-fluorodeoxyglucose ((18)F-FDG) breast incidental uptake (BIU) in patients studied for non-malignant breast tumours and then to compare our data obtained in three Italian nuclear medicine centres with those available in literature. MATERIAL AND METHODS: We retrospectively evaluated 42,927 (18)F-FDG-PET/CT scans performed on patients studied in three Italian Nuclear Medicine Centres. All patients underwent (18)F-FDG-PET/CT for oncologic purposes not related to breast disease. RESULTS: Among 42,927 scans, a BIU was identified in 79 (0.18%) patients, 75 (95%) female and 4 (5%) male with an average age of 62 ± 17 years. Twenty-five out of 35 (71.5%) BIUs were malignant and 10/35 (28.5%) benign. Among the 25/35 incidentalomas that were malignant, 12/25 (48%) were infiltrating ductal carcinoma, 5/25 (20%) ductal carcinoma (infiltrating and in situ), 4/25 (16%) lobular carcinoma, 2/25 (8%) ductal carcinoma in situ and 2/25 (8%) were metastases from the primary tumour under investigation. Of the 10 BIUs that were benign in the histological examination, after further investigations it was found that 9/10 (90%) were fibroadenomas and 1/10 (10%) was a benign lesion not better specified. The lesion to liver or to blood-pool SUVmax ratio in malignant lesions is significantly higher than in benign ones. CONCLUSIONS: Our multicenter study demonstrates that, although they are uncommon, BIUs show a high percentage of malignancy and therefore requires further research.

Role of Sphk1 in the malignant transformation of breast epithelial cells and breast cancer progression.

BACKGROUND: The ojective of the following study is to investigate the role of sphingosine kinase 1 (Sphk1) in the malignant transformation of breast epithelial cells and breast cancer progression and its mechanism. MATERIALS AND METHODS: Immunohistochemistry was performed to detect Sphk1 and E-cadherin (E-cad) in resected breast samples. Sphk1 was transfected in normal human breast epithelial cell line (MCF-10A) by Lentivirus and silenced in breast cancer cell line (MCF-7) using small interfering ribonucleic acid. The effect of tumor necrosis factor alpha (TNF-α) and/or N, N-dimethylsphingosine (DMS) on the Sphk1 and E-cad expression, MCF-10A cell proliferation and invasion was investigated. Real time-polymerase chain reaction and western-blot was used to detect messenger ribonucleic acid and protein. Cell counting kit-8 and transwell were used to measure cell proliferation and invasion. RESULTS: Sphk1 was positive expression in 114 breast tumors (75.50%) but negative in fibroadenomas. The expression of E-cad and Sphk1 were negatively correlated and E-cad (-)/Sphk1 (+) carriers showed higher ratio of axillary lymph node metastasis than E-cad (+)/Sphk1 (-) carriers. Overexpression of Sphk1 in MCF-10A reduced E-cad expression and improved cell proliferation and invasion, but knockdown of Sphk1 in MCF-7 decreased cell proliferation and invasion. TNF-α increased Sphk1 expression, enhanced the ability of Sphk1 in decreasing E-cad expression, which could be blocked by DMS. TNF-α promoted MCF-10A cell proliferation and invasion. CONCLUSION: Sphk1 plays an important role in the malignant transformation of breast epithelial cells and modulates breast cancer metastasis through the regulation of E-cad expression. TNF-α can up-regulate Sphk1 expression and reduce E-cad expression through Sphk1, which can be blocked by DMS. TNF-α/Sphk1/E-cad pathway may be a newly discovered pathway and plays an important role in tumorigenesis and metastasis.

Expression of growth hormone and growth hormone receptor in fibroadenomas of the breast.

Fibroadenoma is the most prevalent benign breast tumor. It consists of epithelial and stromal components. In general, breast tumors are highly hormonally dependent and growth hormone by its physiology may have a possible oncogenic potential. Therefore, the aim of this study was to determine the expression of growth hormone and growth hormone receptor in epithelial and stromal components of fibroadenomas. Study group included 30 randomly chosen fibroadenomas from female patients aged between 18 and 69 years. The expression of growth hormone and growth hormone receptor was defined in both histologic components of fibroadenomas. Growth hormone was expressed in 96.7% of both epithelial and stromal components of fibroadenomas, with stronger expression in the stromal component. The same percentage of positive reaction (96.7%) was obtained in the epithelial component of fibroadenomas for growth hormone receptor expression. Only 6.7% of stromal components tested for growth hormone receptor were positive. The high expression of growth hormone and growth hormone receptor in fibroadenoma tissue indicates their possible role in the pathogenesis of this tumor. Follow up of patients with high expression of growth hormone and growth hormone receptor may be suggested.

Lipofibroadenoma of the thymus: a case report.

We observed an unusual case of Lipofibroadenoma (LFA) in the anterior mediastinum with a 21-year-old man, who was detected with a mass on a chest X-ray scan for one month. Thymothymectomy was then performed and the mass was excised completely, in which the tumor was histologically composed of epithelial cells, lymphocytes, mature adipose and fibrous tissue. Within the tumor, the fat cells was distributed singly or multifocally under the ground of fibro tissue with hyaline degeneration, and the epithelial cells were arranged as crack structure with lymphocytes infiltrated sparsely. By immunohistochemical staining assay, the epithelial cells were positive for AE1/AE3 and CK19, and the lymphocytes were CD3 and CD20 positive. Based on the histological characters, a diagnosis of LFA was made, and the total follow-up period was determined to be forty six months. The final repeated CT scan revealed no recurring or residual lesions were detected during the post-surgical course. VIRTUAL SLIDE: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1500429801911703.

Infarcted fibroadenoma of the breast: report of two new cases with review of the literature.

INTRODUCTION: Fibroadenomas are the most common benign breast tumors in young women. Infarction is rarely observed in fibroadenomas and when present, it is usually associated with pregnancy or lactation. Infarction can exceptionally occur as a complication of previous fine-needle aspiration biopsy or during lactation and pregnancy. MATERIALS AND METHODS: Retrospective review of 650 cases of fibroadenomas diagnosed at our institution during the 8-years period identified two cases of fibroadenomas with infarction (rate ~0.3%). RESULTS: Two partially infarcted fibroadenomas were diagnosed on core biopsy and frozen section in an adolescent girl (13 years old) and in a young woman (25 years old), respectively. No preceding fine-needle aspiration biopsy was performed in these cases, nor were the patients pregnant or lactating at the time of the diagnosis. CONCLUSION: Spontaneous infarction within fibroadenoma is a rare phenomenon in younger patients. The presence of necrosis on core biopsy or frozen section should be cautiously interpreted and is not a sign of malignancy. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1556060549847356.

Techniques and evaluation from a cross-platform imaging comparison of quantitative ultrasound parameters in an in vivo rodent fibroadenoma model.

This contribution demonstrates that quantitative ultrasound (QUS) capabilities are platform independent, using an in vivo model. Frequency-dependent attenuation estimates, backscatter coefficient, and effective scatterer diameter estimates are shown to be comparable across four different ultrasound imaging systems with varied processing techniques. The backscatter coefficient (BSC) is a fundamental material property from which several QUS parameters are estimated; therefore, consistent BSC estimates among different systems must be demonstrated. This study is an intercomparison of BSC estimates acquired by three research groups (UIUC, UW, ISU) from four in vivo spontaneous rat mammary fibroadenomas using three clinical array systems and a single-element laboratory scanner system. Because of their highly variable backscatter properties, fibroadenomas provided an extreme test case for BSC analysis, and the comparison is across systems for each tumor, not across the highly heterogeneous tumors. RF echo data spanning the 1 to 12 MHz frequency range were acquired in three dimensions from all animals using each system. Each research group processed their RF data independently, and the resulting attenuation, BSC, and effective scatterer diameter (ESD) estimates were compared. The attenuation estimates across all systems showed the same trends and consistently fit the power-law dependence on frequency. BSCs varied among the multiple slices of data acquired by each transducer, with variations between transducers being of a similar magnitude as those from slice to slice. Variation between BSC estimates was assessed via functional signal-to-noise ratios derived from backscatter data. These functional signal-to-noise ratios indicated that BSC versus frequency variations between systems ranged from negligible compared with the noise level to roughly twice the noise level. The corresponding functional analysis of variance (fANOVA) indicated statistically significant differences between BSC curves from different systems. However, root mean squared difference errors of the BSC values (in decibels) between different transducers and imaging platforms were less than half of the BSC magnitudes in most cases. Statistical comparison of the effective scatterer diameter (ESD) estimates resulted in no significant differences in estimates from three of the four transducers used for those estimates, demonstrating agreement among estimates based on the BSC. This technical advance demonstrates that these in vivo measurements can be made in a system-independent manner; the necessary step toward clinical implementation of the technology.

Elevated expression of USP22 in correlation with poor prognosis in patients with invasive breast cancer.

PURPOSE: Ubiquitin-specific protease 22 (USP22), a novel deubiquitinating enzyme, has been associated with metastasis, therapy resistance, and cell-cycle progression. The purpose of this study was to investigate the expression level of USP22 in breast samples and to evaluate its clinical significance in breast cancer patients. METHODS: Immunohistochemistry was used to determine the expression of USP22 protein in 31 breast fibroadenoma and 100 breast cancer patients in comparison with 34 normal breast specimens. Furthermore, we analyzed the correlation between the expression of the USP22 protein and various clinicopathologic factors including survival status of patients with breast cancer. RESULTS: The immunohistochemistry results showed that the expression level of USP22 protein in breast cancer samples was significantly higher than that in breast fibroadenoma and normal breast tissues (P = 0.003 and P = 0.021). Moreover, statistical analysis showed that high USP22 expression was positively related to lymph node metastasis, Her-2, Ki67, and recurrence. Furthermore, it was shown that patients with high USP22 expression had significantly poorer outcome compared with patients with low expression of USP22 for patients with positive lymph nodes. Multivariate Cox regression analysis revealed that USP22 expression level was an independent prognostic factor for both overall survival and disease-free survival (P = 0.039 and P = 0.041, respectively). CONCLUSION: Overexpression of USP22 may contribute to the progression of breast cancer and thus may serve as a new molecular marker to predict the prognosis of breast cancer patients.

Diagnostic potential of Stokes Shift spectroscopy of breast and prostate tissues-- a preliminary pilot study.

Stokes Shift (SS) Spectroscopy (SSS) of normal and abnormal breast and prostate tissues were studied. SS spectra is measured by simultaneously scanning both the excitation and emission wavelengths while keeping a fixed wavelength interval of Δλ = 20 nm. Characteristic, highly resolved peaks and significant spectral differences between normal and different pathological tissues of breast and prostate tissues were observed. The SS spectra of normal and different pathological breast and prostate tissues show the distinct peaks around 300, 350, 450, 500 and 600 nm may be attributed to tryptophan, collagen, NADH, flavin and porphyrin, respectively. Results of the current study demonstrate that the SS spectral changes due to tryptophan, collagen, hemoglobin, NADH, FAD and porphyrin have good diagnostic potential; therefore can be targeted as native tumor markers.

Recurrent challenges in the evaluation of fibroepithelial lesions.

CONTEXT: The morphologic spectrum of mammary fibroepithelial lesions ranges from fibroadenoma, a common benign neoplasm, to phyllodes tumor, an uncommon lesion that can sometimes recur and metastasize. OBJECTIVE: To focus on problems encountered in the diagnostic evaluation of fibroepithelial tumors, highlighting the diagnostically relevant morphologic features and providing an update on the immunohistochemical profile and genetic alterations of these rare neoplasms. DATA SOURCES: A PubMed search of the English-language literature identified published reports on fibroepithelial lesions, with a special focus on phyllodes tumor. The results and conclusions of these studies form the basis of this review. CONCLUSIONS: The distinction between fibroadenoma and phyllodes tumor is usually not problematic, especially in excision specimens. In some cases, however, the diagnostic evaluation of fibroepithelial lesions can be challenging, especially if only limited material is available. Morphologic predictors of local recurrence of phyllodes tumor include cellularity and cytologic atypia, mitotic activity, positive margins, infiltrative borders, fibroproliferative satellite nodules, and past history of fibroadenoma. Predictors of distant metastasis include size, tumor necrosis, and stromal overgrowth. None of these parameters, however, constitutes a definite marker of malignancy. Presently, molecular and immunohistochemical techniques play a limited role in the diagnosis of fibroepithelial lesions.

Fibroadenoma of the gallbladder with borderline malignancy: a poorly recognized gallbladder tumor.

Fibroadenoma of the gallbladder is extremely rare tumor, with only two cases reported in the world. It is characterized by abundant loose edematous connective tissue, glandular structure, polypoid structure covered by epithelia, and a filamentous pedicle. We report a case of 78-year-old woman histopathologically diagnosed after surgery. Macroscopically, the tumor was a dark-greenish solid mass with a short stalk, filling the gallbladder cavity, and it measured 11.5 x 4.0 x 3.5 cm in diameter. Microscopically, the tumor was composed of abundant loose stroma and a glandular component. Some of the glandular cells had hyperchromatic nuclei with disturbed polarity and were positively stained by p53 (30%) and Ki-67 (30-40%). Part of the stromal component revealed hypercellularity with an irregular nucleus, mitosis (2-3 cells/10 high-power fields), and positivity for Ki-67 (20%) and p53 (50%). We diagnosed this peculiar tumor as "fibroadenoma of the gallbladder with borderline malignancy". We present the details of this extremely rare case and discuss the pathological findings, comparing them to those in the two previously reported cases and to carcinosarcoma of gallbladder.

Mean nuclear area and metallothionein expression in ductal breast tumors: correlation with estrogen receptor status.

Breast carcinoma is the most common malignancy in women. Estrogen is an important growth factor for breast tumor that plays an important role in regulating the proliferation and differentiation of normal and malignant mammary epithelial cells. Nuclear morphometry and metallothioneins (MTs) are indicators of proliferation that have been used as predictors of prognosis in many tumors. The present study aimed to study mean nuclear area (MNA) and MT; estrogen receptor (ER) expression in fibroadenoma (FA), ductal carcinoma in situ (DCIS), and infiltrating ductal carcinoma (IDC) of the breast. Also MNA and MT expression will be correlated with histologic grade and ER status in breast carcinoma. Breast tissues from 18 patients with FA, 10 patients with DCIS, and 40 patients with IDC were used in this study. MNA and MT expression; as proliferation markers; were investigated and correlated with ER status. All cases of FA, 7 out of 10 cases (70%) of DCIS and 23 out of 40 cases (57.5%) of IDC were positive for ER. MNA of cancer cells was significantly larger than that of normal and benign breast tissue. A significant direct correlation was found between MNA and histologic grades. MNA of ER-negative carcinomas was significantly larger than that of ER-positive tumors. In normal and benign breast tissue, myoepithelial cells consistently expressed the MT protein. Four out of 10 DCIS cases (40%) and 24 out of 40 cases of IDC cases (60%) were positively stained for MT. MT positivity was directly correlated with histologic grade of IDC. There was a highly significant inverse correlation between MT and ER overexpression. From this study, it is concluded that in invasive ductal carcinoma of the breast, the large MNA and MT overexpression are correlated with histologic grades and ER negativity. Therefore, large MNA and MT overexpression may be possible important indicators for more aggressive and less differentiated breast carcinoma.

Eccrine syringofibroadenoma with co-existent squamous cell carcinoma.

Eccrine syringofibroadenoma (ESFA) is a rare, benign adnexal tumor arising most often on the extremities of elderly individuals. It is typically a slow-growing, flesh- to reddish-colored nodule or plaque. Histologically, the tumor consists of anastomosing cords of cuboidal epithelial cells surrounded by a fibrovascular stroma containing plasma cells. The cords contain scattered ductal structures lined with cuboidal cells resembling eccrine ducts. The co-existence of ESFA with squamous cell carcinoma has been described, eliciting the term eccrine syringofibroadenoma. The differential diagnosis includes poroma, porocarcinoma, fibroepithelioma of Pinkus and clear cell acanthoma. ESFA stain positively with epithelial membrane antigen and carcinoembryonic antigen. Cytokeratin studies have been inconsistent.

[Immunohistochemical features of breast fibroadenomas].

9 breast fibroadenomas from females of different age who had a familial history of breast cancer were immunohistochemically studied. Having the same histological structure, the tumors differed in the expression of steroid hormone receptors, in the values of proliferation marker Ki-67 and oncomarker p53. It is concluded that the study of fibroadenoma may reveal breast carcinoma risk groups.