Low-grade Adenosquamous Carcinoma Research Articles

Low-grade adenosquamous carcinoma of the breast

Low-grade adenosquamous carcinoma is a rare and unique form of invasive mammary carcinoma. Though it is categorised as a variant of metaplastic carcinoma, it differs from its counterparts in this...

Immunohistochemical Staining Characteristics of Low-grade Adenosquamous Carcinoma of the Breast

Low-grade adenosquamous carcinoma (LGASC) is an uncommon variant of metaplastic carcinomas of the breast. The immunohistochemical profile of this entity has not been well characterized and is likely because of its seemingly inconsistent staining patterns when commonly used immunohistochemical stains are employed. We set out to further elucidate the immunohistochemical profile of this uncommon entity in a sizable cohort of patients. Thirty cases of LGASC were identified in our files. Commonly used immunohistochemical stains such as myoepithelial and cytokeratin markers used to evaluate a small glandular proliferation in the breast (the differential diagnosis of which includes LGASC) were utilized. The pattern and location of immunoreactivity were recorded in each case. Results were compared for staining trends. All cases of LGASC demonstrated variable staining in both lesional glands and stromal cells for myoepithelial (p63, smooth muscle myosin, smooth muscle actin, CD10, calponin) and cytokeratin (CK AE1/3, CK5/6, CK7, CK 34βE12, Cam 5.2) markers. Within a single case, circumferential staining using myoepithelial markers was complete, discontinuous, and absent in over a third of the studied cases. A minority of cases showed either complete circumferential staining (or complete absence) by any single immunohistochemical stain. Lamellar staining of stromal cells surrounding glands was best highlighted using smooth muscle myosin heavy chain or calponin. Using cytokeratin stains, core staining (luminal glandular cells demonstrating distinctly stronger staining intensity than the basally located cells in the same gland) was observed in approximately half of the studied cases. These lesional stromal cells were negative for all cytokeratins, with the exception of 1, which was focally positive for 1 cytokeratin immunostain (CK7) while being negative for 3 others. LGASC consistently stains in an inconsistent manner using commonly used immunohistochemical stains. In addition, we found lamellar staining and core staining using myoepithelial and cytokeratin stains, respectively, to be distinctive and therefore diagnostically valuable.

Pathologic diagnosis and differential diagnosis of low-grade adenosquamous carcinoma of breast and syringomatous adenoma of nipple

To investigate the pathologic and immunohistochemical features, diagnosis and differential diagnosis of low-grade adenosquamous carcinoma of the breast and syringomatous adenoma of the nipple. Six cases of low-grade adenosquamous carcinoma of the breast and four cases of syringomatous adenoma of the nipple were examined histologically and immunohistochemically (MaxVision method), and the literature was reviewed. The two types of tumors were similar in morphology, but located in different regions with low-grade adenosquamous carcinoma being present in the deep parenchyma and syringomatous adenoma in nipple. Both types of tumors were composed mainly of well-differentiated glands with angulated, comma shaped or polliwog appearance in a disordered infiltrative pattern. The tumor cells also formed solid tubules, strips or nests, with frequent areas of squamoid differentiation. Mitosis was rare. The interstitial tissue showed abundant spindle cells or sclerotic fibrosis with mixed inflammatory cells infiltration. One case of low-grade adenosquamous carcinoma showed a concomitant malignant adenomyoepithelioma, and another case showed concomitant spindle cell metaplastic carcinoma. One case of syringomatous adenoma involved the deep parenchyma. Immunohistochemistry of low-grade adenosquamous carcinoma showed that CK5/6 and p63 were positive in the outer layer of the glands and the squamoid epithelium, and CD10 was also positive in the outer layer of the glands. ER and HER2 were negative, and PR was also negative except for one case in which the spindle cells were positive for CK5/6, AE1/AE3 and PR focally. Immunostaining of syringomatous adenoma demonstrated that p63 and CK5/6 were positive in the outer layer of the glands and the squamoid epithelium. Calponin, SMA, ER, PR and HER2 were all negative. Low-grade adenosquamous carcinoma of the breast and syringomatous adenoma of the nipple are similar in morphology and immunohistochemical phenotype, while the biological features are opposite due to different locations. The differential diagnoses include tubular carcinoma, adenosquamous carcinoma, radial sclerosing lesions and others.

Low-grade adenosquamous carcinoma of the breast—A case report with a BRCA1 germline mutation

Breast cancers occurring in women with germline BRCA1 mutations tend to fall into the category of triple-negative or basal-like phenotypes, such as metaplastic carcinoma. Low-grade adenosquamous carcinoma of the breast is a rare variant of metaplastic carcinoma. We present the case of a 49-year-old woman with a past medical history of invasive ductal breast carcinoma 13 years ago, and who was recently diagnosed as having a low-grade adenosquamous carcinoma in the same breast. Genetic analysis of blood DNA revealed a BRCA1 mutation. To our knowledge, BRCA1 mutation in association with a low-grade adenosquamous carcinoma of the breast has not yet been reported. Thus, it may be important to consider the possibility of an association, but supplemental studies are needed.

Nipple adenoma: report of 18 cases with review of literatures

To investigate the clinicopathological and immunohistochemical features, diagnosis and differential diagnosis of nipple adenoma of the breast. Morphological observation and immunohistochemistry were applied to 18 cases of nipple adenoma with a review of the related literatures. The neoplasms were localized at nipples or under the areola of breast, adherent to the epidermis, mainly composed of dilated ducts in a tubular appearance associated with fibrotic matrix. The glandular epithelium showed various type of proliferation, forming thick layers or complex structures such as papillae, micropapillae, tufts, fronds, arcades or bridges accompanying with solid or cribriform cell nests. The tumor cells were crowding, lack of an uniform morphology and polarity with intact myoepithelial cells around the ducts. By immunostaining, the glandular epithelium was diffusely positive for 34betaE12, patchily positive for CK5/6, and negative for p53 and c-erbB-2. The myoepithelium, positive for p63, smooth muscle actin and Calponin, was well preserved and outlining the ducts. Nipple adenoma is an infrequent type of benign breast neoplasm, presenting as sclerosing papilloma, papillomatosis or florid sclerosing adenosis. It is easily confused with atypical ductal hyperplasia/low grade ductal carcinoma in situ, invasive ductal carcinoma or low grade adenosquamous carcinoma. A correct diagnosis is based on the peculiar location and morphology of the tumor, and immunohistochemistry is helpful in some cases.

Infiltrating Syringomatous Adenoma of the Nipple: Clinical Presentation and Literature Review

Infiltrating syringomatous adenoma of the nipple is a rare neoplasm of the breast. Syringomatous adenoma of the nipple is often misdiagnosed because clinical examination and mammographic findings of syringomatous adenoma of the nipple mimic carcinoma. Despite its benign behavior, syringomatous adenoma of the nipple usually shows infiltrative expansile proliferation into adjacent tissue and underlying breast tissue. Up until now, to our knowledge, there has been no reported case of regional or distant metastasis. Histologically and clinically, syringomatous adenoma of the nipple is often confused with tubular carcinoma as well as low-grade adenosquamous carcinoma of the breast. Special attention given to this tumor by pathologists and clinicians can avoid misdiagnosis and unnecessary treatment.

Metaplastic Squamous Carcinoma of the Breast: Clinicopathologic Analysis of 17 Cases

Squamous cell carcinoma of the breast is very rare and it is considered to arisefrom metaplastic change of ductal carcinoma. Metaplastic squamous cell carcinoma (MSC) ofthe breast includes pure squamous cell carcinoma, metaplastic adenosquamous carcinomaand low grade adenosquamous carcinoma. Most of the cases of MSC of the breast were report-ed to have lymph node metastasis and this has a worse prognosis than that of conventionalinvasive ductal carcinoma.

Syringomatous Adenoma of the Nipple-Treatment by Central Mound Resection and Oncoplastic Reconstruction

Syringomatous adenoma (SA) of the nipple is a rare tumor first described by Rosen in 1983. It is histologically similar to skin adnexal tumors in other parts of the body. It has been reported under several names including low-grade adenosquamous carcinoma, SA of the nipple, and infiltrating SA of the nipple. Clinical examination and mammographic evidence yield high suspicion for carcinoma and often these lesions are misdiagnosed. Because the lesion involves the nipple, surgical treatment has ranged from local excision to mastectomy. There are 31 cases reported in the English literature, and although they all recommend complete excision, none describe reconstructive efforts. This case report describes a case of SA of the nipple presenting as a chronic abscess. We discuss the surgical treatment including reconstruction after central mound resection as well as pathological findings.

Preoperative and intraoperative diagnosis of low‐grade adenosquamous carcinoma of the breast: potential diagnostic pitfalls

Low-grade adenosquamous carcinoma (LGAC), a rare variant of metaplastic breast cancer, may mimic benign or other low-grade malignant lesions histologically. Diagnostic difficulty may be encountered when evaluating breast cytology, core needle biopsy or intraoperative frozen section specimens. Pathology reports, cytology aspirates and histological slides of LGAC diagnosed at the Department of Pathology, Singapore General Hospital, were reviewed. Four cases of LGAC were analysed. Cytology from the first case showed atypical cells and the subsequent surgical excision specimen showed a complex sclerosing lesion with LGAC. The second and third cases were investigated by core needle biopsies: the preoperative histological features were suggestive of but not diagnostic of LGAC, until further excision biopsies were performed. The fourth case entailed a frozen section specimen, for which definitive diagnosis was deferred to paraffins. The patients remained well with no evidence of recurrent disease to date. When limited material, in the form of needle aspirates, core biopsy specimens or frozen sections, is submitted for histology, making a diagnosis of LGAC is not only challenging, but may be impossible. In difficult cases, careful pathological assessment, clinicopathological correlation and follow-up or complete excision biopsy may prove invaluable in establishing a definitive diagnosis.

Fine-needle aspiration cytology and immunohistology of low-grade adenosquamous carcinoma of the breast

Fine-needle aspiration cytology and immunohistology of low-grade adenosquamous carcinoma of the breast

Carcinomas of the breast showing myoepithelial cell differentiation. A review of the literature.

Myoepithelial cells are normally located between the epithelial cells and the basal lamina of secretory elements of exocrine glands. Their role in the histogenesis of breast tumours has been studied extensively, and a definite differentiation towards myoepithelial cells has been demonstrated in adenoid cystic carcinoma, adenomyoepithelioma, low-grade adenosquamous (syringomatous) carcinoma, pure malignant myoepithelioma and poorly differentiated myoepithelial-rich breast carcinoma. All these tumours are of low malignancy, with the exception of malignant myoepithelioma and poorly differentiated myoepithelial-rich carcinoma. When a low-grade tumour is associated with a spindle cell component, distant metastases must be expected. Pure malignant myoepithelioma shows morphological and clinical features similar to those of monophasic sarcomatoid carcinomas, and it is possible that this last tumour is linked histogenetically to sarcomatoid carcinomas.

Poorly differentiated myoepithelial cell rich carcinoma of the breast.

Three unusual cases of invasive breast carcinoma are reported, each comprising a dual malignant cellular proliferation consisting of 'ordinary' epithelial cells as well as myoepithelial cells haphazardly intermingled. The cases displayed features which did not match any of the four main types of invasive malignant breast tumours containing myoepithelial elements, i.e. adenomyoepithelioma, adenoid cystic carcinoma, pure myoepithelioma and low-grade adenosquamous carcinoma. The designation of 'poorly differentiated myoepithelial cell rich carcinoma' (PDMC) is proposed for these tumours.

Fine‐needle aspiration of low grade adenosquamous carcinoma of the breast

Low-grade adenosquamous carcinoma is an unusual variant of mammary carcinoma. This malignancy generally presents as a palpable mass without mammographic microcalcifications, and fine-needle aspiration may be the initial technique selected for diagnosis. To our knowledge, the cytologic findings associated with this neoplasm have not been reported. We report a case of low-grade adenosquamous carcinoma of the breast in a 57-yr-old woman, initially studied by fine-needle aspiration cytology and confirmed by excisional biopsy. The aspiration biopsy smears were characterized by low cellularity and small disoriented clusters containing uniform cells of small to medium size. Bipolar cells were not seen in the background. The diagnostic features and differential diagnosis of this unusual neoplasm are reviewed. Diagn Cytopathol 1996;14:321–324. © 1996 Wiley-Liss, Inc.

Adenomyoepithelioma of the breast associated with low-grade adenosquamous and sarcomatoid carcinomas

Six cases of invasive breast carcinoma with unusual morphological features are reported. The ages of the female patients ranged from 46 to 79 years (mean 60.5). All tumours had areas typical of an adenomyoepithelioma. In three cases adenomyoepithelioma gradually merged with low-grade adenosquamous carcinoma. In the other three patients a sarcomatoid carcinoma was associated with adenomyoepithelial areas. A common origin is proposed for these neoplasms, which extends the morphological spectrum of epi-myoepithelial cell tumours.

Low-Grade Adenosquamous Carcinoma of the Breast

Low-grade adenosquamous carcinoma of the breast is an uncommon neoplasm of uncertain pathogenesis, clinical behavior, and malignant potential. This report describes the clinical and pathologic features of 32 cases of low-grade adenosquamous carcinoma. All patients presented with palpable tumors ranging from 0.6 to 8.6 cm (mean, 2.8 cm). Origin from an intraductal papillary tumor was found in 12 cases, including three with adenomyoepitheliomatous features. Electron microscopy disclosed glandular and squamous differentiation; the squamous cells often lined ducts that were structurally analogous to the acrosyringium of the eccrine sweat gland. Treatment consisted of mastectomy (13 patients) or excisional biopsy (19 patients). A single lymph node in one patient with a 3.5-cm primary carcinoma harbored metastatic adenocarcinoma. Axillary dissection revealed no metastases in 11 other patients. Another patient with an 8.0-cm breast tumor had metastatic adenosquamous carcinoma in the lung at initial diagnosis. After follow-up of 12 to 124 months, 20 of 25 patients had no recurrence. Five women treated by excisional biopsy had local recurrences in the breast. In one patient, the local recurrence was ultimately fatal due to invasion of the hemithorax. Estrogen and progesterone receptor studies were negative in 13 of 15 cases studied by biochemical analysis. The two tumors that were hormone-receptor positive were histologically associated with a papilloma and an adenomyoepithelioma, respectively. In the latter case, immunohistochemical studies showed the carcinoma to be hormone-receptor negative. Hormone receptor activity was limited to the adenomyoepitheliomatous component. This study confirms the largely indolent, but locally aggressive, clinical course of low-grade adenosquamous carcinoma of the breast. Although complete limited excision of small lesions may be curative, tumors greater than 3.0 cm may require more aggressive therapy.