Case Of Low-grade Adenosquamous Carcinoma Research Articles

Abstract P1-05-31: A single center retrospective analysis of 259 cases of metaplastic breast cancer

Abstract Introduction: Metaplastic breast cancer (MBC) is a rare breast tumor.WHO histological classification of breast tumors in 2019 divided MBC into the following seven types: low-grade adenosquamous carcinoma, fibromatoid metaplastic carcinoma, squamous cell carcinoma, spindle cell carcinoma, metaplastic carcinoma with mesenchymal differentiation, mixed metaplastic carcinoma and myoepithelial carcinoma. Based on single center data, this study intends to conduct a detailed analysis of the clinicopathological features, treatment and prognostic factors of MBC. Methods:We collected 259 MBCs treated in our center from 2006 to 2022. The patient’s age, histological type, image feature, tumor size, lymph node metastasis, tumor stage, immunohistochemical information, surgical plan and systemic adjuvant therapy were summarized and considered to explore the factors affecting the overall survival rate (OS) and disease-free survival rate (DFS). T-test and chi-square test were performed on the data. P< 0.05 showed that the difference was statistically significant. Kaplan-Meier survival was used to analyze the long-term efficacy. Results: The incidence rate of MBC in breast cancer patients in our center is about 0.5%. They included 105 cases of squamous cell carcinoma (40.5%), 49 cases of mixed metaplastic carcinoma (18.9%), 41 cases of spindle cell carcinoma (15.8%), 27 cases of metaplasia carcinoma secreting matrix (10.4%), 6 cases of metaplastic carcinoma with mesenchymal differentiation (2.3%), 6 cases of myoepithelial carcinoma (2.3%), 3 cases of low-grade adenosquamous carcinoma (1.2%), 1 case of fibromatoid metaplasia carcinoma (0.4%) and 21 cases of unknown (8.1%). MBC were mainly three negative subtypes, which were 204 cases (78.8%), 41 cases (15.8%) luminal subtypes and 14 cases (5.4%) HER2 positive subtypes. There was no significant difference in the distribution of breast cancer subtypes among different histological types of MBC. There were 63 cases (24.3%) in clinical stage I, 171 cases (66.0%) in stage II, 23 cases (8.9%) in stage III and 2 cases (0.8%) in stage IV. 58 patients underwent core needle biopsy, of which only 7 (12.1%) reported histological types consistent with MBC. Among 154 patients with molybdenum target reports, 59 of them (38.3%) had malignant calcifications. The diagnostic coincidence rates of MRI, ultrasound and molybdenum target were 90.0%, 85.1% and 74.7% respectively. 258 cases of MBC received surgical treatment, including 183 cases of total mastectomy (70.9%), 53 cases of breast conserving surgery (20.5%) and 22 cases of quadrant resection (8.5%); 132 patients (51.2%) underwent axillary lymph node dissection and 93 patients (36.0%) underwent sentinel lymph node biopsy. 24 patients (9.3%) received neoadjuvant chemotherapy, of which only 2 (8.3%) achieved pathological complete remission. 56 patients (21.6%) received adjuvant radiotherapy, with a median of 25 times. 167 patients (64.5%) received adjuvant chemotherapy, and anthracycline sequential paclitaxel was the most commonly used regimen. The median follow-up was 31 months. The five-year DFS was 82.0%, and the five-year OS was 89.4%. Through Cox regression analysis, it was found that patients’ N stage (P=0.036) and receiving anthracycline sequential paclitaxel adjuvant chemotherapy (P=0.004) were independent prognostic factors. Conclusion: The histological types of MBC are complex. MRI is of high value in diagnosis. Conventional CNB is difficult to meet the needs of pathological tissue classification. Patients without lymph node metastasis and receiving anthracycline sequential paclitaxel adjuvant chemotherapy are associated with better prognosis. Through multidisciplinary standardized diagnosis and treatment, there is no significant difference between the prognosis of MBC and the common types of breast cancer. Keyword: metaplastic breast cancer; pathological characteristics; imaging; treatment; prognosis. Citation Format: Douwaner Liu, Jiajian Chen, Shuang Hao, Bingqiu Xiu, Qi Zhang, Liyi Zhang, Guangyu Liu, Zhimin Shao, Jiong Wu. A single center retrospective analysis of 259 cases of metaplastic breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-05-31.

A Case of Low-grade Adenosquamous Carcinoma of the Breast

A Case of Low-grade Adenosquamous Carcinoma of the Breast

A Case of Low-grade Adenosquamous Carcinoma of the Breast

乳腺の低異型度腺扁平上皮癌は化生癌に分類されるが，予後は良好な疾患である．今回，右乳癌に対し温存術を行い，8年後に同側乳房に低異型度腺扁平上皮癌を発症した1例を経験したので報告する．

Low-grade adenosquamous carcinoma of the breast: A diagnostic and clinical challenge

Adenosquamous carcinoma of the breast (ASBC) is a rare variant of metaplastic breast cancer with both glandular as well as squamous differentiation. Their lack of distinct imaging characteristics, sometimes subtle histological characteristics and overlapping features with other benign lesions pose a diagnostic challenge. Unlike other forms of metaplastic breast cancer, low-grade adenosquamous carcinoma (LGAC) tends to follow an indolent course with favourable prognosis. We reviewed eight cases of LGAC in our institution from June 2005 to March 2014. In six cases, LGAC was only found after excisional biopsy. In our patients, LGAC frequently co-existed with other forms of breast pathology. Two patients had incidental findings of LGAC alongside their primary malignant tumour (adenoid cystic carcinoma and invasive ductal carcinoma in one, four foci between 0.5 and 4.0 mm within a radial sclerosing lesion adjacent to a malignant phyllodes tumour in the other). A further four patients had LGAC within a complex sclerosing lesion. One patient had a focus of LGAC within a fibroadenoma. One had a focus of LGAC within a benign phyllodes tumour. None of the patients had evidence of nodal involvement. A high degree of suspicion is recommended as such lesions tend to be incidental histological findings within benign tumours or within complex sclerosing lesions. Although the risk of nodal and distant metastasis is low, the potential for local recurrence necessitates aggressive local excision with margin clearance. The role of axillary dissection has yet to be defined and routine sentinel node biopsy and axillary clearance may not be necessary in view of rarity of nodal metastasis in literature. Benefit from adjuvant radiotherapy or chemotherapy is not clearly defined. All eight patients in our study have shown no evidence of recurrence after definitive surgery but longer periods of surveillance is required.

Two cases of Low-Grade adenosquamous carcinoma of breast arising within complex sclerosing lesions in females under 20 years of age

Background and Aims Low-grade adenosquamous carcinoma (LGASC) of breast is a rare subtype of metaplastic carcinoma. An association with complex sclerosing lesions (CSL) has been described in older patients. 1,2 LGASC has not been previously reported in the literature in patients under the age of 20. We describe two cases of LGASC arising within large CSL in 18-year-old and a 19-year-old females. This study discusses the diagnostic difficulties and differential diagnoses of this entity, as well as the relationship between LGASC and CSL. Methods The two cases were received as part of the routine surgical workload at our laboratory. The slides were reviewed by multiple pathologists at our institution and both cases were referred to Prof. Ian Ellis for expert opinion. Results Immunohistochemistry features were consistent with LGASC. 3 The diagnoses were confirmed by Prof. Ellis. Discussion Although LGASC is classified as a variant of metaplastic carcinoma, it has a better prognosis with the principal risk being local recurrence. Thus distinction from benign entities, adequate excision and appropriate management is important, especially in young patients where treatment complications and cosmetic result are significant considerations. The pathogenesis of LGASC remains uncertain, however these cases add further evidence to the association between LGASC and CSL.

Low-grade adenosquamous carcinoma of the breast with diverse expression patterns of myoepithelial cell markers on immunohistochemistry: a case study.

This paper reports a case of low-grade adenosquamous carcinoma (LGASC) arising in a 69-year-old woman, who presented with a 1-cm palpable mass on her right breast. Core needle biopsy diagnosed the mass as a fibroadenoma. After six months, the mass increased in size, and the patient received subsequent mammotome excision. On microscopic examination, bland-looking small glands were infiltrating into the fibrotic stroma with lymphocytic infiltrates at the periphery. Hematoxylin and eosin staining revealed relatively easily detectable myoepithelial cells along the outside in each of the glandular structures with variable degrees of squamous metaplasia. Based on histologic features, the patient was diagnosed with LGASC. LGASC is a rare variant of metaplastic carcinoma, which is characterized by a favorable prognosis. Due to the bland cytology and presence of myoepithelial cells, LGASC can be misdiagnosed as benign lesion. Additionally, inconsistent expression of myoepithelial markers could aid the diagnosis of LGASC.

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.

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 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.

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.