RESUMEN

Microglandular adenosis (MGA) and atypical microglandular adenosis (AMGA) are intensely rare and distinctive forms of adenosis of the breast, usually occurring in middle-aged women. Carcinoma arising in MGA is an extremely rare subtype of breast carcinoma, and most reported cases are of invasive carcinoma. Ultrasound and magnetic resonance imaging are accurate imaging modalities for diagnosing these abnormalities. Our goal in this article was to report a rare instance of ductal carcinoma in situ (DCIS) arising from MGA and AMGA in a very young Vietnamese woman who presented with a palpable mass in her right breast for 1 month. During clinical examination and imaging, suspected lesions were found and categorized as BI-RADS 4a. The final histopathological findings confirmed DCIS arising from MGA/AMGA. In this patient, the disease was detected and managed early when the lesion was localized in the duct and there were no signs of invasive ductal carcinoma.

RESUMEN

Breast cancer is the most common cancer among women and the leading cause of cancer-related deaths globally. Ductal carcinoma of no special type is the most prevalent, followed by lobular carcinoma. Finding a triple-negative breast cancer of intermediate grade on core biopsies should raise the possibility of dealing with one of the rare subtypes such as microglandular adenosis (MGA)-associated carcinoma. Here, we present a case of a 40-year-old female, who presented with bilateral breast masses, in which one of them was a high-grade carcinoma and the other turned out to be an MGA-associated carcinoma, which was misdiagnosed initially on the core biopsy as a grade II triple-negative ductal carcinoma of no special type. Such diagnosis is challenging to pathologists, especially on small biopsies where the full morphological spectrum is not evident.

RESUMEN

Microglandular adenosis (MGA) is a proliferative breast lesion composed of small, uniform glands lacking a myoepithelial cell layer while still invested by the basement membrane. The glands percolate haphazardly through the breast parenchyma rather than maintaining a lobular architecture, typical of other forms of adenosis.MGA is a benign lesion though atypical forms have been well described, often in close association with carcinoma. MGA, atypical MGA (AMGA), and the vast majority of MGA-associated carcinomas (MGACA) are negative for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor 2 (HER2) by immunohistochemistry. In light of these findings and early molecular studies, MGA is hypothesized to represent a clonal process and nonobligate precursor of basal-type breast carcinomas. We present the case of a 58-year-old woman and the first published molecular comparison of a luminal-type invasive ductal carcinoma with its associated MGA/AMGA. Analysis of small nucleotide variants (SNVs) revealed that 63% of the SNVs identified in the MGA were present in the AMGA while only 10% of them were present in the MGACA, suggesting a direct relationship between MGA and AMGA but not MGA and MGACA.

RESUMEN

The presented case describes the difficulties of diagnosis of the breast microglandular adenosis (MGA), taken by clinicians for a malignant process due to the nature of growth and large size. Criteria for histological and immunohistochemical diagnosis and differentiation of MGA with malignant neoplasms, in particular, with tubular breast carcinoma, are presented. Taking into account the rarity of the pathology and the absence of described cases in the Russian-language literature, the observation is of interest to pathologists and clinicians.

Asunto(s)

Neoplasias de la Mama , Carcinoma Ductal de Mama , Enfermedad Fibroquística de la Mama , Femenino , Humanos , Enfermedad Fibroquística de la Mama/diagnóstico , Enfermedad Fibroquística de la Mama/patología , Inmunohistoquímica , Carcinoma Ductal de Mama/diagnóstico , Carcinoma Ductal de Mama/patología , Diagnóstico Diferencial , Neoplasias de la Mama/diagnóstico

RESUMEN

Acinic cell carcinoma (ACC) is an exceptionally rare type of breast carcinoma with a low-grade morphology and a favorable prognosis. It is postulated to be a type of invasive carcinoma arising in microglandular adenosis (MGA). We report a case of extensively spreading ACC of the breast with MGA-like features. Macroscopically, yellowish nodules were widely distributed throughout the right breast, up to the axilla, without mass formation. Microscopically, the tumor consisted of two distinct carcinoma components: one was multiple nodular lesions showing invasive carcinoma with fused solid nests, and the other was a widely spreading lesion exhibiting MGA-like features with uniform small single glands. Immunohistochemically, both components were negative for ER, PR, and HER2, and expressed EMA, S100 and lysozyme. The distinct morphology and molecular expression indicated ACC. The single glands in the MGA-like area lacked myoepithelial cells but were linearly surrounded by type IV collagen, a basement membrane component. This case supports the hypothesis that ACC and MGA have the same lineage and indicates that ACC is not necessarily a low-grade malignancy and can be aggressive.

Asunto(s)

Neoplasias de la Mama , Carcinoma de Células Acinares , Carcinoma , Enfermedad Fibroquística de la Mama , Femenino , Humanos , Carcinoma de Células Acinares/patología , Mama/patología , Neoplasias de la Mama/patología , Enfermedad Fibroquística de la Mama/química , Enfermedad Fibroquística de la Mama/metabolismo , Enfermedad Fibroquística de la Mama/patología , Carcinoma/patología

RESUMEN

Microglandular adenosis is a non-lobulocentric haphazard proliferation of small round glands composed of a single layer of flat to cuboidal epithelial cells. The glandular structures lack a myoepithelial layer; however, they are surrounded by a basement membrane. Its clinical course is benign, when it is not associated with invasive carcinoma. In around 30% of cases, there is a gradual transition to atypical microglandular adenosis, carcinoma in situ, and invasive breast carcinoma of several different histologic subtypes, including an invasive carcinoma of no special type, metaplastic matrix-producing carcinoma, secretory carcinoma, metaplastic carcinoma with squamous differentiation, acinic cell carcinoma, spindle cell carcinoma, and adenoid cystic carcinoma. Recent molecular studies suggest that microglandular adenosis is a non-obligate precursor of triple-negative breast carcinomas. In this manuscript, we present a unique case of microglandular adenosis associated with metaplastic matrix-producing carcinoma and HER-2 neu oncoprotein positive pleomorphic lobular carcinoma in situ with apocrine differentiation in a 79-year-old patient.

RESUMEN

Acinic cell carcinoma (AcCC) of breast is a rare subtype of triple-negative breast carcinoma demonstrating a wide morphologic spectrum. In this study, we perform a detailed morphologic and immunohistochemical description of two cases of the rare entity and review the published relative literature. Histologically, the two cases both showed predominantly microglandular and solid structures overlapping with the histological features of microglandular adenosis (MGA), and one case presented spindle cell metaplastic carcinoma with chondromyxoid matrix as a minor morphologic pattern. In two cases, most of the cancer cells were positive for lysozyme and antitrypsin strongly and extensively, but negative for estrogen receptor (ER), progesterone receptor (PR), androgen receptors (AR) and human epidermal growth factor receptor 2 (HER2). The true relationship between breast AcCC and MGA or carcinoma arising in MGA(CAMGA) may remain unclear; re-excision is advised when the MGA-like content extends to the surgical margins in the setting of breast AcCC. More cases and further molecular investigations are required to elucidate the true histogenesis and give the patients appropriate treatment.

Asunto(s)

Neoplasias de la Mama , Carcinoma de Células Acinares , Carcinoma , Enfermedad Fibroquística de la Mama , Neoplasias de la Mama Triple Negativas , Neoplasias de la Mama/patología , Carcinoma/patología , Carcinoma de Células Acinares/diagnóstico , Carcinoma de Células Acinares/patología , Femenino , Enfermedad Fibroquística de la Mama/metabolismo , Enfermedad Fibroquística de la Mama/patología , Enfermedad Fibroquística de la Mama/cirugía , Humanos , Inmunohistoquímica , Neoplasias de la Mama Triple Negativas/patología

RESUMEN

Classification of breast tumors has been evolving in the last decade. Uncommon types of breast neoplasms have been increasingly recognized. While the pathogenesis of a subset of these tumors remains to be ascertained, integration of state-of-the-art knowledge from molecular advancements and clinical practice has enhanced our understanding of these diseases, be they unique to the breast or more frequently seen in other organs. Furthermore, these lesions may have diverse clinical outcomes despite of similar histopathologic and immunophenotypic characteristics or even molecular alterations, thus warranting different clinical management. Therefore, recognizing their salient histologic features and judicious use of ancillary studies is essential to reach the correct diagnosis in the pursuit of personalized medicine. This review provides an update on selective special types of breast neoplasms, with emphasis on their salient clinicopathologic features, diagnostic pitfalls, controversies, and recent molecular genetic advances.

Asunto(s)

Neoplasias de la Mama , Enfermedad Fibroquística de la Mama , Mama/patología , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Diagnóstico Diferencial , Femenino , Enfermedad Fibroquística de la Mama/diagnóstico , Enfermedad Fibroquística de la Mama/patología , Humanos , Biología Molecular

RESUMEN

Acinic cell carcinoma of the breast is a rare subtype of triple-negative breast cancer that recapitulates the appearance of tumors seen in salivary glands. We present the case of a 42-year-old woman with an irregular, nontender mass above the left nipple during routine obstetric appointment at 24 weeks gestation. She was subsequently diagnosed with triple-negative invasive ductal carcinoma of the left breast, Nottingham grade 3, via core needle biopsy. She was treated with neoadjuvant therapy (doxorubucin and cyclophosphamide) antenatally and paclitaxel in the postpartum period followed by left mastectomy with sentinel node biopsy. The carcinoma in the mastectomy specimen showed a spectrum of morphologic patterns with immunohistochemistry revealing strong positivity for alpha-1-antichymotrypsin, epithelial membrane antigen (EMA), lysozyme, and S100. The histomorphology paired with the immunoprofile led us to the diagnosis of acinic cell carcinoma. We retrospectively performed immunostains in the core biopsy specimen, which demonstrated GATA-3 and DOG-1 positivity. Next-generation sequencing of the postneoadjuvant specimen using a 70-gene panel revealed 2 single-nucleotide variant (SNV) mutations: tumor protein 53 (TP53) (c.747G>T) SNV mutation and rearranged during transfection (RET) (c.2899G>A) SNV mutation.

Asunto(s)

Biomarcadores de Tumor/análisis , Mama/patología , Carcinoma de Células Acinares/diagnóstico , Complicaciones Neoplásicas del Embarazo/diagnóstico , Neoplasias de la Mama Triple Negativas/diagnóstico , Adulto , Anoctamina-1/análisis , Anoctamina-1/metabolismo , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Mama/cirugía , Carcinoma de Células Acinares/genética , Carcinoma de Células Acinares/patología , Análisis Mutacional de ADN , Femenino , Factor de Transcripción GATA3/análisis , Factor de Transcripción GATA3/metabolismo , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Inmunohistoquímica , Mastectomía , Proteínas de Neoplasias/análisis , Proteínas de Neoplasias/metabolismo , Polimorfismo de Nucleótido Simple , Embarazo , Complicaciones Neoplásicas del Embarazo/genética , Complicaciones Neoplásicas del Embarazo/patología , Proteínas Proto-Oncogénicas c-ret/genética , Biopsia del Ganglio Linfático Centinela , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/patología , Proteína p53 Supresora de Tumor/genética

RESUMEN

The risk of secondary tumors in patients who have received mediastinal radiation therapy is well-known. Microglandular adenosis of the breast is a rare lesion that is considered benign, although its possible role as a precursor of invasive breast carcinoma has been considered. We present a case of microglandular adenosis in a patient who received mediastinal radiation therapy in childhood for Hodgkin's lymphoma. To our knowledge, this is the first reported case of microglandular adenosis in a patient with mediastinal radiotherapy which may shed light on its pathogenesis.

Asunto(s)

Neoplasias de la Mama , Enfermedad Fibroquística de la Mama , Enfermedad de Hodgkin , Traumatismos por Radiación , Neoplasias de la Mama/etiología , Femenino , Enfermedad Fibroquística de la Mama/etiología , Enfermedad de Hodgkin/radioterapia , Humanos

RESUMEN

Microglandular adenosis (MGA) of the breast is exceedingly rare, with only a few case reports and series published to date. Previous studies have elegantly demonstrated the progression of benign MGA to atypical MGA to MGA-in situ carcinoma to invasive carcinoma and therefore suggest MGA as a possible non-obligate precursor lesion to a subset of breast carcinomas. Immunohistochemically, MGA is negative for estrogen receptor (ER), progesterone receptor (PR), and HER2-neu oncoprotein expression, and carcinomas arising in the setting of MGA are often reported to be triple negative. In this article, we present a unique case of an ER+/PR+/HER2- invasive carcinoma associated with MGA and atypical MGA. Our case highlights the diagnostic pitfall of MGA and suggests that MGA is a heterogeneous group of lesions with potential for either luminal-type or basal-type differentiation during progression to breast carcinoma.

Asunto(s)

Neoplasias de la Mama/patología , Mama/patología , Carcinoma Ductal de Mama/patología , Enfermedad Fibroquística de la Mama/patología , Lesiones Precancerosas/patología , Biomarcadores de Tumor/análisis , Biomarcadores de Tumor/metabolismo , Mama/diagnóstico por imagen , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/cirugía , Carcinoma Ductal de Mama/diagnóstico , Carcinoma Ductal de Mama/cirugía , Progresión de la Enfermedad , Femenino , Enfermedad Fibroquística de la Mama/diagnóstico , Enfermedad Fibroquística de la Mama/cirugía , Humanos , Mamografía , Mastectomía , Persona de Mediana Edad , Lesiones Precancerosas/diagnóstico , Lesiones Precancerosas/cirugía

RESUMEN

Microglandular adenosis (MGA) is a rare breast lesion reported to be associated with invasive carcinoma in up to 20% to 30% of cases and has been proposed as a nonobligate precursor to basal-like breast cancers. We identified a case of matrix-producing metaplastic carcinoma with morphologic and immunohistochemical evidence of progression from MGA to atypical MGA, carcinoma in situ, and invasive carcinoma. We performed whole-exome sequencing of each component (MGA, atypical MGA, carcinoma in situ, and cancer) to characterize the mutational landscape of these foci. There was a significant copy number overlap between all foci, including a segmental amplification of the CCND1 locus (partial chromosome 11 trisomy) and MYC (8q24.12-13). Using a bioinformatics approach, we were able to identify 3 putative mutational clusters and recurrent, stop-gain nonsynonymous mutations in both ZNF862 and TP53 that were shared across all foci. Finally, we identified a novel deleterious splice-acceptor site mutation of chr5:5186164 G>T (chromosome 5p15) encoding the gene, ADAMTS16, in the invasive component.

Asunto(s)

Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/patología , Enfermedad Fibroquística de la Mama/patología , Lesiones Precancerosas/patología , Proteínas ADAMTS/metabolismo , Neoplasias de la Mama/metabolismo , Carcinoma Ductal de Mama/metabolismo , Progresión de la Enfermedad , Femenino , Enfermedad Fibroquística de la Mama/metabolismo , Humanos , Inmunohistoquímica , Lesiones Precancerosas/metabolismo , Proteína p53 Supresora de Tumor/metabolismo

RESUMEN

Microglandular adenosis (MA) of the breast, a benign glandular proliferation, was originally described approximately 35 years ago. The lesion is constituted by small glands, all of the same size. Glands are lined by one layer of cuboidal epithelial cells encircled by basal lamina without any evidence of interposed myoepithelial elements. Cells are positive for low-weight keratins and S-100 protein and negative for estrogen receptor, progesterone receptor, and HER-2. Since then, in the years that followed, several malignant lesions all showing microglandular architecture have been regarded either as a precursor or as an equivalent manifestation of MA. The latter has been associated with a large number of malignancies that include ductal carcinoma in situ, lobular carcinoma in situ, ademyoepithelioma, high-grade basal-like carcinoma, adenoid cystic carcinoma, matrix-producing carcinoma, invasive duct carcinoma not otherwise specified, and spindle cell carcinoma, not to mention acinic cell carcinoma. None of the above tumors were identical to MA. Differences mainly rested not only on the specific structure of the small glands but also on the cytological composition and immunohistochemical features of different lesions. Here, a review of the features of MA together with the differential diagnosis with lesions showing microglandular structure is discussed. MA shows similarities to a lesion named microglandular hamartoma/adenosis of the nasal cavity. The relation of the 2 similar lesions is discussed.

Asunto(s)

Neoplasias de la Mama/patología , Proliferación Celular , Enfermedad Fibroquística de la Mama/patología , Glándulas Mamarias Humanas/patología , Lesiones Precancerosas/patología , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/análisis , Biopsia , Neoplasias de la Mama/química , Neoplasias de la Mama/cirugía , Diagnóstico Diferencial , Femenino , Enfermedad Fibroquística de la Mama/química , Enfermedad Fibroquística de la Mama/cirugía , Humanos , Inmunohistoquímica , Glándulas Mamarias Humanas/química , Glándulas Mamarias Humanas/cirugía , Persona de Mediana Edad , Lesiones Precancerosas/metabolismo , Lesiones Precancerosas/cirugía , Valor Predictivo de las Pruebas

RESUMEN

Mammary carcinoma arising in microglandular adenosis (MGA) is extremely rare, and MGA is regarded as a non-obligate precursor of triple-negative breast cancer. We report five cases of carcinoma arising in MGA of the breast. All cases showed a spectrum of proliferative lesions ranging from MGA to atypical MGA, ductal carcinoma in situ or invasive carcinoma. Immunohistochemically, all cases were triple-negative and expression of S-100 protein gradually decreased as the lesions progressed from MGA to atypical MGA and carcinoma. Three cases showed acinic cell differentiation with reactivity to α1-antitrypsin, and one case was metaplastic carcinoma. During clinical follow-up, one patient developed local recurrence. Carcinoma arising in MGA is a rare but distinct subset of triple-negative breast cancer with characteristic histologic and immunohistochemical findings.

RESUMEN

Mammary carcinoma arising in microglandular adenosis (MGA) is extremely rare, and MGA is regarded as a non-obligate precursor of triple-negative breast cancer. We report five cases of carcinoma arising in MGA of the breast. All cases showed a spectrum of proliferative lesions ranging from MGA to atypical MGA, ductal carcinoma in situ or invasive carcinoma. Immunohistochemically, all cases were triple-negative and expression of S-100 protein gradually decreased as the lesions progressed from MGA to atypical MGA and carcinoma. Three cases showed acinic cell differentiation with reactivity to α1-antitrypsin, and one case was metaplastic carcinoma. During clinical follow-up, one patient developed local recurrence. Carcinoma arising in MGA is a rare but distinct subset of triple-negative breast cancer with characteristic histologic and immunohistochemical findings.

Asunto(s)

Humanos , Células Acinares , Mama , Carcinoma Intraductal no Infiltrante , Enfermedad Fibroquística de la Mama , Estudios de Seguimiento , Recurrencia , Proteínas S100 , Neoplasias de la Mama Triple Negativas

RESUMEN

Microglandular adenosis (MGA) and atypical MGA (AMGA) are unusual lesions of the breast. They were once regarded as benign proliferative lesions and innocent bystanders. Several lines of evidence suggested that they could be neoplastic, clonal lesions and a non-obligate precursor for triple-negative breast cancers (TNBC). Recent work published in The Journal of Pathology by Guerini-Rocco and colleagues provided further evidence regarding the precursor-product relationship between MGA/AMGA and TNBC. Using a massively parallel sequencing approach, they demonstrated that MGA/AMGA, particularly those associated with TNBC, could be clonal neoplastic lesions showing clonal non-synonymous mutations, but none in pure MGA. Importantly, those alterations were observed in the associated TNBC. They were also able to identify recurrent alterations in TP53 in those MGA/AMGA cases as well as their associated TNBC. The findings, in conjunction with others, underscore the significance for MGA in clinical diagnosis. The potential of a benign lesion to progress into an aggressive malignant tumour implies that modification of the current management approach may be necessary. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Asunto(s)

Enfermedad Fibroquística de la Mama , Neoplasias de la Mama Triple Negativas , Mama , Neoplasias de la Mama , Carcinoma Ductal de Mama/genética , Femenino , Humanos , Reino Unido

RESUMEN

Matrix-producing carcinoma (MPC) of the breast is an extremely rare variant of metaplastic breast carcinoma that contains a mixture of epithelial and mesenchymal elements. As overt carcinoma with direct transition to a cartilaginous and/or osseous stromal matrix cells, MPC is of no spindle cells between those two elements. This is the case of a 43 year-old female patient with MPC which coexisted with microglandular adenosis (MGA), atypical MGA (AMGA) and carcinoma in situ arising in MGA (MGACA in situ). MGA is a rare, infiltrative, benign lesion of the breast with an indolent clinical course. Histological evidence of carcinoma arising from MGA has previously been documented. MPC arising in MGA is an extremely rare subtype of breast carcinoma and has been seldom detailed described in the previous studies. This report highlights one such case with cytomorphological and histopathological correlation, along with a review of pertinent literature and differential diagnosis.

Asunto(s)

Neoplasias de la Mama/química , Carcinoma in Situ/química , Matriz Extracelular/química , Enfermedad Fibroquística de la Mama/química , Adulto , Biomarcadores de Tumor/análisis , Biopsia , Neoplasias de la Mama/patología , Neoplasias de la Mama/cirugía , Carcinoma in Situ/patología , Carcinoma in Situ/cirugía , Matriz Extracelular/patología , Femenino , Enfermedad Fibroquística de la Mama/patología , Enfermedad Fibroquística de la Mama/cirugía , Humanos , Inmunohistoquímica , Escisión del Ganglio Linfático , Mamografía , Mastectomía Radical Modificada , Ultrasonografía Doppler en Color , Ultrasonografía Mamaria/métodos

RESUMEN

Carcinoma arising in microglandular adenosis (MGACA) is an extremely rare subtype of breast carcinoma. In this study, clinicopathological analysis of MGACA from 11 Chinese patients was conducted. Microscopically, all cases showed a spectrum of structure and glandular proliferations ranging from microglandular adenosis (MGA) to atypical MGA (AMGA) to MGACA. Carcinoma components were composed of high grade ductal carcinoma in situ (DCIS) in 1 case and invasive carcinoma in 10 cases. Invasive carcinomas were grade 3 in 10 tumors and grade 2 in 1. Invasive components in 5 of 10 cases were composed of invasive carcinoma of no special type (NST), and 1 case showed partially acinic cell differentiation. In 5 cases, invasive components were mixed of NST and matrix-producing carcinoma (MPC). All epitheliums in 11 cases were triple negative (ER-, PR-, HER2-), and diffuse positive for CK and S-100 protein. No myoepithelial cells were demonstrable from MGA to invasive components with immunohistochemical staining for P63 and calponin. PAS or reticulin stain showed the presence of a basement membrane around glands in MGA, AMGA, DCIS, and its absence in invasive components. Follow-up time ranged from 10 to 64 months. One patient developed a lung metastasis 24 months after surgery, 10 patients have been alive without recurrence. Our study revealed that MGACA is a distinct subset of breast carcinoma, with triple negative phenotype, high grade nuclear and variable morphology. Despite histopathologic and immunohistochemical features usually associated with a poor prognosis, MGACA seems to have a relatively favorable outcome.

Asunto(s)

Carcinoma/patología , Enfermedad Fibroquística de la Mama/patología , Neoplasias de la Mama Triple Negativas/patología , Adulto , Biomarcadores de Tumor/análisis , Biopsia , Carcinoma/química , Carcinoma/cirugía , Diferenciación Celular , Proliferación Celular , China , Femenino , Enfermedad Fibroquística de la Mama/química , Enfermedad Fibroquística de la Mama/cirugía , Humanos , Inmunohistoquímica , Neoplasias Pulmonares/secundario , Persona de Mediana Edad , Clasificación del Tumor , Invasividad Neoplásica , Fenotipo , Factores de Tiempo , Resultado del Tratamiento , Neoplasias de la Mama Triple Negativas/química , Neoplasias de la Mama Triple Negativas/secundario , Neoplasias de la Mama Triple Negativas/cirugía

RESUMEN

Microglandular adenosis (MGA) of the breast is a very rare and benign proliferative lesion. Most patients complain of a palpable breast mass that may arouse a clinical suspicion of breast cancer. Histopathologically, it is hard to distinguish MGA from breast cancer because of the lack of a myoepithelial layer and infiltrative proliferation. Several studies have reported a strong relationship between MGA and carcinoma arising in MGA, so the mass should be excised completely in cases of MGA determined from a core needle biopsy rather than observation. A 72-years-old woman presented with a palpable breast mass. On physical examination, a mass was palpable in the right upper outer quadrant area and somewhat fixed to the surrounding tissues and pectoralis major muscle. We could not detect any mass or dense lesion on mammography because of a grade 4 dense breast. Ultrasonographic findings revealed a low echoic lesion with indistinct margins. The result of a core needle biopsy was MGA, which was confirmed by excision. We report one case of MGA, which was believed to breast cancer clinically.

RESUMEN

Microglandular adenosis (MGA) of the breast is a very rare and benign proliferative lesion. Most patients complain of a palpable breast mass that may arouse a clinical suspicion of breast cancer. Histopathologically, it is hard to distinguish MGA from breast cancer because of the lack of a myoepithelial layer and infiltrative proliferation. Several studies have reported a strong relationship between MGA and carcinoma arising in MGA, so the mass should be excised completely in cases of MGA determined from a core needle biopsy rather than observation. A 72-years-old woman presented with a palpable breast mass. On physical examination, a mass was palpable in the right upper outer quadrant area and somewhat fixed to the surrounding tissues and pectoralis major muscle. We could not detect any mass or dense lesion on mammography because of a grade 4 dense breast. Ultrasonographic findings revealed a low echoic lesion with indistinct margins. The result of a core needle biopsy was MGA, which was confirmed by excision. We report one case of MGA, which was believed to breast cancer clinically.

Asunto(s)

Femenino , Humanos , Biopsia con Aguja Gruesa , Mama , Neoplasias de la Mama , Enfermedad Fibroquística de la Mama , Mamografía , Músculos , Examen Físico