Expression of hormone receptors in low-grade adenosquamous carcinoma of the breast

Abstract

Rationale:Low-grade adenosquamous carcinoma (LGASC) is a rare subtype of metaplastic breast carcinoma which is generally recognized as a characteristic subgroup of triple-negative breast cancers previously. However, in this study, we reported for the first time a case of LGASC with hormone receptors expression.Patient concerns:Pathological analysis of breast tumor specimen obtained by a 42-year-old female patient was performed. Morphologically, it composed of glandular structures with scattered squamous differentiation accompanied by haphazard arrangement of spindle cell stroma. Immunohistochemically, all myoepithelial and squamous differentiation markers showed typical LGASC positive or negative staining pattern. Interestingly, we found that normally aberrant hormone receptors were reactivated in this case. To our knowledge, this is the first report of a hormone receptor-positive LGASC. Apart from this, in the extended resection sample, we found scattered squamous metaplasia and florid adenosquamous proliferation (ASP). Meanwhile, it was positive for CD44 variant isoforms (CD44v), which is a breast cancer stem cell (CSC) marker, and expressed in LGASC, squamous metaplasia, and ASP.Diagnosis:LGASC with hormone receptors expression.Interventions:The breast-extended local excision and axillary lymph node dissection were performed.Outcomes:The patient was free of local recurrence and distant metastasis 6 months after surgical resection.Lessons:We herein report the first case of LGASC with immunoreactivity for hormone receptors, expanding its profile of immunophenotypes. CD44v may play an important role in the transition of LGASC precursor lesions into malignant processes, which may serve as a therapeutic target in LGASC.

Adenosquamous carcinoma of the breast: a population-based study

“…Five-year survival rate of ASC subgroup with hormone receptor positive was far less than that of the HR-negative subgroup, this result was contrary to IDC patients. There was a case report suggesting that when the expression of hormone receptors was positive in ASC, CD44v could play an important role in the transition of LGASC precursor lesions into malignant processes [ 7 ]. CD44v, a widely accepted cancer stem cell (CSC) marker in breast cancer, was considered to promote the tumor progression in various cancers [ 19 ].…”

“…Though several case reports and case series were published over the years [ 4 , 5 ], ASC remains poorly defined by immunohistochemistry and its genetic profile is still unclear [ 6 ]. From these limited studies, it appears that ASC differs from its counterparts in this heterogeneous category by its relative clinical indolence, also reflects histologically in its cytomorphology [ 7 ]. Under normal conditions, squamous carcinoma (SCC) of the breast must be considered in the differential diagnosis as many reports have included tumors with varying proportions of squamous carcinoma and adenocarcinoma, very few are completely pure without other kind of glandular cell differentiation [ 8 ].…”

Adenosquamous Carcinoma of the Breast: A Population-Based Study Using the SEER Database

“…Five-year survival rate of ASC subgroup with hormone receptor positive was far less than that of the HR-negative subgroup, this result was contrary to IDC patients. There was a case report suggesting that when the expression of hormone receptors was positive in ASC, CD44v could play an important role in the transition of LGASC precursor lesions into malignant processes [7]. CD44v, a widely accepted cancer stem cell (CSC) marker in breast cancer, was considered to promote the tumor progression in various cancers [15].…”

“…Though several case reports and case series were published over the years [4,5], ASC remains poorly de ned by immunohistochemistry and its genetic pro le is still unclear [6]. From these limited studies, it appears that ASC differs from its counterparts in this heterogeneous category by its relative clinical indolence, also re ects histologically in its cytomorphology [7]. Under normal conditions, squamous carcinoma (SCC) of the breast must be considered in the differential diagnosis as many reports have included tumors with varying proportions of squamous carcinoma and adenocarcinoma, very few are completely pure without other kind of glandular cell differentiation [8].…”

A Case of Squamous Cell Carcinoma of the Breast with Low-Grade Adenosquamous Carcinoma

“…Low-grade adenosquamous carcinoma (LGASC) of the breast [ 8 , 9 , 10 ] is another rare and distinct subtype of MpBC, being morphologically very similar to LGASC of the skin. MpBC generally shows poorer prognosis than invasive ductal carcinoma and invasive lobular carcinoma [ 4 ].…”