Abstract:
We would like to present a only case study: However, our important findings might lead to help the interpretations of “tumour microenvironment (TME)”.
We herein presenting about 70-year-old female. She presented with a palpable mass in the upper inner quadrant of the right breast, noticed approximately 3 months before. Mammographic screening revealed an abnormality. Hence, she visited a nearby clinic.
1 month later, a core needle biopsy (CNB) suggested “invasive breast carcinoma”, then, she referred to our hospital for further examinations and treatments.
Breast MRI revealed a 14 × 21 × 31 mm mass in the right AC, including 1 small daughter nodule. The lesion exhibited restricted signal on diffusion-weighted imaging as well as ADC map, suggesting malignancy. Consequently, total mastectomy was performed.
Grossly, the surgical specimen demonstrated a continuous lesion in which papillary ductal carcinoma in situ (Pap-DCIS) with mucin production that surrounded a mucinous carcinoma of micropapillary type (IMP-MC). The IMP-MC component showed increased cellular density with “random pattern” of membrano-cytoplasmic MUC1 positivity. Both Pap-DCIS and IMP-MC exhibited positive for Alcian Blue, demonstrated with extremely reduced MUC2 expression, and revealed focal positivity for Synaptophysin. Moreover, β-catenin and E-cadherin were positive but reduced staining compared to the surrounding normal ducts. Both lesions displayed “heterogeneous baso-lateral staining patterns with unclear directional polarity or loss”. In the current case, we hypothesized some types of IMP-MC might be resembling pap-DCIS of “disruption of cellular polarity” rather than “reverse polarity” by our observations of our immunohistochemical profiles including cell adhesion molecules (CAMs). Hence, our data might be suggestive of this “Low-grade MC” might not through EMT (epithelial mesenchymal transition) pathway but through “non-EMT pathway (clustered migration theory)”. Furthermore, we would like to hypothesize “CAMs” might play a key role for maintaining “bilayer structure of luminal-myoepithelial cell communication”.
Based on these findings, we report the immunohistochemical characteristics of this “IMP-MC of TME” with a literature review emphasizing on the role of CAMs as well as “bilayer structure” of the pathogenesis with comparing “TCGA Classification”.
