Abstract:
Herein, we would like to present the case of about 80-year-old female. Her chief complaint was bloody nipple discharge in the left breast. She came to our hospital for thorough examination and treatment. Ultrasonography detected intraductal carcinoma of about 10mm spreading. The discharge specimen of CEA data was as high as 300. Subsequently, biopsy was performed and diagnosed “ductal carcinoma in situ” (DCIS). Hence, left mastectomy was done. Pathologically, total size of 20X20X15mm of low-grade DCIS and invasion was less than 1mm. Histological subtype was “micro-invasive carcinoma of type B mucinous carcinoma”. In situ lesions demonstrated “solid papillary carcinoma” with widely disrupted myoepithelial cell (MEC) layer and some fibrovascular-cores were infarcted. Invasive lesion was “mucinous carcinoma type-B”. Besides, ER: 99%, PgR: 90%, HER2: 0, Ki-67-index: 5%. Hence, luminal-A subtype was considered. MECs revealed heterogenous or complete loss by CK5/6. And invasive cell populations revealed ER strong-positive same as in situ lesions. Previous report indicated generally, when DCIS changed to invasive lesions, the latter populations are ER negative of stem-like cells. However, in our case, ER positive invasive cell population might be related to good prognosis compared to high-grade one.
Furthermore, our aim is to detect the origin of the “nipple tumors”. Because, “terminal duct lobular unit (TDLU)” which is thought the origin of breast tumors in general. However, TDLU are lacking in the nipple as commonsense. Hence the nipple tumors including “nipple adenoma” and other tumors of origin is unkown in recent WHO classification. We tried to discover the origin of “nipple tumor” using selective combination of immunohistochemistry (IHC). Previous reports indicated CK15 is well known to epithelial stem marker and CK19 is known to “low molecular weight cytokeratin (LMWCK)”. CK5/6 is known to “high molecular weight cytokeratin (HMWCK)” and “estrogen receptor (ER)” expression is thought important role for preventing genes and chromosomal instability. In our results, we would like to hypothesize that stem-like cells are not rundam distribution but in “peri-infarcted fibrovascular-core” of continuous IHC sections. The stem-like cell population showed “ER-/CK15+/CK19+/CK5/6+“ IHC feature. It might be considered stem-like/progenitor-like cell exists in the most hypoxic area of infarcted fibro-vascular core as “peri-infarcted niche” like as previous reports of “peri-necrotic niche” of brain tumors. According to our results, it might be thought that hypoxic microenvironment might contribute to tumorigenesis as well as sustaining tumor survival. We think that our case might contribute to discover the origin of “tumors of the nipple”. Previous reports indicated stem-like cells are existed in “collecting duct” of the normal nipple. Our results might concordant of this theory. Also, many case reports of piling up might be thought important for understanding nipple tumors.
Audience Take Away Notes:
- First, audience would learn tumor of the nipple is special feature and importance of the stem-like cells
- Second, audience would learn the association of ischemic microenvironment and tumorigenesis
- Third, audience would learn the microenvironment of tumorigenesis is important for pathogenesis of tumor histology
- To understanding tumor microenvironment of nipple tumors would help clinically for including targeted therapy or better solution in the future for knowing the importance of tumor microenvironment as well as tumorigenesis by our pathological knowledge. We believe that understanding of the pathogenesis of nipple tumors might contribute to molecular science for detecting the targeted molecule
