Endosalpingiosis involving axillary lymph nodes of breast cancer : a potential diagnostic pitfall

WANG Yao-hui; PENG Guang-yin; LIU Chun-yang; HAN Mei; ZHANG Yi-fen

doi:10.3969/j.issn.1007-8096.2017.10.010

Abstract：Objective To clarify the clinicopathologic features,differential diagnosis of endosalpingiosis involving axillary lymph nodes of breast cancer.Methods The histological and immunohistochemical features of one case with endosalpingiosis involving axillary lymph nodes of breast cancer and the he histologicaerature were analyzed retrospectively.Results Thirty-six years old woman was diagnosed as invasive breast carcinoma,NOS,Nottingham grade Ⅰ.Thirty-five benign epithelial inclusions were found in axillary lymph nodes(5/27),located in the subcapsule (57％) and capsule (40％) mostly,and the maximum diameters were 86 μm-403 μm.Microscopically,benign epithelial inclusions showed well differentiated glands,with columnar epithelium,and the nuclei were perpendicular to the basement membrane,without obvious architectural and cytologic atypia.The glands were covered with cilia or apocrine columnar epithelium mostly,mixed with a small amount cells with clear cytoplasm,similar to those of fallopian tube.The immunestaining of PAX-8 and WT-1 on columnar epithelial cells was positive,and GATA3 was negative.There were 18 cases in the literature,endosalpingiosis was found in subcapsule and capsule of axillary lymph node,consisted of fallopian tube type epithelium without myoepithelial or basement membrane like material mostly,psammoma body occurred occasionally.ES can be misdiagnosed as cancer metastasis,and can coexist with metastatic cancer,immunohistochemical markers GATA3 (-),Pax-8 and WT1 (+) can make definite diagnosis.Conclusion Endosalpingiosis of the axillary lymph nodes is rare,and the differential diagnosis from lymph node metastatic cancer can be made based on histopathology,immunohistochemical markers,and comparison of original breast cancer.