title: Isolated retromammary lymph node metastasis of breast cancer without axillary lymph node involvement: a case report with a false-negative sentinel lymph node biopsy.
abstract: A 54-year-old woman visited our hospital with a palpable tumor in her left breast, which was diagnosed as invasive ductal carcinoma. Breast-conserving surgery was performed, in association with a sentinel lymph node (SLN) biopsy and back-up dissection of the axillary lymph nodes. One dyed axillary lymph node with high radioactivity was defined as an SLN, and intraoperative frozen-section analysis of the SLN was negative for metastasis. The final pathological diagnosis of the tumor was invasive ductal carcinoma, and one small lymph node, located in the retromammary space, just under the tumor, was positive for metastasis. The backup axillary lymph nodes were not metastatic. This patient was diagnosed false-negative by SLN biopsy, despite being positive for retroMLN metastasis. It should be recognized that retroMLNs are difficult to detect preoperatively, or intra-operatively, using dye or radiocolloid, if they are located in the post-tumoral retro-mammary space. RetroMLNs may be a pitfall in SLN biopsies.
authors.affiliation: Department of Thoracic and Visceral Organ Surgery, Graduate School of Medicine, Gunma University, 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan. rokutan@med.gunma-u.ac.jp
authors.forename: Nana
authors.initials: N
authors.lastname: Rokutanda
authors.forename: Jun
authors.initials: J
authors.lastname: Horiguchi
authors.forename: Yukio
authors.initials: Y
authors.lastname: Koibuchi
authors.forename: Rin
authors.initials: R
authors.lastname: Nagaoka
authors.forename: Ayako
authors.initials: A
authors.lastname: Sato
authors.forename: Hiroki
authors.initials: H
authors.lastname: Odawara
authors.forename: Hideaki
authors.initials: H
authors.lastname: Tokiniwa
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Iino
authors.forename: Junko
authors.initials: J
authors.lastname: Hirato
authors.forename: Izumi
authors.initials: I
authors.lastname: Takeyoshi
mesh_terms: D001365:Axilla; D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000556:secondary* / Q000601:surgery; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009367:Neoplasm Staging; D021701:Sentinel Lymph Node Biopsy