Internal mammary lymph node drainage patterns in patients with breast cancer documented by breast lymphoscintigraphy.
BACKGROUND
Metastases to internal mammary lymph nodes (IMN) may occur in patients with breast cancer and may alter treatment recommendations. The purpose of this study was to identify the frequency of IMN drainage in patients undergoing breast lymphoscintigraphy and sentinel lymph node dissection (SLND).


METHODS
The combined technique of peritumoral injection of radiocolloid and Lymphazurin blue for SLND was performed on 220 patients. All patients underwent preoperative lymphoscintigraphy before SLND. Lesion location by quadrant included: 110 upper outer (UOQ), 49 lower outer (LOQ), 30 upper inner (UIQ), 24 lower inner (LIQ), and 7 central.


RESULTS
Drainage to any nodal basin was observed in 184 of 220 patients (84%). IMN drainage was documented in 37 of 220 (17%) of patients. IMN drainage without evidence of axillary drainage occurred in 2 of 220 patients(1%). Drainage to the IMN based on quadrant location of the lesion was as follows: UOQ, 10%; LOQ, 27%; UIQ, 17%; LIQ, 25%; and central, 29%.


CONCLUSIONS
Internal mammary lymph node drainage shown by breast lymphoscintigraphy is common. Tumors in all quadrants may drain to IMNs, although drainage is significantly more common from quadrants other than the UOQ. Further studies are needed to determine whether lymphoscintigraphy drainage patterns identify patients at the highest risk for IMN metastases who may benefit from radiotherapy.
Byrd
D R
DR
Department of General Surgery, University of Washington Medical Center, Seattle 98195, USA. byrd@u.washington.edu
Dunnwald
L K
LK
Mankoff
D A
DA
Anderson
B O
BO
Moe
R E
RE
Yeung
R S
RS
Schubert
E K
EK
Eary
J F
JF
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D018567:Breast Neoplasms, Male / Q000000981:diagnostic imaging / Q000473:pathology; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000473:pathology*; D002278:Carcinoma in Situ / Q000000981:diagnostic imaging / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000000981:diagnostic imaging / Q000473:pathology; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D021701:Sentinel Lymph Node Biopsy / Q000379:methods