- Macrometastases: > 2mm
- Micrometastases: 2 mm or less
- Isolated tumor cells: 0.2 mm or less
- Presence of axillary lymph node metastases is the most important prognostic factor for disease free and overall survival, and important for determining treatment
- Presurgical staging of axillary nodes (ultrasound with FNA) is increasingly popular (Cancer 2008;114:89)
- Axillary nodal dissection may not be indicated if negative sentinel node examination, even if false-negative (Breast Cancer 2010;17:9, Eur J Cancer 2009;45:1381)
- Occult metastases (identified retrospectively by step-sectioning and immunohistochemical staining) are an independent predictor of disease-free survival, but not overall survival, in node-negative patients, particularly if > 0.5 mm (Am J Surg Pathol 2002;26:1286); recent study reports no prognostic significance of occult metastasis in early stage breast cancer (Cancer 2012;118:1507)
- Significance of micrometastases is controversial (Arch Pathol Lab Med 2009;133:869)
- Clearing solutions, such as ethanol, diethyl ether, Carnoyís solution (Chin Med J (Engl) 2007;120:1762), glacial acetic acid and formalin may identify additional lymph nodes (Am J Surg Pathol 1997;21:1387, Arch Pathol Lab Med 2001;125:642)
- Neoadjuvant chemotherapy may be associated with identification of fewer lymph nodes (J Am Coll Surg 2008;206:704), but see Am J Surg 2009;198:46
- Regional lymph nodes are:
- Axillary (ipsilateral), subdivided as follows (image):
- Level I (low axilla): lateral to the lateral border of pectoralis minor muscle
- Level II (mid axilla): between medial and lateral borders of pectoralis minor muscle, plus the interpectoral (Rotter's) lymph nodes
- Level III (apical axilla): medial to the medial margin of the pectoralis minor muscle, including those designated as apical, excluding those designated as subclavicular or infraclavicular
- Infraclavicular (subclavicular, ipsilateral)
- Internal mammary (ipsilateral): lymph nodes in the intercostal spaces along the edge of the sternum in the endothoracic fascia
- Supraclavicular (ipsilateral)
- Axillary (ipsilateral), subdivided as follows (image):
- Side effects of axillary nodal dissection include lymphedema, shoulder restriction, numbness, weakness and pain syndromes (Cancer J 2008;14:216)
- Dissection of the brachial, acromiothoracic, humeral, Rotter's and scapular lymph nodes is recommended for proper staging (J Egypt Natl Canc Inst 2011;23:25)
- 52 year old woman with submental lymph node metastasis from invasive ductal breast cancer (Arch Gynecol Obstet 2012;285:1153)
- 55 year old woman with DCIS arising in intraductal papilloma in axillary lymph node (Arch Pathol Lab Med 2008;132:1940)
- 58 year old woman with melanoma and breast ductal carcinoma metastasizing to same node (Int Semin Surg Oncol 2006;3:32)
- 82 year old woman with sclerosing adenosis in axillary lymph node (Arch Pathol Lab Med 2008;132:1439)
Images hosted on PathOut server:
Courtesy of Mark R. Wick, M.D.
Scroll to see all images:
Images hosted on PathOut server:
Courtesy of Mark R. Wick, M.D.
False positives (i.e. not metastatic breast carcinoma):
Intramammary lymph node
Metastatic ovarian serous papillary adenocarcinoma
Left: heterotopic glands with structure of mammary lobule; right: myoepithelial cells (arrows) and basement membrane are present
Lactational histiocytosis
Clusters of nevus cells have indistinct cell borders and small uniform nuclei, and are S100+ (as are histiocytes)
Hemangioma
Tattoo pigment
Dilated dermal
vascular channels with
prominent endothelial cells
Hyperkeratosis,
thickened dermis with
edema, elastosis, fibrosis,
congested capillaries
(arrow) and lymphocytes
Pseudoepitheliomatous
hyperplasia, hyperkeratosis,
dilated dermal vascular channels
Images hosted on other servers:
Axillary nodal metastases
Metastatic breast carcinoma and melanoma
Subcapsular metastasis: H&E and keratin
Metastatic tumor (A) with adjacent histiocytes (B)
Various images
Metastatic carcinoma,
benign inclusions and nevus cells
False positives (i.e. not metastatic breast carcinoma):
DCIS arising in intraductal papilloma
Sclerosing adenosis
Benign epithelial inclusions - Fig 1: CK 5/6+; Fig 2: p63+
Histiocytes (FNA)
Lipogranulomatosis due to triglyceride-filled breast implant
Images hosted on other servers:
Various images
- Benign transport after prior breast biopsy (Am J Clin Pathol 2000;113:259)
- Ectopic breast tissue (Breast Cancer 2007;14:425)
- Muciphages: resemble signet ring carcinoma, associated with prior surgery or lactation, Alcian blue+, CD68+, Mac387+, keratin- (Am J Surg Pathol 1998;22:545)
- Mullerian type epithelial inclusions: have myoepithelial cells which are p63+ and smooth muscle myosin+ (Arch Pathol Lab Med 2004;128:361, Arch Pathol Lab Med 1995;119:841, Am J Clin Pathol 2008;130:21)
- Nevus cells (Am J Clin Pathol 1994;102:102, Am J Surg Pathol 2003;27:673, Arch Pathol Lab Med 1985;109:1044)
