Lymph node metastasis

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Lymph node metastasis
Diagnosis in short

Lymph node metastasis (colorectal carcinoma). H&E stain.

LM malignant cells foreign to the lymph node - typically subcapsular sinus; morphology dependent on specific cancer
Subtypes dependent on primary tumour - macrometastasis, micrometastasis, isolated tumour cells
LM DDx endometriosis, ectopic decidua, endosalpingiosis, melanocytic nevus, dermatopathic lymphadenopathy, sinus histiocytosis, tumour deposit (dependent on site), pathology of the lymph node - see lymph node pathology and lymphoma
Stains dependent on tumour
IHC dependent on tumour
Gross enlarged lymph node, esp. spherical, white mass with an irregular border +/-extension into surround adipose tissue
Site lymph node - see lymph node pathology

Clinical history +/-suspicion of cancer
Signs +/-large lymph node/mass
Prevalence common - esp. in advanced cancer
Prognosis dependent on specific type of cancer, +/-number of nodes affected
Clin. DDx reactive lymphadenopathy, lymphoma, other benign causes of lymphadenopathy - see lymph node pathology
Treatment dependent on underlying cancer (type and stage)

Lymph node metastasis is cancer that has spread to a lymph node.

General

  • Determination of lymph node status is one of the most common indications for the examination of lymph nodes.
  • It is a good idea to look at the tumour (if available) ...before looking at the LNs for mets.
  • Lymph node metastasis, in the absence of other metastases, often up-stage a cancer from stage II to stage III.

Gross

  • Outside/surface of lymph node:
    • "Large" - size varies by site.‡
      • Neck >10 mm.[1]
    • Shape - round more suspicious than oval.
  • Sectioned lymph node:
    • White firm lesion with irregular border - classic appearance.
    • Non-fatty hilum.[1]

Note:

Microscopic

Features:

  • Foreign cell population - key feature.
    • Classic location: subcapsular sinuses.
  • +/-Cells with cytologic features of malignancy.
    • Nuclear pleomorphism (variation in size, shape and staining).
    • Nuclear atypia:
      • Nuclear enlargement.
      • Irregular nuclear membrane.
      • Irregular chromatin pattern, esp. asymmetry.
      • Large or irregular nucleolus.
    • Abundant mitotic figures.
  • +/-Cells in architectural arrangements seen in malignancy; highly variable - dependent on tumour type and differentiation.
    • +/-Gland formation.
    • +/-Single cells.
    • +/-Small clusters of cells.

Notes:

  1. Cytologic features of malignancy may not be present; some tumours, e.g. gallbladder carcinoma, do not always have overt cytologic features of malignancy.
    • The diagnosis is based on the fact that they are foreign to the lymph node and architecturally consistent with a well-differentiated malignancy.
  2. Lymph node metastases in sarcomas are uncommon; they are seen in <3% of cases.[3]
  3. Fatty lymph nodes (esp. fatty hilus[1]) are less likely to harbor metastases.[4]

DDx - mimics of metastatic disease:

Images

Mimics

Staging

It is customary to record:

  1. The size of the largest lymph node metastasis.‡
    • It is a dictum of the Association of Directors of Anatomic and Surgical pathology[9] that masses >3 cm are matted lymph nodes/confluent lymph nodes or a tumour mass.
  2. The presence/absence of extranodal extension.
    • Tumour grows into the surrounding fat or extends beyond the contour of the lymph node in association with desmoplasia.

Note:

  • ‡ Large size is considered significant at some anatomical sites, e.g. pharynx. It may changes the N stage.

Number of lymph nodes

  • The number of lymph nodes is important for staging, as a small number may lead to stage migration (Will Rogers phenomenon);[10] thus, the number of lymph nodes is often used as a quality measure.

Selected cancers and standard (minimum number of lymph nodes):

  • Stomach cancer - 16 lymph nodes.[10]
  • Colorectal cancer - 12 lymph nodes.
  • Esophageal cancer - no minimum as per UICC/AJCC staging - based on Li et al.[11] - several studies give different numbers (18 lymph nodes Greenstein et al.,[12] 23 lymph nodes Peyre et al.[13]).

See also

References

  1. 1.0 1.1 1.2 Mack, MG.; Rieger, J.; Baghi, M.; Bisdas, S.; Vogl, TJ. (Jun 2008). "Cervical lymph nodes.". Eur J Radiol 66 (3): 493-500. doi:10.1016/j.ejrad.2008.01.019. PMID 18337039.
  2. Sloothaak, DA.; Grewal, S.; Doornewaard, H.; van Duijvendijk, P.; Tanis, PJ.; Bemelman, WA.; van der Zaag, ES.; Buskens, CJ. (May 2014). "Lymph node size as a predictor of lymphatic staging in colonic cancer.". Br J Surg 101 (6): 701-6. doi:10.1002/bjs.9451. PMID 24676735.
  3. Fong, Y.; Coit, DG.; Woodruff, JM.; Brennan, MF. (Jan 1993). "Lymph node metastasis from soft tissue sarcoma in adults. Analysis of data from a prospective database of 1772 sarcoma patients.". Ann Surg 217 (1): 72-7. PMC 1242736. PMID 8424704. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1242736/.
  4. Korteweg, MA.; Veldhuis, WB.; Mali, WP.; Diepstraten, SC.; Luijten, PR.; van den Bosch, MA.; Eijkemans, RM.; van Diest, PJ. et al. (Feb 2012). "Investigation of lipid composition of dissected sentinel lymph nodes of breast cancer patients by 7T proton MR spectroscopy.". J Magn Reson Imaging 35 (2): 387-92. doi:10.1002/jmri.22820. PMID 21972135.
  5. Wu, DC.; Hirschowitz, S.; Natarajan, S. (May 2005). "Ectopic decidua of pelvic lymph nodes: a potential diagnostic pitfall.". Arch Pathol Lab Med 129 (5): e117-20. doi:10.1043/1543-2165(2005)129e117:EDOPLN2.0.CO;2. PMID 15859655.
  6. Corben, AD.; Nehhozina, T.; Garg, K.; Vallejo, CE.; Brogi, E. (Aug 2010). "Endosalpingiosis in axillary lymph nodes: a possible pitfall in the staging of patients with breast carcinoma.". Am J Surg Pathol 34 (8): 1211-6. doi:10.1097/PAS.0b013e3181e5e03e. PMID 20631604.
  7. Biddle, DA.; Evans, HL.; Kemp, BL.; El-Naggar, AK.; Harvell, JD.; White, WL.; Iskandar, SS.; Prieto, VG. (May 2003). "Intraparenchymal nevus cell aggregates in lymph nodes: a possible diagnostic pitfall with malignant melanoma and carcinoma.". Am J Surg Pathol 27 (5): 673-81. PMID 12717252.
  8. Bautista NC, Cohen S, Anders KH (July 1994). "Benign melanocytic nevus cells in axillary lymph nodes. A prospective incidence and immunohistochemical study with literature review". Am. J. Clin. Pathol. 102 (1): 102–8. PMID 8037154.
  9. "Recommendations for the reporting of specimens containing oral cavity and oropharynx neoplasms.". Mod Pathol 13 (9): 1038-41. Sep 2000. doi:10.1038/modpathol.3880188. PMID 11007046.
  10. 10.0 10.1 Deng, JY.; Liang, H. (Apr 2014). "Clinical significance of lymph node metastasis in gastric cancer.". World J Gastroenterol 20 (14): 3967-75. doi:10.3748/wjg.v20.i14.3967. PMID 24744586.
  11. Li, Q.; Wu, SG.; Gao, JM.; Xu, JJ.; Hu, LY.; Xu, T. (Mar 2013). "Impact of esophageal cancer staging on overall survival and disease-free survival based on the 2010 AJCC classification by lymph nodes.". J Radiat Res 54 (2): 307-14. doi:10.1093/jrr/rrs096. PMID 23124992.
  12. Greenstein, AJ.; Litle, VR.; Swanson, SJ.; Divino, CM.; Packer, S.; Wisnivesky, JP. (Mar 2008). "Effect of the number of lymph nodes sampled on postoperative survival of lymph node-negative esophageal cancer.". Cancer 112 (6): 1239-46. doi:10.1002/cncr.23309. PMID 18224663.
  13. Peyre, CG.; Hagen, JA.; DeMeester, SR.; Altorki, NK.; Ancona, E.; Griffin, SM.; Hölscher, A.; Lerut, T. et al. (Oct 2008). "The number of lymph nodes removed predicts survival in esophageal cancer: an international study on the impact of extent of surgical resection.". Ann Surg 248 (4): 549-56. doi:10.1097/SLA.0b013e318188c474. PMID 18936567.