Tumour deposit
A tumour deposit is a microscopic or macroscopic tumour nodule in the lymphatic drainage bed of the (primary) tumour. The term is applied in colorectal adenocarcinoma and has also been described in gastric cancer.[1]
It is also known as discoutinuous extramural extension and peritumoural deposit.
Conceptually, tumour deposits are like the in-transit metastases of malignant melanoma[2] and dermatopathology; however, it is important to note that on a practical level the specific (morphologic/clinical) definitions of tumour deposit and in-transit metastasis are different.
General
Significance:
- Poor prognosticator.
- Can be understood as a type of invasive front/border, e.g. well-circumscribed border versus infiltrative border.[3]
Definition
Definition - TNM/AJCC 7th edition for colorectal cancer:[4]
- Microscopic or macroscopic nodule in the lymphatic drainage bed of the tumour.
- No standardized distance (from tumour) criteria are defined.[3]
- No findings suggestive of it being a lymph node replaced by tumour:
- No significant lymphoid tissue.
- Irregular contour.
- Round nodules of tumour are considered lymph nodes that are replaced by tumour.
Notes:
- The definition of tumour deposit has changed significantly between the TMN/AJCC fifth, sixth and seventh editions.[4]
- Lesions that are not in the drainage bed of the tumour are metastatic disease, pM1b.
Ueno criteria
Ueno et al. propose that a tumour deposit is either:[3]
- >=2 mm from the tumour front.
- >=2 mm (radially) from the deepest aspect of the muscularis propria, if the tumour is not present in the plane of section.
Staging
Staging implications in colorectal cancer:
- Tumour deposits are not counted as (positive) lymph nodes[4] and in the context of positive lymph nodes do not change the N stage.
- If no positive lymph nodes are present, the N stage is pN1c.
- The T stage is not affected by tumour deposits.[4]
See also
References
- ↑ Lee, HS.; Lee, HE.; Yang, HK.; Kim, WH. (May 2013). "Perigastric tumor deposits in primary gastric cancer: implications for patient prognosis and staging.". Ann Surg Oncol 20 (5): 1604-13. doi:10.1245/s10434-012-2692-9. PMID 23184289.
- ↑ Puppa, G.; Ueno, H.; Kayahara, M.; Capelli, P.; Canzonieri, V.; Colombari, R.; Maisonneuve, P.; Pelosi, G. (Mar 2009). "Tumor deposits are encountered in advanced colorectal cancer and other adenocarcinomas: an expanded classification with implications for colorectal cancer staging system including a unifying concept of in-transit metastases.". Mod Pathol 22 (3): 410-5. doi:10.1038/modpathol.2008.198. PMID 19136930.
- ↑ 3.0 3.1 3.2 Ueno, H.; Hashiguchi, Y.; Shimazaki, H.; Shinto, E.; Kajiwara, Y.; Nakanishi, K.; Kato, K.; Maekawa, K. et al. (Oct 2013). "Peritumoral deposits as an adverse prognostic indicator of colorectal cancer.". Am J Surg. doi:10.1016/j.amjsurg.2013.04.009. PMID 24112678.
- ↑ 4.0 4.1 4.2 4.3 Nagtegaal, ID.; Tot, T.; Jayne, DG.; McShane, P.; Nihlberg, A.; Marshall, HC.; Påhlman, L.; Brown, JM. et al. (Jun 2011). "Lymph nodes, tumor deposits, and TNM: are we getting better?". J Clin Oncol 29 (18): 2487-92. doi:10.1200/JCO.2011.34.6429. PMID 21555695.