Shape Is Not Associated With the Origin of Pericolonic Tumor Deposits

Abstract

Pericolonic tumor deposits (PTDs) are associated with an adverse outcome in colorectal cancer. According to the International Union Against Cancer they are classified as N1 or V1/V2 depending on their shape. This recommendation, however, is not well supported by the literature. To elucidate the origin of PTDs, we performed a histomorphologic study of 69 PTDs, which were found in 7 of 21 colorectal specimens using the whole-mount step-section technique. Depending on the origin, the nodules were classified as venous invasions, lymphatic invasions, nerve sheath infiltrations, free PTDs, and continuous growth in 18 (26%), 3 (4%), 6 (9%), 34 (49%), and 8 (12%) of 69 PTDs, respectively. Polycyclic and oval-round shapes were identified in all categories. Continuous growth was found only within the inner third of the adhering fat, whereas the other morphologic features were found in all regions. The data of this study do not support PTD classification on the basis of their shape.

TNM staging system of colorectal carcinoma: surgical pathology of the seventh edition

“…The remaining types of TDs are the most intriguing ones, those with no evident association with any structure. Enhanced pathologic analysis (EPA) in these selected cases, with examination of multiple levels ( Figure 13aec) has been proved to assess the actual nature of TDs in many cases, 166,167,170 and the use of special stains may be helpful. 167 Accordingly, when a TD is near the intestinal wall, the review of multiple sections may even exclude the presence of a TD, suggesting a continuous growth instead, 164 thereby assigning the T category (Figure 14aeb).…”

Frequency of therapy-relevant staging shifts in colorectal cancer through the introduction of pN1c in the 7th TNM edition

“…In particular, the minimal distance of the tumour deposits from the primary tumour is not defined. Ueno et al [25] used a 5 mm distance rule for the definition of TDs, probably to rule out continuous tumour growth, underlying 12% of TDs according to Wü nsch et al [8]. A prognostic difference between 'continuous TDs' and 'discontinuous TDs', however, has not been investigated so far.…”

“…Their first descriptions date back to the mid thirties of the last century [6,7], when they were considered soft tissue metastases resulting from vascular tumour infiltration. In fact, most TDs present a local metastatic spread via blood and/or lymphatic vessels, only a minority of these lesions originate from nerve sheath infiltrations or demonstrate continuity with the primary tumour in serial sections [8,9].…”

Reply to “Ex Vivo Sentinel Lymph Nodes in Pathological Staging of Node-Negative Colorectal Carcinoma,” by Peparini and Chirletti

“…We investigated the origin of tumor deposits in a recently published study. 3 In 50% of the deposits, a distinct origin (continuous growth, venous, lymphatic, nerve sheath invasion) could be found in corresponding step sections. Neither size nor shape of the satellites was associated with their origin.…”