Significance of Histologic Criteria for the Management of Patients with Malignant Colorectal Polyps and Polypectomy

Abstract

Locally excised malignant polyps without unfavourable histologic signs may not need further surgical treatment; for all other malignant polyps an ensuing bowel resection is recommended.

Pathology of Staging of Early Colorectal Lesions During Surveillance Programmes

“…Generally, malignant colorectal polyps are divided into high and low risk lesions. High risk malignant polyps were defined as having one of the following: incomplete polypectomy, an involved resection margin, lymphatic or venous invasion, or are poorly differentiated histologically (Netzer et al, 1997). Adverse outcome in a malignant colorectal polyp was defined as residual cancer in a resection specimen and local or metastatic recurrence in the follow up period (Netzer et al, 1998).…”

“…Cancer near the margin has been variously defined as cancer cells 1mm or less from the transacted margin, (Cooper et al, 1995) cancer cells 2mm or less from the transacted margin, (Netzer et al, 1997;Volk et al, 1995) and cancer within the diathermy and/or within one high-power field of the diathermy (Morson et al, 1984;Ueno et al, 2004b). However, most studies showed that the presence of cancer near the transected margin has the same clinical significance as cancer at the actual margin (Cooper et al, 1995;Hackelsberger et al, 1995;Netzer et al, 1997). Presently, there is no consensus on what represents a 'negative margin'.…”

“…Presently, there is no consensus on what represents a 'negative margin'. A negative margin has been defined as one in which cancer is not within the actual diathermy, (Morson et al, 1984) more than one high-power field from the diathermy, greater than 1mm from the margin (Cooper et al, 1995) and more than 2mm from the margin (Netzer et al, 1997;Seitz et al, 2004). Incomplete local excision is not a judgement based on histology alone but a decision made jointly by the endoscopist and pathologist (Cooper, 2007).…”

Welcher endoskopisch abgetragene Kolonpolyp bedarf einer zusätzlichen onkochirurgischen Kolonresektion?

“…Unter Einbeziehung chirurgischer Serien werden sogar 9±11% angegeben [7, 11±16]. In einer eigenen Serie fanden wir bei u È ber 6 600 Patienten mit einer Koloskopie bei 0,5% einen malignen Polypen, was einem Anteil von 4,5% der Patienten mit adenomato È sen Polypen entsprach [9]. Die meisten dieser malignen Polypen waren im Rektosigmoidbereich lokalisiert, was mit anderen Studien korreliert [10].…”

“…Obwohl diese Erkenntnis heute akzeptiert wird, sind die Ansichten u È ber die prognostisch gu È nstigen histologischen Kriterien unterschiedlich [7, 14, 20±27]. Wir haben deshalb in zwei klinikeigenen Studien die Relevanz der verschiedenen histologischen Kriterien auf den weiteren Verlauf der Patienten untersucht [9,10]. Dabei wurde ein ungu È nstiger Verlauf als noch vorhandenes Karzinomgewebe bei einer allfa È lligen Operation oder das Auftreten eines Lokalrezidivs, von Lymphknoten-oder anderen Metastasen im weiteren Follow-up definiert [9,10].…”