Abstract
Invasive micropapillary carcinoma (IMC) is a cancer histologically characterized by micropapillary neoplastic structures lacking a fibrovascular core and surrounded by clear, empty spaces that mimic lymphovascular invasion. IMC has been reported to affect the breast, urinary tract, lung, and salivary gland. In a recent three-year period from January 2009 to December 2011, a total of 298 cases (320 lesions) of colon cancer were performed surgical resection at our hospital. Of these cases, IMC component was identified in nine cases (nine lesions) (IMC group). In the non-IMC group (289 cases), there were 153 cases of patients who had not experienced metastasis (metastasis-negative group ; Stage 0-II), while there was only one metastasis-negative case in the IMC group. There were 118 metastasis-positive (Stage III-IV) cases in the non-IMC group, versus eight metastasis-positive case in the IMC group. Among 233 cases excluding stage IV cases, recurrence was noted in 25 (11%) out of 227 cases in the non-IMC group, and in five (83.3%) out of six cases in the IMC group. IMC has a high grade malignant potential and has already progressed when it is diagnosed in many cases. The recurrence rate is also high.
