PMC5279906_01
(a) Colonoscopy before chemotherapy showed a circumferential tumor in the sigmoid colon, and biopsy specimens revealed moderately differentiated tubular adenocarcinoma. (b) Colonoscopy after chemotherapy showed an excellent response and the biopsies were negative for cancer cells.
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Colonoscopy showed a circumferential tumor of the sigmoid colon (Fig. 1a). Common Terminology Criteria for Adverse Events (CTCAE) version 4.0, developed during the last course of chemotherapy, but not febrile neutropenia or related infection. Colonoscopy and abdominal CT after systemic chemotherapy demonstrated marked tumor shrinkage, an improved pelvic abscess, and no mesocolon lymph node metastases (Figs. 1d and 2d).
(a-c)Initial computed tomography showed a circumferential thickening of the sigmoid colon wall and involving urinary bladder with a pelvic abscess and urinary air (colovesical fistula). (d) After six courses of chemotherapy showed improvement of pelvic abscess and marked reduction of the tumor.
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Initial computed tomography (CT) and magnetic resonance imaging showed a 4 cm x 4 cm tumor involving the urinary bladder, with a huge pelvic abscess, colovesical fistulas, and many swollen lymph nodes in the mesocolon but no distant metastasis (Fig. 2a-c). Common Terminology Criteria for Adverse Events (CTCAE) version 4.0, developed during the last course of chemotherapy, but not febrile neutropenia or related infection. Colonoscopy and abdominal CT after systemic chemotherapy demonstrated marked tumor shrinkage, an improved pelvic abscess, and no mesocolon lymph node metastases (Figs. 1d and 2d).
PET-CT showed the primary tumor in the sigmoid colon.
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Positron emission tomography-CT confirmed the primary tumor in the sigmoid colon and the absence of distant metastasis (Fig. 3).
Microscopic findings with H&E showed the tumor had been almost replaced fibrous tissue, with only two glands cancer cells left in the submucosa.
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On microscopic examination, the specimen resected following therapy was replaced almost completely with fibrous tissue, with only a few degenerated tumor glands remaining in the submucosal layer, and no lymph node metastases (Fig. 4a-b).