title: Sarcoid reaction in the spleen after sigmoid colon cancer resection: a case report.
abstract: BACKGROUND
  A sarcoid reaction is a phenomenon characterized by histologically proven granulomatous lesions without evidence of sarcoidosis. This pathology is a benign tumor itself, but several reports have described sarcoid reactions accompanying malignant tumors. Sarcoid reactions occur in various cancers, such as skin, lung, ovary, stomach, and breast cancers. However, only a few published reports have described sarcoid reactions in patients with colorectal cancer.
  
  
  METHODS
  A 76-year-old woman underwent laparoscopic sigmoidectomy for sigmoid colon cancer. The postoperative follow-up computed tomography and 18-fluorodeoxyglucose positron emission tomography-computed tomography findings were suspicious for splenic metastasis of the sigmoid colon cancer. The patient then underwent laparoscopic splenectomy. Histopathological examination of the resected lymph nodes and spleen showed a non-caseating epithelioid cell granuloma. The patient was diagnosed with a sarcoid reaction.
  
  
  CONCLUSIONS
  To our knowledge, this is the first report of a sarcoid reaction in the spleen and regional lymph nodes after colon cancer resection. The effect of a sarcoid reaction on the prognosis in patients with colorectal cancer has not been fully determined because of the small number of such cases. Further analyses involving a larger number of cases are necessary to evaluate the relationship between sarcoid reactions and prognosis in patients with colorectal cancer. We herein present an extremely rare case of a sarcoid reaction in the spleen and regional lymph nodes.
authors.affiliation: Department of Surgery, Minami Osaka Hospital, Osaka, Japan. sur167@osaka-med.ac.jp.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Shima
authors.affiliation: Department of Surgery, Minami Osaka Hospital, Osaka, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Department of Surgery, Minami Osaka Hospital, Osaka, Japan.
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Katsuragi
authors.affiliation: Department of Surgery, Minami Osaka Hospital, Osaka, Japan.
authors.forename: Nagahisa
authors.initials: N
authors.lastname: Fujio
authors.affiliation: Department of Surgery, Minami Osaka Hospital, Osaka, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Nakatani
authors.affiliation: Department of Pathology, Minami Osaka Hospital, Osaka, Japan.
authors.forename: Yasutsugu
authors.initials: Y
authors.lastname: Kobayashi
authors.affiliation: Department of Surgery, Minami Osaka Hospital, Osaka, Japan.
authors.forename: Tadayuki
authors.initials: T
authors.lastname: Hida
keywords: Colon cancer; Sarcoid reaction; Spleen