A case of postoperative hepatic granuloma presumptively caused by surgical staples/clipping materials

Abstract

A 66-year-old man with postsigmoidectomy status for colon cancer received laparoscopic partial hepatectomy due to a hepatic mass with employing titanium clips were for a vascular clamp. Histological examination showed liver metastasis from sigmoid colon cancer. Twenty-nine months after the partial hepatectomy, a mass developed on the stump at the hepatic resection. Laparoscopic left lateral segmentectomy was conducted under suspicion of cancer recurrence and an automatic titanium stapling device was used. The macroscopically cut surface of the liver showed a grey-white solid nodule measuring 23 x 20 mm and involving metal clips. The nodule was consistent with granuloma microscopically. Twenty-three months after the segmentectomy, a mass reappeared on the hepatic radial margin and an open left lateral hepatic lobectomy was performed because of its growth tendency. Histopathological examination revealed granuloma similar to the previous instance. Since these nodules formed a granulomatous lesion surrounding metal staples/clips and evidence of caseous necrosis was lacking, granuloma due to surgical staples/clips was suspected. Sporadic case reports of postoperative pulmonary granuloma at the staple line have been published previously, but there are no articles detailing a case involving hepatic granuloma. We present our case as the first report of postoperative staple-line hepatic granuloma.

Fig. 1

Contrast-enhanced CT scan. A non-enhanced mass (arrow) measuring 35 mm in length at the wedge from the cut stump of the hepatic resection

Fig. 2

Histopathologic features. An overview loupe (hematoxylin-eosin: HE). The nodule had necrotic tissue in the center (*) surrounded by fibrous tissue (†) and circular formation of granuloma on the boundary between the hepatocytes and fibrous tissue (‡)

Fig. 3

Histopathologic features. a Necrotic tissue (*, HE x 1000). b Silver staining revealed the necrotic tissue preserved the structure of the hepatic cell plate and involved the portal tract, suggesting that it is a result of necrosis of the hepatocytes (*, silver staining x 1000). c Fibrous tissue (†, HE x 1000). d Fibrous tissue (†, silver staining x 1000). e The outermost layer was the band of granuloma comprising macrophages of epithelioid feature cells, lymphocytes and plasma cells with some infiltration of eosinophils forming a distinct boundary between normal hepatic tissue and the necrotic region. Multinucleated giant cells were present but not prominent (‡, HE x 1000). f The outermost layer (‡, silver staining x 1000)

Fig. 4

Immunohistochemistry (x 400). a HE. b CD68. c CD 3. d CD 20

Fig. 5

Macroscopic features. a A grey-white solid nodule measuring 45 x 38 mm in the resected liver. b Staple needles in the central portion of the nodule (arrows). c Micro CT