Abdominal Wound Metastasis after Laparoscopic Surgery of Gastrointestinal Stromal Tumor

Abstract

Surgical resection is the mainstay treatment for gastrointestinal stromal tumors (GISTs). Laparoscopic surgery can be considered for treating these tumors since their biologic behavior lends them to curative resection without requiring large margins or extensive lymphadenectomy. Despite complete resection, GISTs frequently recur specifically in the liver and peritoneum. Although they occur in other upper gastrointestinal malignancies, recurrences of GISTs at the port sites after laparoscopic surgery have rarely been reported. We describe here a patient with abdominal wound metastasis after laparoscopic surgery for GIST.

INTRODUCTION

Gastrointestinal stromal tumors (GISTs) are a rare mesenchymal neoplasms of the digestive tract with an estimated annual incidence of 10-20 cases per one million inhabitants. GISTs probably arise from precursor cells of the interstitial cells of Cajal.^1,2 The stomach is the most common site of involvement, followed by the small intestine, colon, rectum and esophagus.³ Clinical presentation is usually characterized by gastrointestinal bleeding, abdominal pain, weight loss and a palpable mass. GISTs have traditionally been treated by surgery. The results of a simple surgical resection with clear margins were comparable to those of a radical resection. Therefore until recently simple resectional surgery remained the mainstay of treatment. To our knowledge, this case of a port site metastasis following laparoscopic surgery for a malignant GIST would be only the third case reported in the literatures. We report this case with a review of the relevant literatures.

CASE REPORT

A 69-year-old woman was followed up submucosal tumor and the tumor's sized had recently been noted to be increased. Endoscopic examination showed a 4×4 cm sized round mass with intact mucosa and central ulceration on lesser curvature of the lower body (Fig. 1). She underwent an endoscopic ultrasound, which revealed a 4 cm-sized hypo or mixed echoic mass with central ulceration in the muscularis propria of the lesser curvature of the lower body (Fig. 2). This was consistent with a GIST. Computed tomographic (CT) scan showed an exophytic mass in the body of the stomach along the lesser curvature. She underwent a laparoscopic wedge resection and biopsy result was GIST and the resectional margin was positive in frozen section biopsy, she then underwent laparoscopic distal gastrectomy with gastrojejunostomy. Proximal and distal surgical margin was negative. The tumor size was 4×4 cm and Mitotic count (MC) was more than 5 of 50 high power fields (HPFs) with c-Kit (+). Thirty five months after surgery, she visited our hospital because of a painful and palpable subcutaneous nodule at the scar of the periumbilical trocar incision.

Fig. 1.

Endoscopic findings showing a 4.0×4.0-cm mass with central ulceration in the lesser curvature of the lower body.

Fig. 2.

Endoscopic ultrasound findings showing a 4-cm hypoechoic or mixed-echoic mass with central ulceration in the muscularis propria of the lesser curvature of the lower body.

A CT scan of abdomen showed a 1×1 cm sized well enhanced mass between the internal oblique muscle and the transversalis fascia at the scar of the periumbilical trocar incision (Fig. 3).

Fig. 3.

Contrast-enhanced abdominal CT reveales a 1-cm mass in the right abdominal wall between the internal oblique muscle and the transversalis fascia (arrow).

An ultrasound guided gun biopsy of abdominal wall mass was performed (Fig. 4). It was removed by excisional resection. The biopsy result was GIST (Fig. 5). The patient is currently asymptomatic and has received 400 mg/d of imatinib mesylate for 3 years.

Fig. 4.

Ultrasound-guided gun biopsy of the abdominal wall mass is performed.

Fig. 5.

Microscopic finding of the resected abdominal wall mass. (A, B) Tumor cells showing fascular proliferation of spindle-shaped cells (A, H&E stain, ×200; B, H&E stain, ×400). (C, D) Histochemical study showing positive staining for CD34 and c-Kit.

DISCUSSION

GISTs are a rare type of nonepithelial, mesenchymal neoplasm of the gastrointestinal tract. This tumor accounts for approximately 1% of all malignant GI tumors, and it arises from the Cajal's interstitial cells.^1,2 They can occur anywhere in the gastrointestinal tract and they most commonly arise in the stomach.³

The current definitive treatment for GIST of the stomach is complete resection.⁴ Since GIST tends to grow out of the primary organ, and they do not diffusely infiltrate it, wedge resection of stomach is considered as an adequate treatment.⁵ The laparoscopic approach also allows full-thickness resection of the stomach wall containing the tumor.^3,6

GIST has a highly variable clinical course and recurrent disease sometimes develops despite curative treatment.⁴ Most metastases arise in the liver and peritoneal cavity, and this is caused by hematogenous spread and peritoneal seeding. Extraabdominal disease in the absence of peritoneal involvement is rare.⁷

Because of the high recurrence rates after surgery for GIST, imatinib mesylate, a small-molecule kinase inhibitor, has proven useful in the treatment of recurrent or metastatic GIST and is now being tested as an adjuvant for medium-and high risk patients.⁸

In one study, the GISTs that were <50 mm in size and that were not accompanied by other diseases can be treated successfully by laparoscopic surgery.⁹ But the National Comprehensive Cancer Network (NCCN) and the European Society of Medical Oncology (ESMO)^5,10 recently recommended that "laparoscopic or laparoscopic-assisted resection may be used for small (<2 cm) GISTs when the risk of intraoperative tumor rupture is low."

To our knowledge, there is only two previously documented case of port site metastasis following laparoscopy for a gastrointestinal stromal tumor.^11,12 Although laparoscopic surgery has many advantages, reports of recurrent disease at the laparoscopic port sites have raised concerns in many surgical specialties.^13-15 It is not known whether a recurrence at a port site is a clinically relevant event or whether it occurs primarily as a results of advanced disease.

Three factors that relate specifically to laparoscopic surgery may be important in the development of the port site recurrence.¹⁶ First, the repeated passage of the instruments through the port may bring exfoliated cells adherent to the instrument into close proximity with the port site. Second, increased manipulation of the tumor may lead to increased exfoliation of tumor cells. Finally, there are the effects of pneumoperitoneum. Clumps of whole cells have recently been collected in the smoke produced by electrocoagulation at laparoscopy.¹⁷ As this gas escapes under pressure around the port sites, these clumps of tumor cells may be seeded into the wound.

In conclusion, we described here a rare case of a patient with abdominal wound metastasis after laparoscopic surgery for GIST. Laparoscopic surgery for GIST should be done prudently and considered for cases of small sized GISTs because of the risk of tumor cell seeding and recurrence at the laparoscopic port site.