Postsurgical radiation therapy for gastric carcinosarcoma with c-kit expression: a case report

Abstract

Gastric carcinosarcomas are rare morphologically biphasic tumors, consisting of carcinoma and sarcoma components, with a poor clinical course. Here we report the case of a 70-year-old man with advanced Borrmann type III carcinosarcoma arising from the upper body of the stomach with extensive lymph node metastasis who underwent a total, but palliative, gastrectomy. Histology showed the tumor consisted of a biphasic structure of tubular adenocarcinoma and spindle cell sarcoma. Immunohistochemistry revealed sarcoma cells expressing c-kit (CD117) and CD34, which are criteria for gastrointestinal stromal tumors. Nine months after the surgical operation, tumor metastases had extended to the hepatohilar, retroperitoneal and mediastinal lymph nodes. Radiation therapy of 50 Gy markedly decreased the size of each of these nodes and reduced the risk of respiratory complications and jaundice. However, the patient died of respiratory failure due to bronchopneumonia with multiple lung metastases 22 mo after resection. Autopsy revealed severe necrosis in most of the lymph nodes with tumor metastases. Radiation therapy combined with gastrectomy should be considered to improve survival in patients with gastric carcinosarcomas that express c-kit.

Keywords: C-kit; CD34; Gastric carcinosarcoma; Gastrointestinal stromal tumor; Radiation therapy.

Figure 1

Tumor presentation. A: Gastroscopy revealed a large exophytic and lobular tumor occupying the upper part of the stomach; B: Computed tomography demonstrated a large tumor in the gastric wall and enlarged lymph nodes around the stomach (arrow).

Figure 2

Histopathology. A: Surgical resection revealed a large tumor (75 mm × 75 mm) with central ulceration (Borrmann type III) occupying the anterior wall of the upper body of the stomach; Hematoxylin and eosin staining revealed B: Biphasic structure consisting of tubular adenocarcinoma and spindle cell sarcoma (20 ×); C: Epithelial components showing that the parenchyma structure of the common gastric adenocarcinoma was surrounded with sarcomatous stroma (200 ×); D: Sarcomatous cells proliferating diffusely in a stream pattern (200 ×); E: Two transitional areas of carcinoma and sarcoma components (20 ×).

Figure 3

Immunohistochemistry. Immunoreactivity for A: C-kit (CD117); B: CD34; C: Cytokeratin (AE1/AE3); D: Vimentin; E: Smooth muscle actin; and F: Desmin (200 ×).

Figure 4

Computed tomography findings. A: Nine months after gastrectomy, enlarged heptohilar lymph nodes were detected; B: Heptohilar lymph nodes were decreased in size after 50 Gy radiotherapy; C: Seventeen months after gastrectomy, enlarged mediastinal lymph nodes were detected; D: Mediastinal lymph nodes were decreased in size after 50 Gy radiotherapy.