J Gastric Cancer.  2014 Sep;14(3):207-210. 10.5230/jgc.2014.14.3.207.

Gastric Adenocarcinoma with Thymic Metastasis after Curative Resection: A Case Report

• Matsunaga
• Saito H
• Miyatani K
• Takaya S
• Fukumoto Y
• Osaki T
• Ikeguchi M

• KMID: 2372533
• DOI: http://doi.org/10.5230/jgc.2014.14.3.207

Abstract

The peritoneum is the most frequent site of recurrence for gastric cancer after gastrectomy, followed by the liver and lymph nodes. In contrast, metastasis to the thymus is rare. Annual surveillance with computed tomography was performed on a 67-year-old man who previously underwent a distal gastrectomy and D2 lymph node dissection for gastric cancer at Tottori University. Five years after the initial operation, an anterior mediastinal tumor was detected by computed tomography. The patient underwent video-assisted thoracic surgery to remove the tumor. Histopathology revealed adenocarcinoma cells similar to those of the gastric cancer resected 5 years previously. Thymic metastasis was considered likely based on the location of the tumor. The recognition that gastric cancer can metastasize to unusual anatomic locations, such as the thymus, can facilitate an accurate, prompt diagnosis and appropriate treatment.

Keyword

Stomach neoplasms; Neoplasm metastasis

MeSH Terms

Adenocarcinoma*
Aged
Diagnosis
Gastrectomy
Humans
Liver
Lymph Node Excision
Lymph Nodes
Neoplasm Metastasis*
Peritoneum
Recurrence
Stomach Neoplasms
Thoracic Surgery, Video-Assisted
Thymus Gland

Figure

• 

  Fig. 1 Gastrofibroscopy showed a type 0-IIa+IIc lesion with a maximum size of 20 mm in the posterior side of the lower third of the stomach.

• 

  Fig. 2 Enhanced computed tomography scan revealed an anterior mediastinal tumor.

• 

  Fig. 3 Positron emission tomography computed tomography showed a focal hypermetabolic lesion with a maximum standardized uptake value of 3.6 in the anterior mediastinum. There was no accumulation of 18F-fluorodeoxyglucose in the liver, lungs, lymph nodes, or peritoneum.

• 

  Fig. 4 The tumor in the anterior mediastinum was removed, including the surrounding fat tissue.

• 

  Fig. 5 Histopathological examination of the anterior mediastinal tumor showed a poorly differentiated adenocarcinoma that was similar to the gastric cancer removed 5 years previously. (A) Histopathological examination of gastric carcinoma (H&E, ×10). (B) Histopathological examination of the anterior mediastinal tumor (H&E, ×10). Furthermore, immunochemistry indicated that tumor cells were positive for cytokeratin 20 and CDX-2 (C, D) but negative for cytokeratin 7 (data not shown) (C: cytokeratin 20, ×10; D: CDX-2, ×10).

Reference

1. Saito H, Tsujitani S, Kondo A, Ikeguchi M, Maeta M, Kaibara N. Expression of vascular endothelial growth factor correlates with hematogenous recurrence in gastric carcinoma. Surgery. 1999; 125:195–201.

2. Japanese Gastric Cancer Association. Japanese classification of gastric carcinoma: 3rd English edition. Gastric Cancer. 2011; 14:101–112.

3. Hayashi S, Hamanaka Y, Sueda T, Yonehara S, Matsuura Y. Thymic metastasis from prostatic carcinoma: report of a case. Surg Today. 1993; 23:632–634.

4. Clark SL Jr. The reticulum of lymph nodes in mice studied with the electron microscope. Am J Anat. 1962; 110:217–257.

5. Phillips CJ. Case report: metastatic malignant testicular teratoma of the thymus. Br J Radiol. 1994; 67:203–204.

6. Nam MS, Chu YC, Choe WS, Kim SJ, Hong SB, Kim YJ, et al. Metastatic follicular thyroid carcinoma to the thymus in a 35-year-old woman. Yonsei Med J. 2002; 43:665–669.

7. Park SB, Kim HH, Shin HJ, Paik MH, Kim DB, Gong G. Thymic metastasis in breast cancer: a case report. Korean J Radiol. 2007; 8:360–363.

8. Middleton G. Involvement of the thymus by metastic neoplasms. Br J Cancer. 1966; 20:41–46.