Unilateral Spermatic Cord Metastasis from Gastric Cancer: A Case Report

Malignant spermatic cord tumor is rare. Spermatic cord metastasis is less common and the prognosis of these patients is poor. Here we report a case of unilateral spermatic cord metastasis from advanced gastric cancer. A 57-year-old male underwent total gastrectomy due to advanced gastric cancer. Three years later, a painless hard palpable mass in the left inguinal area developed and the pathology revealed a spermatic cord metastasis from stomach cancer.


Introduction
Malignant lesions of the spermatic cord, both primary and metastatic are extremely uncommon (1) and reports of radiological findings of spermatic cord metastasis are rare. Here we report ultrasonographic, computed tomography (CT) and magnetic resonance imaging (MRI) findings in a case of unilateral spermatic cord metastasis from gastric cancer.

Case Presentation
A 57-year-old male underwent total gastrectomy for an advanced gastric cancer (Borrmann type 2). The histology revealed poorly differentiated adenocarcinoma, penetration of the serosa and regional lymph node metastasis. The patient was followed for 3 years with no evidence of recurrence on computed tomography (CT) scans, endoscopy and PET-CT scans. Three years later, heterogeneous enhancement and thickening of the left spermatic cord was revealed on a follow-up CT scan ( Figure 1A). On physical examination, a hard palpable mass was found in the left inguinal area. Ultrasonography revealed an irregular marginated, hypoechoic mass with increased vascularity ( Figure 1B) to vascular congestion. On MRI scan, the mass appeared as a diffuse thickening of the left spermatic cord with an irregular margin and high-signal intensity on the T2weighted image, iso-signal intensity on the T1-weighted image and heterogeneous enhancement on the enhanced-T1-weighted image ( Figure 1C and D). The patient underwent left radical orchiectomy. The spermatic cord showed an infiltrative solid mass on gross specimen approximately 4 × 1 cm in size ( Figure 1E). The pathology revealed atypical glandular structures with malignant cells and was diagnosed as metastatic adenocarcinoma of the spermatic cord from gastric cancer ( Figure 1F). The testis and epididymis were histopathologically determined to be free of carcinoma. This patient was followed up with conservative treatment. After 3 months, this patient complained of a palpable mass with pain between the left inguinal area and scrotum. Resection of this mass was performed without a preoperative imaging study. The pathologic result was "metastatic adenocarcinoma probably from the stomach".

Discussion
The spermatic cord is an extremely rare site for distant metastasis from a malignant tumor. In adults, most spermatic cord tumors are malignant and have a sarcomatous origin (1,2). A study of the spermatic cord and epididymis tumors revealed 28.8% were malignant and of those, 8.1% were metastasis (1).
The most common primary origin of a spermatic cord metastasis is the gastrointestinal tract, followed by the pancreas, prostate and the kidneys (3,4). The colon is the most common primary site originating from the gastrointestinal tract (5); however, in Japan the most frequent primary site is the stomach (3), which may be the result of the high incidence of gastric cancer in that country. Hematogeneous or lymphatic spread are the main routes of metastasis to the spermatic cord; other routes include retrograde extension through the vas deferens, either along its lumen or as a direct extension via the wall of the vas deferens and trans-peritoneal seeding through a patent tunica vaginalis (6). It was not possible to determine if hematogeneous or lymphatic spread occurred in our patient. Clinically, most patients with spermatic cord metastasis present with a painless scrotal mass, although a lower inguinal mass and enlargement of the testis can occur. Hydrocele, hernia and testicular tumors are the most common misdiagnoses of metastatic tumors (7).
Our patient also demonstrated a hard palpable mass on the left inguinal area. In a previous case report, spermatic cord metastasis from lung cancer appeared on the ultrasonogram as a hypoechoic mass in the inguinal canal with an extension into the scrotum and as a solid mass with inner necrosis on CT scan (8). In our case, the radiological findings of spermatic cord metastasis were a mass formation along the spermatic cord and hypoechogenicity on the ultrasonogram; heterogeneous en-hancement on the CT scan and hyper-intensity on theT2weighted image; iso-intensity on the T1-weighted image and heterogeneous enhancement on the enhanced T1weighted image. None of the imaging modalities revealed an area of internal necrosis within the mass.
The prognosis for spermatic cord metastasis is poor. In a previous study, the average survival from the time of diagnosis was 9.1 months (4). The use of chemotherapy and radiotherapy for the treatment of tumors with spermatic cord metastasis is controversial (9). The present case report describes ultrasonographic, CT and MRI findings of spermatic cord metastasis seen as a mass or thickening of spermatic cord with an irregular margin.