Distant metastasis in the right inguinal area from gastric cancer: A case report

Abstract

BACKGROUND

Gastric cancer is the fifth most common cancer and the fourth leading cause of death worldwide. Most cases of newly diagnosed gastric cancer involve not only locally advanced tumor growth and regional lymph node metastases but also distant metastases. We report a rare case finding of a mass in the right inguinal area which is derived from gastric cancer.

CASE SUMMARY

A 68-year-old male initially diagnosed with an inguinal hernia presented with a 2 cm mass in the right inguinal area. Gastrointestinal symptoms led to the discovery of a stomach tumor. Biopsy confirmed gastrointestinal adenocarcinoma. The diagnosis was advanced gastric cancer with peritoneal dissemination, and the inguinal mass was due to direct infiltration. Due to gastrointestinal bleeding, the patient underwent palliative gastrectomy and lymph node dissection. Postoperatively, the patient received hyperthermic intraperitoneal chemotherapy and localized radiation therapy.

CONCLUSION

This case indicates that a systematic evaluation should be conducted during the initial consultation to explore the potential connection between unrecognized distant masses and the primary tumor.

Key Words: Gastric cancer; Neoplasm metastasis; Distant metastasis; Case report

Core Tip: This case highlights the importance of thorough evaluation in patients presenting with unusual masses, such as an inguinal mass, to identify potential distant metastases from primary gastric cancer. Early diagnosis and multidisciplinary treatment, including palliative surgery, hyperthermic intraperitoneal chemotherapy, and radiation, can improve patient management in advanced gastric cancer.

INTRODUCTION

Gastric cancer (GC) is the fifth most common cancer and the fourth leading cause of death worldwide[1]. Most cases of newly diagnosed gastric cancer involve not only locally advanced tumor growth and regional lymph node metastases but also distant metastases. The most common distant metastases of gastric cancer include the liver, peritoneum, lung, and bone[2]. Approximately 27% of gastric cancer patients have synchronous peritoneal metastases (PM) at initial diagnosis[3]. Peritoneal implantation metastases commonly occur in the omentum, pelvis, mesentery, diaphragm, and the small intestine and its mesentery, due to the structural and vascular characteristics of these areas that facilitate the deposition and proliferation of cancer cells.

We present a case of a patient who sought medical attention due to the discovery of a mass in the right inguinal area. Further gastroscopy and biopsy confirmed gastric cancer with concurrent gastric retention. During hospitalization, the right inguinal mass underwent a puncture biopsy. Subsequently, the patient experienced upper gastrointestinal bleeding, and conservative medical treatment and endoscopic assessment were ineffective, leading to emergency surgical intervention. Postoperatively, the biopsy of the puncture revealed that the inguinal mass originated from metastatic gastrointestinal adenocarcinoma.

CASE PRESENTATION

Chief complaints

A 68-year-old male patient presented with a solid mass in the right inguinal area and dull pain in the right scrotum, persisting for the past two months.

History of present illness

The patient had previously been diagnosed with an inguinal hernia at a local hospital. During treatment there, he experienced symptoms including nausea, vomiting, and loss of appetite, leading to a weight loss of approximately 15 kg. He was subsequently referred to our hospital for further evaluation and management.

History of past illness

The patient had a free previous medical history.

Personal and family history

The patient had no significant personal or family medical history.

Physical examination

Upon admission, the patient's vital signs were stable. Physical examination revealed a hard, fixed mass measuring approximately 2.5 cm × 2.0 cm × 1.5 cm in the right inguinal region, with ill-defined borders and significant tenderness upon palpation. No signs of skin ulceration or itching were observed.

Laboratory examinations

Elevated serum tumor markers were noted, with carcinoembryonic antigen levels at 18.70 ng/mL and carbohydrate antigen 19-9 levels at 578.5 U/mL.

Imaging examinations

Upper gastrointestinal endoscopy indicated gastric retention and a large ulcerative lesion in the antrum. Computed tomography (CT) imaging showed a thickening of the lesser curvature of the gastric antrum wall. Additionally, a soft tissue shadow was detected in the right inguinal area (Figure 1). Color doppler ultrasound of the right inguinal mass showed a heterogeneous echo pattern measuring approximately 22 mm × 13 mm × 26 mm, with ill-defined borders and irregular shape, and blood flow signals were detected within the mass (Figure 2A). A fine needle aspiration biopsy was performed under the guidance of color Doppler ultrasound (Figure 2B).

Figure 1  A contrast-enhanced computed tomography image of the abdomen showed a soft tissue shadow in the right inguinal area.

Figure 2 Ultrasound imaging and ultrasound-guided biopsy of the right inguinal mass. A: Color doppler ultrasound of the right inguinal mass showed a heterogeneous echo pattern; B: Fine needle aspiration of the right inguinal mass under the guidance of Color doppler ultrasound.

FINAL DIAGNOSIS

Biopsy specimens revealed moderately to poorly differentiated adenocarcinoma (G2-G3). Immunohistochemical analysis showed the mass was CK7-positive, CK20-negative, CDX-positive, Villin-positive, PSA-negative, TTF-1-negative, and HER2 (0), confirming metastasis of digestive tract adenocarcinoma (Figure 3). The patient was finally diagnosed with gastric cancer with right inguinal metastasis. Pathological stage: PT4aN3aM1.

Figure 3 Pathological examination of fine needle aspiration biopsy showed adenocarcinoma. A: Hematoxylin and eosin-stained section; B: Villin positive.

TREATMENT

During hospitalization, the patient's right inguinal mass underwent a puncture biopsy. However, before the biopsy pathology results were available, the patient suddenly developed upper gastrointestinal bleeding. As conservative medical treatment and endoscopic assessment were ineffective, emergency surgical intervention was urgently carried out. The surgery revealed implantation nodules on the peritoneum and PM staged as P1c, located in zones 2, 5, and 6, with a peritoneal cancer index of 3. Additionally, a locally resectable gastric tumor was identified. The patient subsequently underwent palliative total gastrectomy and D2 lymph node dissection. The excised specimen showed a Borrmann type III advanced gastric tumor, measuring 4.7 cm × 4.5 cm × 1.5 cm, located on the lesser curvature of the gastric antrum. The tumor was ulcerated, and bleeding was observed. Pathological examination indicated that there were no residual cancer cells at the proximal and distal margins. Pathological analysis of the primary gastric carcinoma, classified according to the Japanese Classification of Gastric Carcinoma, revealed moderately to poorly differentiated adenocarcinoma. Thirteen of the nineteen resected regional lymph nodes were positive, specifically in the No. 1, 3, 4, 5, 6 (sub-pyloric), 9, and 12 regions. Lymphatic vessel, vascular, and nerve invasion were noted. Postoperatively, the patient received hyperthermic intraperitoneal chemotherapy along with enteral and parenteral nutrition support, and the postoperative course was uneventful. One week post-surgery, the biopsy of the puncture revealed that the inguinal mass originated from metastatic gastrointestinal adenocarcinoma. One month after surgery, the patient continued to receive radiation therapy in the right inguinal area.

OUTCOME AND FOLLOW-UP

After undergoing palliative gastrectomy, the patient experienced moderate improvement in gastrointestinal symptoms. However, after discharge, the patient was lost to follow-up. Through subsequent telephone communication, we learned that he survived for 10 months post-surgery.

DISCUSSION

Gastric cancer mainly metastasizes to the lymph nodes, liver, and peritoneum[2]. PM is a very poor prognostic factor in patients with advanced gastric cancer[4]. To our knowledge, a few cases have reported gastric cancer metastasis to the umbilicus[5], port site[6], and lower chest[7]. Additionally, metastases to the left armpit[8], scalp[9], and face[10] have been reported, which are far from the stomach. In our case, a patient with a solid mass in the right inguinal area presented with dull pain in the right scrotum. It was initially presented to the urology department and first suspected to be an abdominal wall disease, such as an inguinal hernia, based on clinical findings. However, as gastrointestinal symptoms emerged and a gastroscopy was completed, it was discovered that the patient had primary gastric cancer. Although the mass was biopsied, the occurrence of gastrointestinal bleeding necessitated prompt surgical intervention.

The possible origins of the right lump in the inguinal area are hematogenous metastasis, lymphogenous metastasis from inguinal lymph nodes, and direct infiltration from peritoneal dissemination. The inguinal mass visible on ultrasound and CT scan images appears to be located in the inguinal canal. Since this patient had peritoneal dissemination and no other metastatic lesions suspected of hematogenous or lymphogenous metastasis, direct infiltration from peritoneal dissemination was most likely. We infer that due to implantation in the inguinal hernia sac, a mass formed within the inguinal canal over time. The prognosis of advanced gastric cancer is known to be poor, with the median survival of patients with unresectable advanced gastric cancer being 10-18 months[11]. Early diagnosis of unusual metastasis and implementation of standard treatment before the onset of new clinical symptoms or general deterioration can improve the prognosis and quality of life. We experienced a rare case of distant metastasis in the right inguinal area originating from primary gastric cancer. Clinicians should always keep in mind that distant metastasis is a possible diagnosis when a new mass appears or with discomfort, which may be a signal of patients with preexisting internal organ malignancies. Attention should be paid to the systematic review during the consultation to explore possible connections.

CONCLUSION

We report a sporadic case of distant metastasis of gastric cancer to the right inguinal region. For patients with gastrointestinal symptoms, local masses should be given high attention. Patients with distant metastasis often have a poor prognosis. Various imaging techniques and fine-needle aspiration biopsy aid in detecting subcutaneous metastatic lesions, and radiotherapy is a possible treatment option.