A 61-year-old man was admitted to our hospital in May 2022 for three progressively enlarging masses in the left groin area and head, along with redness and swelling of the left thigh for more than half a year. He had a history of a major gastrectomy in 2015 after being diagnosed with gastric carcinoma. The patient was diagnosed with a 2.0x1.5x1.0cm tumor at the angle of stomach, and treated with Billroth II distal gastrectomy accompanied with D2 lymph node dissection. The postoperative histopathology of the primary lesion was mixed invasive adenocarcinoma, of which signet-ring cell carcinoma accounted for 80%, and tubular adenocarcinoma accounted for 20% ( Figure 1 ). The pathological stage was pT1N3M0. So, the patient received two cycles of oxaliplatin and tegafur chemotherapy, which was discontinued due to the inability to tolerate the side effects of chemotherapy. No tumor recurrence was found in the annual gastroscopy and CT-scan for 4 years after the operation; then, no follow-up was performed due to the COVID-19 epidemic.
However, after 6 years, the patient developed a beaded nodular tumor in the left groin area and two fleshy nodules on the scalp, accompanied by redness and swelling from the upper left thigh to the groin area; there was no obvious fever or pain. This patient was diagnosed with "lymphangitis of lower limbs" in several major hospitals and was prescribed anti-inflammatory and detumescence treatment. After repeated treatment, the tumor in the left groin area and scalp gradually increased, and the skin of the left lower extremity was red, swollen, and scleroderma-like. Finally, he came to our hospital for treatment.
A physical examination revealed moderate pitting edema of the left lower extremity, redness and swelling of the thigh with scleroderma-like changes, bead-like nodules of about 5*20cm in the groin area ( Figure 2A ), and two fleshy masses of about 3*3cm in size on the scalp ( Figures 2B, C ). The laboratory examinations showed that the blood routine, procalcitonin, liver, and kidney function were not abnormal, and the tumor markers carbohydrate antigen 72-4 and CA125 were elevated. A skin biopsy was performed on the groin mass, and the pathology showed metastatic poorly differentiated carcinoma, some of which were signet-ring cell carcinoma; immunohistochemical staining showed: PCK(+), CK7(+), CK20(-), CDX2(+), SATB2(-), and HER2(0) ( Figure 3 ). A whole-body PET-CT examination showed multiple humus-like hypodense nodules on the skin surface from the left groin to the thigh, secondary lymphedema, and slightly increased metabolic diffusion ( Figure 4A ). There was also localized thickening of the skin on the top of the left head and back of the neck, and slightly increased metabolism. The above suggested the possibility of malignant tumor metastatic lesions ( Figure 4B ). After the diagnosis was confirmed, the patient was transferred to the oncology department for chemotherapy of Nivolumab combined with SOX. Four times of chemotherapy had been performed, and the efficacy was evaluated as reduced SD. Due to the COVID-2019 epidemic, the patient did not come to our hospital for subsequent chemotherapy treatment as planned.