Department of Pathology, Tachikawa General Hospital, Nagaoka, Niigata, Japan.
Histopathology Core Facility, Niigata University Faculty of Medicine, Niigata City, Niigata, Japan.
Am J Case Rep. 2022 Jan 8;23:e934586. doi: 10.12659/AJCR.934586.
BACKGROUND Gastric carcinoma (GC) remains one of the most common and deadly neoplasms in the world. Liposarcoma (LPS) is the most common sarcoma of adults. However, synchronous or metachronous occurrence of GC with LPS seems to be very rare. Tumor staging and differential diagnosis with these cases are extremely difficult. CASE REPORT The patient was a man in his 70s, who reported anorexia and weight loss of 4 kg over 2 months. Gastroscopy demonstrated a large tumor of Borrmann type 3, of which histology was moderately to poorly differentiated adenocarcinoma. The clinical stage was initially defined as IVb due to a 11×6 cm retroperitoneal (RP) tumor. Despite chemotherapy for GC, the RP tumor rapidly enlarged. Endoscopic ultrasound-guided fine-needle aspiration biopsy showed that it was an undifferentiated sarcoma. He died of hepatorenal failure secondary to severe jaundice. The autopsy revealed a synchronous occurrence of GC and RP sarcoma. GC had no areas admixed with sarcoma. Histology of RP sarcoma showed that it mainly consisted of undifferentiated sarcoma and focally of well-differentiated LPS characterized by well-differentiated adipocytes admixed with scattered atypical stromal cells. The tumor cells in both areas were positive for MDM2 and CDK4 by immunohistochemistry. The diagnosis of the RP sarcoma was revised to dedifferentiated LPS. CONCLUSIONS There were no previous case reports of synchronous occurrence of GC with LPS in the English and Japanese literature. GC and LPS pose challenging problems in their diagnoses, staging, and treatments when they occur synchronously or metachronously.
胃癌（GC）仍然是世界上最常见和最致命的肿瘤之一。脂肪肉瘤（LPS）是成人最常见的肉瘤。然而，GC 与 LPS 同时或异时发生似乎非常罕见。这些病例的肿瘤分期和鉴别诊断极其困难。
患者为 70 多岁男性，自述 2 个月来食欲不振和体重减轻 4 公斤。胃镜检查显示为 Borrmann 3 型大肿瘤，组织学为中至低分化腺癌。临床分期最初定义为 IVb 期，因为腹膜后（RP）有一个 11×6 cm 的肿瘤。尽管对 GC 进行了化疗，但 RP 肿瘤迅速增大。内镜超声引导下细针抽吸活检显示为未分化肉瘤。他因严重黄疸继发肝肾衰竭而死亡。尸检显示 GC 和 RP 肉瘤同时发生。GC 没有与肉瘤混合的区域。RP 肉瘤的组织学主要由未分化肉瘤组成，局部由分化良好的 LPS 组成，特征为分化良好的脂肪细胞混杂有散在的非典型基质细胞。免疫组织化学显示两个区域的肿瘤细胞均为 MDM2 和 CDK4 阳性。RP 肉瘤的诊断修订为去分化 LPS。
在英语和日语文献中，没有关于 GC 与 LPS 同时发生的先前病例报告。GC 和 LPS 同时或异时发生时，在诊断、分期和治疗方面带来了具有挑战性的问题。
