PMC10235811_01
(A) Preoperative radiology image shows a large raised mass at the fundus-cardia (red arrow). (B) Gastric endoscopy shows a large raised mass at the fundus-cardia. (C) Gross photograph of the gastric specimen. The tumor section shows gray-white, slightly hard and relatively clear borders.
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A large mass was seen at the stomach fundus and cardia, with a central depression and erosion ( Figures 1A, B ). Gross examination showed a gray-white raised tumor with a size of approximately 10 cmx6.5 cmx4 cm at the stomach fundus and cardia ( Figure 1C ).
(A) In low power, the tumor border is relatively clear and shows expansile infiltration (HE x20). (B) The tumor has two components: adenocarcinoma area and chondromyxoid matrix area. The chondromyxoid matrix exhibits multinodular growth with direct transition of adenocarcinoma components (HE x20). (C) Tumor cells in the carcinomatous area exhibit solid and cribriform morphology (HE x100). (D) Tumor cells show rich eosinophilic cytoplasm, obvious eosinophilic nucleoli and pathological mitosis (HE x200). (E) In the chondromyxoid area, tumor cells are distributed in the form of beams, cords, and single cells within it (HE x100). (F) Tumor cells are eosinophilic, with obvious nuclear atypia, prominent nucleoli, and easy-to-see pathological mitoses (HE x200). (G) The chondromyxoid area is multinodular, with abundant tumor cells around the nodules and sparse tumor cells in the middle (HE x20). (H) Hemorrhage and necrosis are seen in the larger nodules (HE x20).
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On microscopic examination, the tumor showed expansile infiltration with relatively well-circumscribed in low power ( Figure 2A ). Two distinct types of areas were seen within the tumor, including poorly differentiated adenocarcinoma area and area rich in chondromyxoid matrix, and the carcinoma transitions directly to chondromyxoid matrix (without spindle cell sarcomatoid component and osteoclast giant cell differentiation) ( Figure 2B ). The tumor cells in the adenocarcinoma area were arranged in a solid and cribriform pattern, with eosinophilic cytoplasm and large nuclei ( Figure 2C ). Eosinophilic nucleoli are obvious in high power, and pathological mitoses were easy to see ( Figure 2D ). The chondromyxoid matrix was widely distributed in a multinodular pattern, interspersed with poorly differentiated adenocarcinoma and directly migrating to it ( Figure 2B ). Tumor cells were trabecular, cord-like and single cells distributed in the chondromyxoid matrix ( Figure 2E ), with large nuclei, prominent eosinophilic nucleoli and obvious pathological mitoses ( Figure 2F ). The periphery of the nodules were more cellular with gradually diminishing cellularity toward the central area ( Figure 2G ). Hemorrhage and necrosis were present in the center of larger nodules ( Figure 2H ).
HE and Immunohistochemical. (A) The same site of HE section for immunohistochemical tissue sections (HE x200). Tumor cells express CK7 (B), EMA (C) MUC5AC (D) and S-100 (E) (IHC x200). (F) Special histochemical staining of AB-PAS shows the abundant chondromyxoid matrix (Special stain x100).
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AB-PAS staining showed an abundant extracellular chondromyxoid matrix ( Figure 3 ).