Pancreatic perivascular epithelioid cell tumor: A case report with clinicopathological features and a literature review

Figure 1 Abdomen computed tomography-scan. A: CT delayed phase: a relatively low density of nodules (arrow) of approximately 1 cm × 1.4 cm in the uncus of the pancreas; B: Round abnormal signal (arrow) of 1.7 cm × 1.4 cm was found in the head and uncus of the pancreas, T1WI showed low signal, clearly contrasting with normal pancreatic tissue surrounding a relatively high signal.

Figure 2 Cytology results. A: Cells were irregular lumps distributed with medium nuclei sizes, arranged in a disorderly manner, and with crowded overlap; B: Tumor cell with abundant cytoplasm and unclear boundary. Messily arranged spindle cell nuclei can be seen in some cell clumps. Scattered single cells were found in the background.

Figure 3 Biopsy specimen. Hematoxylin-eosin staining shows the epithelial tumor cells with bright or slightly eosinophilic granules with nested distribution.

Figure 4 Gross examination. Tumor 2 cm × 2 cm in size in pancreatic head with clear boundaries. Cross-section of gray and solid soft texture. Metastatic lesions were not found.

Figure 5 Microscopic examination. A: Microscopy showing clear boundaries between the tumor and adjacent pancreatic tissue; B: Mounts of vessel were in mesenchyma, with hyaline degeneration present; C: Epithelioid tumor cell; D: Spindle-shaped tumor cell with bright or slightly eosinophilic granule. A, B, C and D: Hematoxylin-eosin staining.

Figure 6 Immunohistochemistry. A: Tumor cells expressed HMB-45; B: Tumor cells are immunophenotypically positive for the melanocytic marker melan-A; C: Tumor cells are immunophenotypically positive for the smooth muscle marker SMA. Original magnification × 200. A, B and C: Immunostaining.