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case_images: Morphological characteristics of the lipoblastic nerve sheath tumor. (A) The vestigial peripheral lymph node tissue underwent compression from a multinodular tumor (HEx20). (B) Spindle tumor cells were aligned in intersecting fascicles with nuclear palisades forming Verocay bodies (HEx100). (C) The distribution of mature adipocytes and lipoblast-like cells, interspersed with sporadic atypical cells in a disordered pattern (HEx100). (D) Certain cells exhibited marked atypia with aberrant nuclei and striking nucleoli, notwithstanding the absence of mitotic activity or necrosis (HEx400).
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case_images: Microscopic examination revealed the presence of residual peripheral lymph node tissue, which was compressed by a multinodular neoplasm ( Figure 1A ). The neoplasm was composed of moderately cellular spindle cells, arranged in crossing bundles with focal nuclear palisades and embedded within a variably collagenous matrix, forming verocay bodies ( Figure 1B ). Upon further examination, mature adipocytes as well as lipoblast-like cells displaying a signet-ring cell appearance were scattered or densely distributed in certain areas ( Figure 1C ). Some of tumor cells showed obvious atypia with vesicular cytoplasm and bizarre nucleus with prominent nucleoli ( Figure 1D ), but no evidence of mitotic activity or necrosis was observed. The MDM2/CEP12 signal ratio was determined to be 1.04, and the CDK4/CEP12 signal ratio was 1.05, as illustrated in  Supplementary Figure 1 .
case_images: Immunohistochemical phenotype of the lipoblastic nerve sheath tumor. The immunohistochemical analysis demonstrated a diffuse and strong positive staining for S-100 (A), SOX10 (B), and CD56 (C) in the spindle cells as well as in the signet-ring lipoblast-like cells and the mature adipocytes. Additionally, Melan-A (D) exhibited diffuse positivity. Scattered positive staining for CDK4 (E) was observed, while MDM2 (F) showed negative staining. Furthermore, the histone 3 trimethyl K27 (H3K27me3) stain revealed nuclear positivity in the tumor cells (G). The proliferative index, as indicated by the Ki-67 staining, was less than 5% (H).
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case_images: The immunohistochemical analysis conducted on the tumor cells revealed a diffuse expression of S-100 ( Figure 2A ), SOX10 ( Figure 2B ), CD56 ( Figure 2C ), NSE, MelanA ( Figure 2D ), INI1, and vimentin in the spindle cells as well as in the signet-ring lipoblast-like cells. Figure 2E ) was positive in the scattered tumor cell nuclear, while MDM2 was totally negative ( Figure 2F ). Furthermore, a subsequent investigation utilizing a histone 3 trimethyl K27 (H3K27me3) stain showed diffuse nuclear positivity in the tumor cells ( Figure 2G ). The proliferative index, as determined by Ki-67 was less than 5% ( Figure 2H ).
case_images: KEGG analysis of the 10 genes identified in the lipoblastic nerve sheath tumor occurring in an inguinal lymph node.
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case_images: Interestingly, KEGG pathway analysis of these 10 genes demonstrated significant enrichment in two main pathways: EGFR tyrosine kinase inhibitor resistance and MAPK signaling ( Figure 3 ).