Table II.
Histological, immunohistochemical, molecular and electron microscopy features of the reviewed cohort.
| Reference | Histology | p40 | TTF-1 | Molecular alterations | PDL-1 | Electron microscopy |
|---|---|---|---|---|---|---|
| Pelosi, 2015 5 | HG, focal squamous differentiation | + (clone BC28) | + (clone 8G7G3/1) | KRAS K117N, TP53 V272G, FGFR1 amplification | NA | Extracellular lumen formation with microvilli-like protrusion, mucous granules and perinuclear tonofilaments |
| Hayashi, 2018 8 | Solid, focal glandular-like | + (clone BC28) | + (clone 8G7G3/1) | ATK phosphorylation, PTEN H123D, TP53 V272L | NA | NA |
| Spinelli, 2019 9 | Solid | + (polyclonal) | + (clone SPT24) | WT | 70% | NA |
| Pelosi, 2021 15 | HG, resembling squamous differentiation | + (clone BC28) | + (clone 8G7G3/1) | EGFR E746_A750del, TP53 E224D, RAD51B P365R1, CCND3 S259A | Negative | Intracellular luminal bordered by microvilli and fascicles of keratin fibers |
| HG, resembling squamous differentiation | + (clone BC28) | + (clone 8G7G3/1) | NF1 R17691 | 2% | Intracytoplasmatic lumina and fascicles of keratin fibers | |
| Li Hui, 2021 10 | HG, hints of squamous differentiation | + (clone ERB) | + (clone 8G7G3/1) | EGFR L747_S752del, TP53 C135R | NA | NA |
| Chen Bing,2022 11 | HG | + (NA) | + (NA) | NA | NA | NA |
| Yang, 2022 7 | HG, resembling squamous differentiation | + (clone ERB) | + (clone 8G7G3/1) | STK11 A205T, NF1 R1132C, ARID1A Q1334del, BRCA2 D104N, FGFR1 D125del, MSH2 V3M, RET N975I, TSC1 H120D | NA | Microvillous and extended cytoplasm, with intracellular mucus granules and perinuclear tension filaments |
| Cai, 2022 12 | HG | + (NA) | + (NA) | EML4::ALK, PIK3CA S553T | NA | NA |
| Savari, 2022 13 | HG, resembling SCC with focal keratinization | + (clone SP1/Mo) | + (clone 8G7G3/1) | DEK::AFF2, PATCH1 H1316Y, FGFR3 K4031, BLM T1015I, SHH R244S, OLIG2 A227_A223del, WNK1 I7261 | Negative | NA |
| Savari, 2023 14 | HG, resembling NK-SCC | + (clone BC28) | + (clone 8G7G3/1) | TP53 and CDKN2A missense mutation, FGFR1 amplification | NA | NA |
| HG resembling NK-SCC | + (clone BC28) | + (clone 8G7G3/1) | TP53 missense mutation, KRAS G12C, FGFR1 and MYC amplification | NA | NA | |
| HG, resembling SCC with focal keratinization | + (clone BC28) | + (clone 8G7G3/1) | TP53 splice site mutation, FGFR1, MYC, NKX2-1 and AKT1 amplification | NA | NA | |
| HG, resembling SCC with focal keratinization | + (clone BC28) | + (clone 8G7G3/1) | NA | NA | NA | |
| HG, resembling NK-SCC | + (clone BC28) | + (clone 8G7G3/1) | NA | NA | NA | |
| HG, resembling NK-SCC | + (clone BC28) | + (clone 8G7G3/1) | TP53 missense mutation, FGFR1, MYC, NKX2-1 and AKT1 amplification | NA | NA | |
| HG, resembling NK-SCC | + (clone BC28) | + (clone 8G7G3/1) | NA | NA | NA | |
| HG, resembling NK-SCC | + (clone BC28) | + (clone 8G7G3/1) | TP53 splice site mutation, CDKN2A missense mutation, KRAS G12C | NA | NA | |
| HG, resembling NK-SCC | + (clone BC28) | + (clone 8G7G3/1) | NA | NA | NA | |
| HG, resembling NK-SCC | + (clone BC28) | + (clone 8G7G3/1) | NA | NA | NA | |
| HG, resembling NK-SCC | + (clone BC28) | + (clone 8G7G3/1) | NA | NA | NA | |
| HG, resembling NK-SCC | + (clone BC28) | + (clone 8G7G3/1) | TP53 missense mutation | NA | NA | |
| HG, resembling NK-SCC | + (clone BC28) | + (clone 8G7G3/1) | TP53 and CDKN2A truncating mutation, FGFR1 amplification | NA | NA | |
| HG, resembling NK-SCC | + (clone BC28) | + (clone 8G7G3/1) | EGFR N771_H773dup | NA | NA | |
| Present case | HG, resembling squamous differentiation | + (clone DAK-p40) | + (clone 8G7G3/1) | KRAS G12D, MET 14 exon skipping | 40% | NA |
| 1. Variant of Unknown Significance (VUS) | ||||||
| HG high grade, NA not available, NK-SCC non-keatinizing squamous cell carcinoma, SCC squamous cell carcinoma, VUS variant of unknown significance, WT wild type | ||||||