Table 2.
Pathologic features of Adamantinoma-like Ewing Sarcoma cases (n = 7)
| Features | Case 1 | Case 2 | Case 3 | Case 4 | Case 5 | Case 6 | Case 7 |
|---|---|---|---|---|---|---|---|
| Site | Thyroid | Parotid | Parotid | Nasal cavity | Maxilla | Maxilla | Ethmoid/maxilla |
| Initial diagnosis | Poorly differentiated thyroid carcinoma | Sialoblastoma | Basal cell adenocarcinoma | Basaloid SCC | Basaloid SCC | Round cell tumor/solid pseudopapillary tumor | ALES |
| Tumor size (cms) | 3.7 | 3.3 | 2.2 | 5 | 5.5 | 3.6* | 4.3 |
| Cell morphology | Round | Round | Basaloid | Round | Basaloid | Round | Round |
| Cellular appearance | Monotonous | Monotonous | Monotonous | Monotonous | Monotonous | Monotonous | Monotonous |
| Architecture | Nested | Sheets and nests | Nested-lobular | Nested-lobular, focally trabecular | Nested focally; sheets with fibrous bands | Nested | Nested |
| Rosettes | Focal | Absent | Absent | Absent | Focal | Absent | Absent |
| Palisading# | Focal | Focal | Focal | Present | Present | Absent | Absent |
| Squamous | Absent | Absent | Present; abrupt | Present; abrupt | Absent | Absent | Absent |
| Keratinization | Absent | Absent | Present | Absent | Absent | Absent | Absent |
| Calcification | Present | Absent | Present | Absent | Absent | Absent | Absent |
| Follicle-like spaces | Present | Present | Absent | Present | Absent | Absent | Absent |
| Stroma | Hyalinised | Minimal; thin fibrovascular septae | Fibrotic | Hyalinized | Fibrous bands; focally myxoid | Loose edematous | Hyalinized |
| Colonization | Present | Present | Absent | Absent | Absent | Absent | Absent |
| Mitotic rate/2mm2 | 4 | 5 | 15 | 12 | 7 | 12 | 6 |
| Necrosis | Present; min | Absent | Present | Absent | Absent | Present | Absent |
| Lymphovascular invasion | Absent | Absent | Absent | Absent | Absent | Absent | Absent |
| Perineural invasion | Absent | Absent | Present | Absent | Absent | Absent | Absent |
| R status | R0 | R0 | R1 | R0 | R1 | NA | R0 |
| Underlying bone | NA | NA | NA | Cartilage involved | Involved | NA | Involved |
| Lymph nodes metastasis | Clinically node negative | Negative (0/3) | Negative (0/1) | Negative | Negative (0/29) | Not done | Clinically node negative |
SCC squamous cell carcinoma, ALES Adamantinoma-like Ewing sarcoma, min minimal, R status resection margins status, R0 negative margins, R1 microscopically positive margins, NA not available
*Tumor size on imaging
# focal- < 50% of the tumor