Table 3.
Malignancies with Positive or equivocal (n=12) Internal (in-house) Pan-TRK IHC expression and NTRK NGS results
| Tumor location | Tumor diagnosis | NTRK NGS |
Pan-TRK IHC Reference lab |
Pan-TRK IHC In-house |
|---|---|---|---|---|
| Parotid gland | Secretory carcinoma | ETV6-NTRK3 | Positive | Positive (nuclear, 2+, 5%) |
| Parotid gland | Secretory carcinoma | ETV6-NTRK3 | Positive | Positive (cytoplasmic, 1+, 20%) |
| Parotid gland | Secretory carcinoma | ETV6-NTRK3 | Positive | Positive (cytoplasmic 1+, 100%; rare, focal nuclear staining, 2+, peripherally) |
| Parotid gland | Secretory carcinoma | ETV6-NTRK3 | Positive | Positive (cytoplasmic, peripherally, 1+, 5%) |
| Parotid gland | Secretory carcinoma | ETV6-NTRK3 | Positive | Positive (nuclear, peripherally, 2+, 15%) |
| Submaxillary gland | Secretory carcinoma | ETV6-NTRK3 | Positive | Positive (cytoplasmic 1+, 100%; scattered nuclear, 2+) |
| Lung | Metastatic MEC | ETV6-NTRK3 | Positive | Positive (cytoplasmic and nuclear staining, 1-2+, 100%) |
| Breast | Secretory carcinoma | ETV6-NTRK3 | Positive | Positive (nuclear and cytoplasmic, 2-3+, 70%) |
| Soft tissue-popliteal area | MPNST | TPM4-NTRK3 | Positive | Positive (cytoplasmic, 3+, 80%) |
| Soft palate | Polymorphous adenocarcinoma | No fusion detected | Positive | Positive (cytoplasmic, 2+, 90%) |
| Pleural fluid | Metastatic carcinoma, unknown origin | N/A | Positive, Focal | Equivocal (punctate, 1%) |
| Ovary | HGSC | NTRK1 truncation- intron 2 | Positive, Focal | Equivocal (punctate, 5%) |
Abbreviations: MPNST malignant peripheral nerve sheath tumor, HGSC high-grade serous carcinoma, MEC mucoepidermoid carcinoma, N/A not tested