Table 1 Pembrolizumab induces systemic myositis presenting as ocular myositis
| Â | Our case 1 | Our case 2 | Case1 [4] | Case2 [5] |
|---|---|---|---|---|
Age | 78 | 72 | 78 | 86 |
Sex | M | F | M | F |
Carcinoma | pelvis and ureter cancer | lung cancer | metastatic melanoma | metastatic melanoma |
Myositis symptom onset | 7 days after second injection | 2 weeks after second injection | 2 weeks after second injection | 4 days after second injection |
Initial symptom | ptosis | back pain, right-sided ptosis and weakness of neck | bulbar weakness | fatigue, left ptosis and ophthalmoplegia |
CK (IU/L) at the 1st visit | 6416 | 1603 | 1284 | 1499 |
EMG finding | myogenic change | myogenic change | myogenic change | myogenic change |
Serum antibody | PM-Scl 75, SRP | negative | negative | negative |
Anti-AChR antibody | negative | negative | negative | negative |
MG overlap | – | – | – | – |
Pathology | – | necrotizing myositis | necrotizing myositis | necrotizing myositis |
Initial treatment | IVMP | IVMP | PSL 1 mg/kg/day | IVMP |
Second treatment | PLEX | Oral PSL | PLEX | PLEX |
Outcome | dead due to cancer | complete clinical recovery | dead due to respiratory weakness | complete clinical recovery |