Chronic myelogenous leukemia (CML) is characterized by a reciprocal translocation between the long arms of chromosomes 9 and 22 leading to the formation of a constitutively active tyrosine kinase. Tyrosine kinase inhibitors (TKIs) are the treatment of choice for patients diagnosed with CML and have many associated side effects including the rarely-reported eruption of squamous cell carcinomas (SCCs). Herein, we report a patient with CML who presented with sudden onset of multiple scaly lesions on his legs and trunk after beginning treatment with nilotinib, a novel TKI. Six biopsies were performed at his initial presentation and four of these lesions were confirmed to be keratoacanthoma-type SCCs. One month later, the patient reported the development of multiple new similar lesions on his legs, arms, and face. Four more biopsies were performed revealing keratoacanthoma-type and well-differentiated SCCs. Certain tyrosine kinase inhibitors such as sorafenib and quizartinib have been reported to cause eruptive keratoacanthoma (KA)-type SCCs as seen in our patient. However, there is only one other report in the literature of nilotinib promoting the development of SCCs or KAs. Physicians should be aware of this potential adverse effect and patients taking nilotinib should be closely monitored by a dermatologist.

A 74-year-old woman who presented initially with trigeminal neuralgia of the left forehead and scalp was later found to have a poorly differentiated squamous cell carcinoma (SCC) with large-nerve perineural and intraneural invasion of the left supraorbital nerve. Negative histopathologic margins were achieved in three stages of permanent fixed tissue en face processing and the final defect was repaired with a large rotation flap. Approximately one month after repair, the patient presented with new-onset diplopia and was found to have a complete left cranial nerve VI palsy suspicious for continued disease spread. MRI confirmed perineural spread along the ophthalmic branch of the trigeminal nerve through the superior orbital fissure into the cavernous sinus. She was subsequently treated with radiation therapy (66Gy in 33 fractions). The involvement of two distinct cranial nerves by perineural invasion is uncommon and has mostly been described involving branches of the trigeminal and facial nerves. This case highlights the rare presentation of perineural invasion involving both the trigeminal nerve and the abducens nerve. Anatomically, this clinical presentation can be explained by the retrograde perineural spread along the ophthalmic branch of the trigeminal nerve through the supraorbital fossa into the cavernous sinus where these two nerves are in close proximity.