[Nodulocystic eruption induced by sorafenib]

Introduction: Sorafenib is a multikinase inhibitor used in the treatment of hepatocellular carcinoma, advanced renal cell carcinoma, and differentiated thyroid carcinoma. Cutaneous adverse events are numerous and occur frequently.

Patients and methods: We present two cases of nodulocystic lesions associated with comedones in patients treated with sorafenib for hepatocellular carcinoma. In the first patient, a 64-year-old man, lesions appeared on the trunk one year after beginning sorafenib. Histopathological examination revealed a non-granulomatous, perivascular and perisudoral polymorphic cellular infiltrate associated with comedones and microcysts. These lesions progressed via inflammatory episodes interrupted by long periods of spontaneous remission without any specific treatment. In the second patient, a 53-year-old woman, a rash appeared on the buttocks three months after starting sorafenib and then spread to the lumbar region and thighs. Histopathological examination was consistent with granulomatous acne lesions. The initial treatment (oral tetracycline and zinc) given for 3 months proved ineffective. Patient follow-up over 3 years showed gradual regression without the appearance of any further lesions.

Discussion: In the literature, several reports discuss acneiform rashes in patients treated with targeted therapy. In most cases, these lesions were papulopustular without retentional lesions. There are few reports of nodulocystic eruptions associated with comedones following sorafenib therapy. The mechanisms of emergence of these lesions seem to involve inhibition of the RAF pathway, C-KIT, and the PDGF signaling pathway.