An unusual terminal hair growth on the nose tip associated with gefitinib therapy

Abstract

Conflicts of interest: none declared. Sir, The epidermal growth factor receptor (EGFR) pathway, a key driver in regulating normal epithelial cell growth and differentiation, also plays a role in promoting proliferation of malignant epithelial cells1 by increasing proliferation, adhesion and invasive capacity, and also by blocking apoptosis.1–4 For this reason, EGFR expression is associated with metastasis, late‐stage disease, resistance to therapy and poor prognosis. Therapies targeting EGFR are now under development, such as antibodies to EGFR or EGFR‐specific tyrosine kinase inhibitors. Gefitinib, also known as ZD 1839 or Iressa®, is a low‐molecular‐weight compound that inhibits the activation of EGFR tyrosine kinase through competitive binding of the receptor.1–4 A 65‐year‐old woman presented with a 2‐month history of asymptomatic, brown to black hairs on the nose tip that had been gradually thickening and lengthening (Fig. 1). Six months before, she had been diagnosed with metastatic lung adenocarcinoma and had undergone treatment with radiotherapy (whole brain and femur, 3000 cGy × 2 cycles) and chemotherapy (docetaxel 100 mg daily every 3 weeks for 2 months). Two months before, she began treatment with gefitinib 250 mg daily. One week after starting treatment, she noticed tiny brown to black spots on her nose tip. Ever since, hairs have been growing at these sites. When she presented to our department, the hairs were 1–3 mm in length, localized to the nose tip. There were no vellus hairs, which normally there should be. There was no abnormality of hair density or length at other body sites. She denied a personal history of other cutaneous problems, trauma or administration of any drugs such as might induce hair growth. Skin biopsy revealed multiple hair follicles in anagen phase that were located in the superficial dermis (Fig. 2). The hair shaft was 0·054 mm in diameter and was myelinated, indicative of terminal hair. There was also solar elastosis and a mild inflammatory infiltrate in the papillary dermis. On the basis of these findings, the patient was diagnosed with terminal hair growth associated with gefitinib and was recommended to discontinue gefitinib. However, as the patient's lung adenocarcinoma had had a poor response to radiochemotherapy, gefitinib could not be discontinued and the hairs have continued to grow.