Perforating Folliculitis in a Patient Treated With Nilotinib: A Further Evidence of C-kit Involvement

Keratosis Pilaris-like Eruption during Treatment of Chronic Myeloid Leukemia with Tyrosine Kinase Inhibitors: Literature Review and Report of a Case Related to Imatinib

The advent of tyrosine kinase inhibitors (TKIs) blocking BCR-ABL activity has revolutionized the therapeutic management of patients with chronic myeloid leukemia (CML). Adverse cutaneous reactions (ACRs) are common nonhematologic adverse events associated with the use of BCR-ABL TKIs. A characteristic pattern of eruption resembling keratosis pilaris (KP) has been described in patients treated with these drugs, especially nilotinib and dasatinib. The pathogenesis of this ACR is still unknown. This type of reaction appears to be uncommon with imatinib. Here, we report the case of an elderly patient with an asymptomatic KP-like eruption, which appeared one month after starting treatment with imatinib for CML. The case presentation is accompanied by a review of similar reactions in patients with CML treated with BCR-ABL inhibitors, attempting to make an excursus on the molecular targets of such drugs and possible mechanisms underlying this ACR.

Cutaneous side effects in a cohort of patients with chronic myeloid leukemia treated with tyrosine kinase inhibitors: General description and further characterization, correlation with photoexposition and study of hypopigmentation as treatment's prognostic factor

Cutaneous adverse effects (AE) related to tyrosine-kinase inhibitor (TKI) drugs have been mainly described as case reports. We have characterized their appearance and correlation with patient's photoexposition habits and, further, with treatment response, in 61 patients with chronic myelogenous leukemia (CML) treated with TKI drugs. We have found hypopigmentation in 49.2% of the cases and a statistically significant association with interferon (IFN) intake. Eyelid edema's frequency was 45.4%. Mean photo-exposure was 1.95 h/day and only 8.3% of the patients used sunscreen daily. 44.3% of the patients reported a lighter skin color with the treatment and a statistically significant relationship with conjunctival hemorrhage was also found. Concordance between patients and dermatologist was moderate (kappa index 0.41). We found xerosis (21.3%), eczematous eruptions (21.3%), melasma (4.9%) and other isolated skin problems (ie, granulomatous panniculitis) in up to 16.4% of cases. Appearance of hypopigmented macules is associated to vascular conjunctival fragility and these patients need a slightly longer time to reach a complete molecular response, but without additional changes in survival or relapse frequency. We have stablished a specific dermatologic diagnosis in all the cases and we have not found the previously published as maculopapular rashes. Hypopigmentation, the more frequent AE, was not perceived as a relevant side effect. Photosensitivity, in our cases, was not reported, although imatinib-treated patients avoided sun-exposure. In addition, we identified some nonpreviously described dermatologic conditions in patients taking TKI drugs, like granulomatous panniculitis tufted folliculitis or oral spindle cell lipoma.

[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.

Nilotinib-induced Perforating Folliculitis: Two Cases

Cutaneous adverse effects of chemotherapy are widely known but underreported. A significant advancement is made in the field of oncology with the advent of new classes of drug being added to the existing classes at a fast pace. Most of these cutaneous adverse effects are self-limiting and subsides on suspending the drug either temporarily or permanently. Some of these effects are merely overlooked by the patients and the treating physician hence goes un-noticed. Nilotinib is a newer second-generation tyrosine-kinase inhibitor approved for the management of chronic myeloid leukemia. This drug is rapidly establishing itself as afirst-line therapy for chronic myeloid leukemia. Like other chemotherapeutic agents, a wide array of cutaneous adverse effects is noted with this drug. We report two cases of perforating folliculitis induced by nilotinib.

Cutaneous adverse effects of targeted therapies: Part I: Inhibitors of the cellular membrane

There has been a rapid emergence of numerous targeted agents in the oncology community in the last decade. This exciting paradigm shift in drug development lends promise for the future of individualized medicine. Given the pace of development and clinical deployment of targeted agents with novel mechanisms of action, dermatology providers may not be familiar with the full spectrum of associated skin-related toxicities. Cutaneous adverse effects are among the most frequently observed toxicities with many targeted agents, and their intensity can be dose-limiting or lead to therapy discontinuation. In light of the often life-saving nature of emerging oncotherapeutics, it is critical that dermatologists both understand the mechanisms and recognize clinical signs and symptoms of such toxicities in order to provide effective clinical management. Part I of this continuing medical education article will review in detail the potential skin-related adverse sequelae, the frequency of occurrence, and the implications associated with on- and off-target cutaneous toxicities of inhibitors acting at the cell membrane level, chiefly inhibitors of epidermal growth factor receptor, KIT, and BCR-ABL, angiogenesis, and multikinase inhibitors.

Hypopigmented macules secondary to imatinib for the treatment of chronic myeloid leukemia: a histopathologic and immunohistochemical study

BACKGROUND

A few series addressing the cutaneous side effects related to imatinib in the skin have been published, but only one described scarce histopathologic information in seven patients.

OBJECTIVE

To characterize these lesions and compare the number of melanocytes between hypopigmented lesions and normal appearing skin.

METHODS

We retrieved clinical data of the patients and performed 24 skin biopsies (13 from hypopigmented skin and 11 from normal-appearing skin) within a cohort of 41 patients with chronic myeloid leukemia treated with imatinib. We classified the biopsies into three patterns.

RESULTS

About 45% of patients presented with periocular hypopigmentation. Perifollicular fibrosis was observed in hypopigmented skin biopsies (76.9%) and in normal-appearing skin (45.5%). Epidermal melanin, as determined with Masson-Fontana staining, and melanocyte number, as evaluated with MiTF, Melan A and c-kit immunostains, were lower in hypopigmented skin.

CONCLUSIONS

Histopathologic study of hypopigmented macules demonstrates the presence of melanin with a statistically significant decrease in the number of melanocytes. Therefore, these findings differ from vitiligo, as melanocytes are present. Three histopathological patterns may be found, namely (a) perifollicular fibrosis, (b) lichen planopilaris-like and (c) apparently normal skin. One of the most striking histopathologic finding consisted of the presence of perifollicular fibrosis in both hypopigmented lesions and apparently normal skin.