Scanning electron microscopy of panitumumab-induced eyelash and hair alterations - Pili canaliculi

Abstract Panitumumab is a monoclonal antibody against the epidermal growth factor receptor used in metastatic colorectal cancer; in addition to tumor cells, it acts on epidermal keratinocytes and on the outer root sheath and presents skin toxicity in up to 90% of cases. A scanning electron microscope was used to examine the eyelashes and hairs of a 65-year-old patient with eyelash trichomegaly, curly hair, and paronychia undergoing treatment with panitumumab. Grooving in the hair shafts were identified, which were more evident in the eyelashes. Similar to oral epidermal growth factor inhibitors (erlotinib and gefitinib), panitumumab can cause acquired pili canaliculi.

Scanning Electron Microscopy of Subclinical Gefitinib-Induced Hair Changes.

Oral inhibitors of epidermal growth factor receptor may have a wide range of cutaneous manifestations. Hair manifestations are observed in 10%-20% of the patients. At the ultrastructural level erlotinib-induced hair changes were already described as acquired pili torti et canaliculi. We examined a 78-year-old female patient, with lung carcinoma, taking gefitinib for 15 months. The treatment has no side effects with good tolerance and tumor response. Although the patient had not observed any change on the hairs under the therapy, some specimens were obtained to be examined in natura with scanning electron microscopy. Under low magnification incipient grooving was observed on the hair surface, tortions or angulations of the hair shaft were not found. With higher magnifications the surface grooving was even more evident. Our findings show that gefitinib may cause subclinical hair changes, similar to those described at the ultrastructural level with erlotinib.

Cutaneous collagenous vasculopathy: light and transmission electron microscopy.

Cutaneous collagenous vasculopathy is a rare acquired idiopathic microangiopathy characterized by progressive development of diffuse asymptomatic telangiectasias and histologically by accumulation of collagen type IV around the affected vessels. It is diagnosed by its clinical history, confirmed by light microscopy with collagen-specific immunostaining. We report a case of a patient with extensive acquired telangiectasias on the left arm, clinically resembling unilateral nevoid telangiectasia. Dilated blood vessels with thickened walls were observed in the dermis. Immunohistochemistry with collagen IV antibodies revealed marked collagen deposition around the vessels, confirming the diagnosis. Transmission electron microscopy observed duplicate and triplicate vascular basal membrane associated with deposition of amorphous material around the membranes.

Cutaneous collagenous vasculopathy: light and transmission electron microscopy

Abstract Cutaneous collagenous vasculopathy is a rare acquired idiopathic microangiopathy characterized by progressive development of diffuse asymptomatic telangiectasias and histologically by accumulation of collagen type IV around the affected vessels. It is diagnosed by its clinical history, confirmed by light microscopy with collagen-specific immunostaining. We report a case of a patient with extensive acquired telangiectasias on the left arm, clinically resembling unilateral nevoid telangiectasia. Dilated blood vessels with thickened walls were observed in the dermis. Immunohistochemistry with collagen IV antibodies revealed marked collagen deposition around the vessels, confirming the diagnosis. Transmission electron microscopy observed duplicate and triplicate vascular basal membrane associated with deposition of amorphous material around the membranes.

Scanning Electron Microscopy of Erlotinib-induced Hair Changes: Pili Torti et Canaliculi.

The cutaneous toxicity of the epidermal growth factor receptor inhibitors, such as erlotinib, is associated with a wide range of manifestations, such as papulopustular eruptions, xerosis, paronychia, and changes in the growth pattern of hair and nails. Hair manifestations are seen in 10%-20% of the patients. A female patient taking erlotinib for lung cancer for 8 months noticed that her scalp hair became rough on palpation and that her eyelashes were elongated. Some scalp hairs were cut and proximal and distal portions were examined in natura with scanning electron microscopy. Torsions and important grooving were seen in the proximal portions, but not in distal hair portions. Erlotinib-induced hair changes are pili torti et canaliculi.

Dermatophytosis caused by Microsporum gypseum in infants: report of four cases and review of the literature

Abstract Dermatophytosis caused by Microsporum gypseum is rare, especially in infants, with few published cases. Diagnosis in this age group is frequently delayed. We review the literature and report 4 new cases of tinea of glabrous skin caused by M. gypseum mimicking eczema in infants. Considering new and previously reported cases, half of patients were exposed to sand, emphasizing the importance of this transmission vehicle in this age group. In conclusion, although rare, dermatophytosis by M. gypseum should be part of the differential diagnosis of inflammatory dermatosis in infants. A clinical suspicion and the availability of culture are keys to the diagnosis.

Dermatophytosis caused by Microsporum gypseum in infants: report of four cases and review of the literature.

Dermatophytosis caused by Microsporum gypseum is rare, especially in infants, with few published cases. Diagnosis in this age group is frequently delayed. We review the literature and report 4 new cases of tinea of glabrous skin caused by M. gypseum mimicking eczema in infants. Considering new and previously reported cases, half of patients were exposed to sand, emphasizing the importance of this transmission vehicle in this age group. In conclusion, although rare, dermatophytosis by M. gypseum should be part of the differential diagnosis of inflammatory dermatosis in infants. A clinical suspicion and the availability of culture are keys to the diagnosis.

Extensive hydroa vacciniforme.

Hydroa Vaciniforme is a very rare photodermatosis that is mainly seen in childhood. An 18 year old female student reported that since the age of 5 she has been suffering necrotic lesions and vesicles lesions in exposed areas, leaving asymptomatic varioliform scars, which worsened in summer. Light microscopy showed epidermal necrosis with lymphocytic infiltration . Sunscreens were prescribed with light improvement.

Extensive hydroa vacciniforme / Hidroa vaciniforme extensa

Hydroa Vaciniforme is a very rare photodermatosis that is mainly seen in childhood. An 18 year old female student reported that since the age of 5 she has been suffering necrotic lesions and vesicles lesions in exposed areas, leaving asymptomatic varioliform scars, which worsened in summer. Light microscopy showed epidermal necrosis with lymphocytic infiltration . Sunscreens were prescribed with light improvement.

O Hidroa Vaciniforme é uma fotodermatose muito rara vista geralmente na infância. Uma paciente de 18 anos foi examinada, a qual apresenta lesões vesiculosas e necróticas varioliformes nas áreas fotoexpostas, que evoluem para cicatrizes atróficas, piorando no verão. A microscopia óptica mostrou necrose epidérmica com infiltrado linfocítico. Houve pouca melhora com uso de filtros solares.