Reflectance confocal microscopy of Pigmented Bowen's disease: misleading dendritic cells

Bowen's disease of the penile shaft presenting as a pigmented macule: dermoscopy, reflectance confocal microscopy and histopathological correlation

The penile localization of pigmented Bowen's disease has been rarely reported and has been mostly related to human papillomavirus infection. Early diagnosis and treatment are important to prevent progression to invasive squamous cell carcinoma. However, diagnosis can be challenging because it may be difficult to distinguish from melanoma, even using dermoscopy. Reflectance confocal microscopy may be useful in suggesting the bedside diagnosis before the histopathological confirmation. A case of penile pigmented Bowen's disease is described along with its dermoscopy and reflectance confocal microscopy findings and their correlation with histopathology.

Reflectance Confocal Microscopy of Pigmented Bowen's Disease: A Case Series of Difficult to Diagnose Lesions

Pigmented Bowen's disease is a rare variant of in situ squamous skin cell carcinoma. It mainly affects patients between 60 and 70 years of age. Its clinical features include well-demarcated, pigmented plaque arising in photo-exposed areas of the body. The best-characterized feature of the disease by histological examination is the presence of atypical keratinocytes, hyperpigmentation of the epidermis with trans-epidermal elimination of melanin and dermal melanophages. Precise diagnosis is often difficult, both clinically and dermoscopically, as Bowen's disease is often mistaken with keratinocyte tumors such as solar lentigines, seborrheic keratosis, Bowenoid papulosis, pigmented basal cell carcinoma, pigmented actinic keratosis; or even melanocytic lesions such as melanocytic nevus, pigmented epithelioid melanocytoma, and melanoma. Precise diagnosis often requires biopsy and histopathological examination of the tissue. Reflectance confocal microscopy is a noninvasive technique to diagnose pigmented skin lesions. To date, not much data are available regarding its use in the diagnosis of pigmented Bowen's disease. Herein, we report a well-represented case series of pigmented Bowen's disease imaged using dermoscopy and reflectance confocal microscopy.

Reflectance confocal microscopy for noninvasive examination of nonmelanocytic tumors and virus-associated skin lesions in organ transplant recipients

BACKGROUND

Drug-induced immunosuppression is necessary to prevent rejection of the foreign organ in transplanted patients, but neoplastic and virus-associated skin diseases are frequent complications. Reflectance confocal microscopy (RCM) recently emerged as a promising tool for the early diagnosis of skin lesions.

MATERIALS AND METHODS

A total of 61 skin lesions, among them 20 basal cell carcinomas, six Bowen's diseases, 23 actinic keratoses, and 12 verrucae, were analyzed. All lesions were clinically evaluated followed by RCM evaluation by two independent dermatologists and histological examination.

RESULTS

For the diagnosis of basal cell carcinoma, a sensitivity of 100% by both investigators (INV I + II) and a specificity of 100% by INV I and 80% by INV II were achieved. The sensitivity average rate for RCM features reached by both investigators ranged between 60% and 100%, and the specificity between 55% and 90%. For the diagnosis of actinic keratosis, a concordant sensitivity of 94.4% and a specificity of 80% (INV I) and 60% (INV II) were detected. The sensitivity average rate of specific RCM criteria ranged between 72.3% and 97.2%, whereas specificity ranged between 20% and 90%. Regarding verrucae, RCM confirmed the histological diagnosis with a sensitivity of 85.7% (INV I) and 100% (INV II), while specificity was 100% and 80%, respectively.

CONCLUSION

Reflectance confocal microscopy resulted to be a reliable tool for the noninvasive diagnosis of neoplastic and virus-associated skin changes in organ transplant recipients. Nevertheless, given the frequency and diagnostic complexity of the hyperkeratotic lesions occurring post-transplantation, larger cohorts of patients are required to confirm and consolidate these findings.

Non-invasive imaging techniques for the in vivo diagnosis of Bowen's disease: Three case reports

Bowen's disease (BD) is a relatively frequent non-melanoma skin cancer occurring mostly in elderly people. Until now, the usual way to establish the diagnosis is histopathological examination of a skin biopsy. Dermoscopy and reflectance confocal microscopy (RCM) are modern alternative methods that can be used as quick and non-invasive diagnostic techniques and as follow-up instruments in cases in which a conservative treatment is chosen for the management of BD. There are no very specific dermoscopic criteria for the diagnosis of this disease, but some dermoscopic features (scaly surface, vascular structures and pigmentation) can be found more frequent and can be helpful for the diagnosis. RCM of BD shows an acanthotic epidermis with two types of targetoid cells: the first, a large cell with bright center and dark peripheral halo, the second, a cell with dark center and a bright rim surrounded by a dark hallo, related with dyskeratotic cells on histological examination. BD management could be improved by using non-invasive, in vivo imaging techniques that allow a fast and easy diagnosis and can be used as follow-up tools. However, larger studies are necessary for the validation of our observations.

The role of reflectance confocal microscopy in a case of Bowen's disease difficult to diagnose

There have been limited reports describing reflectance confocal microscopy (RCM) features of Bowen’s disease (BD). Herein, we describe the RCM features of a pigmented BD with atypical dermoscopic features, mimicking a melanoma. This case highlights the importance of RCM in a challenging BD.