Dermoscopic Features of Basal Cell Carcinoma on the Lower Limbs: A Chameleon!

Abstract

Background:Lower limbs represent an uncommon location for basal cell carcinoma (BCC) and only few reports have described dermoscopic features of BCC in this body site. Since BCCs of the lower limbs frequently display nonclassic BCC dermoscopic criteria, they can simulate other benign or malignant lesions. Objective: Our aim was to describe the dermoscopic features of BCC located on lower limbs and to define which criteria were more associated with their benignor malignant-looking appearance. Methods: We conducted a retrospective study enrolling consecutive patients with histologically confirmed BCCs of the lower limbs. Lesions were classified in 7 categories according to the clinical and dermoscopic global appearance. Clear BCC, squamous cell carcinoma (SCC) or Bowen disease-like, Kaposi disease-like, melanoma-like, and aspecific pattern were considered malignant-looking lesions; however, seborrheic keratosis-like and dermatofibroma-like were considered benign-looking. To define which dermoscopic criteria were independently associated with benign-or malignant-looking appearance, we conducted a multivariate logistic regression analysis. Results:A total of 81 BCCs were enrolled: 18 (22%) were benign-looking lesions (of which 11 were seborrheic keratosis-like and 7 dermatofibroma-like) and 63 (78%) were malignant-looking BCCs (of which 24 were clear-cut BCCs, 23 SCC-like, 2 Kaposi disease-like, 9 melanoma-like, and 5 had aspecific pattern). Multivariate regression analysis showed that erosions/ulceration and vessels were independently associated with malignant-looking appearance. The most represented vessels were glomerular and polymorphic, which are more frequently encountered in SCC, together with ulceration. Conclusion: BCC of the lower legs frequently simulates other benign or malignant lesions, with SCC being the main differential diagnosis.

Diagnostic accuracy of ex vivo fluorescence confocal microscopy in Mohs surgery of basal cell carcinomas: a prospective study on 753 margins

“…2 In the last few years, new tools have been developed in an attempt to speed up and obtain a more efficient skin cancer diagnosis pre-and intraoperatively. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] Reflectance confocal microscopy has been successfully applied to skin cancer diagnosis in the clinical setting, with an emphasis on BCC. 10,11,13,15 However, reflectance confocal microscopy is mainly used for preoperative in vivo skin cancer diagnosis.…”

“…Ex vivo FCM is a new imaging tool that offers an attractive alternative to conventional frozen histology for the detection of margins in freshly excised tissue. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]20,[33][34][35][36][37][38] It was initially applied to skin cancer, in particular BCCs, and later to solid tumours in pivotal studies. [21][22][23][24][25][26][27][28][29][30][31][32] Basically, FCM scans a given surgical specimen and provides grey-scale high-resolution images that are automatically stitched together to create 'mosaics'.…”

Disguised basal cell carcinomas: how to track them down with reflectance confocal microscopy

“…1 The typical dermoscopic algorithm for the diagnosis of BCC includes the following: erosion or ulceration, maple leaf-like areas, blue-grey globules, ovoid nests, spoke wheel-like areas, brown dots and arborizing vessels. [4][5][6][7] Reflectance confocal microscopy (RCM) is an emerging noninvasive technique for the in vivo imaging of the skin. 3 However, atypical clinical presentation and misleading dermoscopy can sometimes make the diagnosis of BCC particularly challenging.…”

“…An important distinguishing criterion, however, is the histopathological phenomenon of verruciform xanthoma (VX). [6][7][8][9] Here, we want to draw the clinicians' attention to a peculiar clinical variant of VX that is highly characteristic, and perhaps even pathognomonic, of the CHILD naevus, and we propose the name 'tympanoxyloid VX', and we found three reports on telephalangeal VX in patients with CHILD syndrome ( Table 1). 3 The enlarged papillary areas are filled with foamy histiocytes containing lipids reflecting mutational inactivation of the 3b-hydroxysteroid dehydrogenase (NSDHL) gene located at Xq28, with blockade of cholesterol production.…”

“…3 However, atypical clinical presentation and misleading dermoscopy can sometimes make the diagnosis of BCC particularly challenging. [4][5][6][7] Reflectance confocal microscopy (RCM) is an emerging noninvasive technique for the in vivo imaging of the skin. We present a series of five cases of BCCs where dermoscopy mimicked other types of benign and malignant lesions and the diagnosis was unveiled by RCM.…”