Differentiation of Basal Cell Carcinoma Subtypes in Multi-Beam Swept Source Optical Coherence Tomography (MSS-OCT)
May 2016 | Volume 15 | Issue 5 | Original Article | 545 | Copyright © May 2016
Adam Meekings BSc,a Sarah Utz BA,d Martina Ulrich MD,f Amanda Bienenfeld BA,d,e Naveen Nandanan MD,e Juliya Fisher MD,c Gordon McKenzie PhD,b Daniel M. Siegel MD FAAD,c Eleanor Feldman BA,c and Orit Markowitz MD FAADc
aGuy’s and St Thomas’ NHS Foundation Trust, London, UK
bMichelson Diagnostics Ltd, UK
cSUNY Downstate Medical Center, Brooklyn, NY
dMount Sinai Medical Center, New York, NY
eNY Harbor Healthcare System, Brooklyn, NY
fDermatologie am Regierungsviertel, Berlin, Germany
Abstract
BACKGROUND: Optical coherence tomography (OCT) is a technique that enables real-time in-vivo examination of tissue. This technology provides the clinician with the potential to use a non-invasive tool in the identification and diagnosis of many skin lesions. However, the diagnostic features of basal cell carcinoma have not yet been described with comparison to their histopathology.
OBJECTIVES: To identify and describe key features of basal cell carcinoma (BCC) and its subtypes as they present in multi-beam Swept Source – OCT (MSS-OCT), and to correlate those against conventional histopathology.
METHODS: A total of 40 lesions were assessed by MSS-OCT prior to biopsy. 60-slice OCT images of the lesions were obtained and correlated with histology sections taken in the same plane. OCT scans were assessed retrospectively by a panel to determine the OCT criteria for BCC and its subtypes.
RESULTS: The following diagnostic criteria were identified: hyporeflective ovoid structures (40/40), dark halo boundaries (38/40), epidermal thinning (28/40), and collagen compression (14/40). Lesional tissue also showed a destruction of layers when compared to the surrounding normal tissue. In addition to the shared criteria, other subtypes showed distinct diagnostic criteria.
CONCLUSION: With its higher sensitivity, using MSS-OCT allowed for non-invasive, accurate identification of the key diagnostic features of BCC and its subtypes with high correlation to the histopathologic features found with biopsy.
J Drugs Dermatol. 2016;15(5):545-550.
INTRODUCTION
Basal cell carcinoma (BCC) is the most prevalent skin cancer in fair skin types,1,2 with incidence rising steeply across the western world.3 The current definitive diagnostic procedure is histopathological examination of tissue, however there is an increasing need for a non-invasive supplementary diagnostic method for early detection of lesions, non-invasive treatment options.
Optical coherence tomography (OCT) has been suggested to address this growing concern. At a most basic level, OCT has been shown to allow delineation of lesional from normal tissue in vivo.21,29 A number of prior studies have demonstrated correlation of OCT images with histopathology, showing accurate characterization of actinic keratoses (AK), in situ squamous cell carcinomas (SCC), and BCC’s.12,27,28 It has also been used to monitor the therapy of non-melanoma skin cancer.18,21,30-36
BCC has been investigated using many different OCT systems in the past years, however no study has sought to determine
diagnostic criteria.12,13,18,21-26 OCT enables precise tumor visualization of superficial BCCs to a depth of 1-2 mm, with accurate measurement of tumor depth against histology demonstrated to 1 mm by Coleman. 26 A Bland-Altman plot compared the accuracy of OCT vs histology, and found that OCT provided good agreement with histology to a lesion depth of 1 mm.26
OCT is capable of visualizing tumor margins that extend beyond apparent surface changes.21, 23, 37 These measurements are useful when identifying lesions suitable for non-invasive therapy. Additionally, correlation between cellular palisading and clefting in histology, and a hyporeflective band at the periphery of cell nests seen in both superficial and nodular BCCs, has also been demonstrated.26
Thus, this visualization might in some cases allow a biopsy to be avoided entirely, with obviously superficial lesions potentially treated non-invasively. Alternatively, obviously invasive
