Diagnostic accuracy of a new ex vivo confocal laser scanning microscope compared to H&E‐stained paraffin slides for micrographic surgery of basal cell carcinoma

Abstract

Confocal laser scanning microscopy is a time-saving and very effective alternative to classical paraffin-embedded or frozen sections. Patient treatment could be improved due to shorter hospital stays or faster outpatient therapy due to reduced intervals between surgical stages. Diagnostic accuracy of the microscope used still must be improved.

Routine application of ex vivo confocal laser scanning microscopy with digital staining for examination of surgical margins in basal cell carcinomas

“…Learning curves for confocal laser scanning microscopy have been described elsewhere [13, 16, 23, 24]. Even though investigators needed only a two‐day introduction to use the appliance with confidence, we did notice that image quality improved over the course of our study, and there was a trend towards requiring shorter periods of time.…”

Ex vivo confocal microscopy: revolution in fast pathology in dermatology

“…Different staining methods have been used to enhance the contrast of cell structures in ex vivo CM with no damage to conventional histopathology preparation (Table 3). 14,17,[22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] Correlation of ex vivo confocal microscopy and normal skin histology Ex vivo confocal images allow a good correlation with conventional histology with H&E ( Figure 2). In a recent study by Sch€ u€ urmann et al, 38 using the VivaScope V2500, they found that the following cutaneous and subcutaneous structures are excellently displayed in the images, with only minimal differences compared with H&E slides: every layer of the epidermis, collagen and elastic tissue; lymphatic and capillary vessels; hair follicles and other skin appendages; eccrine and sebaceous glands; subcutaneous fat; elastic cartilage and muscle fibres.…”

“…23 In a recent study with an FCM device with different samples from punch biopsies from Mohs specimens, Peters et al reported a median total time to generate and evaluate a Basal cell carcinoma, 24,[43][44][45][46][47] squamous cell carcinoma, 26,45,[48][49][50] dermatofibrosarcoma, 41 melanocytic lesions, 35,51,52,[54][55][56]77 tumours in special sites 55,62,78 (eyelid tumours, tumours of the conjunctiva, tumours of the nails) Other tumours: breast, prostate, brain, thyroid, oesophagus, stomach, colon, lung, lymph node, cervix, oral mucosa and larynx [69][70][71][72] Diagnosis of infections: mucormycosis, 63 dermatophytosis, 64 herpes virus, 65 molluscum contagiousm, 66 aspergillosis 79 Inflammatory skin diseases 36,37,68 (vasculitis, bullous diseases, psoriasis, lichen planus, discoid lupus erythematosus) Skin fillers 67 confocal laser scanning microscopy (CLSM) image of 5Á17 min (range 2Á05-20Á17). 34 Most of the ex vivo CM studies were conducted on BCCs. Subsequently, this technique has been used for other epithelial tumours, melanocytic tumours, dermatofibrosarcoma and Paget disease.…”

“…32,42 The overall sensitivity and specificity of fluorescence-mode ex vivo CM for detecting BCC with narrow or incomplete margins are 88-96Á6% and 89Á2-99%, respectively. 24,34,[43][44][45][46][47] Table 6 presents the results of diagnostic accuracy in different studies with CM on fresh tissue. Sensitivity was inferior to specificity in three studies, equal in one, and superior in three when compared with conventional histopathology with frozen or paraffin sections.…”

“…However, it has been shown that confocal imaging of fresh tissue can avoid some problems in the identification of the tumour compared with classic methods. 34 Table 7 summarizes the reasons for lack of correlation with conventional histopathology.…”