Immediate diagnosis of cutaneous metastases with optical coherence tomography, line‐field confocal optical coherence tomography and dermoscopy: A case series

Background Cutaneous metastases (CM) are a frequent finding in the follow‐up of malignant tumours. Objectives CM were examined with dermoscopy, optical coherence tomography (OCT), dynamic OCT and line‐field confocal OCT (LC‐OCT) to describe common findings. Methods In the University Hospital Carl Gustav Carus Dresden, Germany, 18 patients with 61 CM were examined with dermoscopy. CM (n = 43, 31 melanoma metastases, two metastases of renal carcinoma, five metastases of cutaneous squamous cell carcinoma and five metastases of pleomorphic dermal sarcoma) were examined with OCT (VivoSight® Michelson Diagnostics). Additional 18 melanoma metastases were examined with LC‐OCT (deepLive™; Damae Medical). Results CM were localized on the head, trunk, neck and limbs. Dermoscopy patterns were angioma‐like, nevus‐like nonglobular, nevus‐like globular, blue nevus‐like and unspecific. CM showed an ulceration, hyperkeratosis with increased entrance signal and disturbed architecture of the epidermis in OCT. In deeper metastases, the dermoepidermal junction (DEJ) was normal; in most cases it was disturbed. CM were visible as subepidermal hyporeflective roundish area, with septae, with either clear margin and shadowing or blurred margin. DOCT showed dot, coiled, serpiginous and branched vessels; there was a disarray in size and distribution and vessels were converging on the centre of the metastasis. In LC‐OCT, CM showed enhanced entrance signal and disturbed architecture of a thinned epidermis, ulceration, atypical honeycomb or cobblestone pattern as well as a broken DEJ. In the dermis, a hyporeflective roundish area with clusters of hyporeflective cells with septae, clear margin and clefting or blurred margin was visible; the hyporeflective area was surrounded by bundles of connective tissue. Subepidermal vessels differentiated in size and distribution. Inflammatory, dendritic and pagetoid cells were visible. Conclusions OCT and LC‐OCT may be useful tools for immediate diagnosis, localization of CM and monitoring under treatment in addition to conventional methods like ultrasound and histopathology. Cutaneous metastases (CM) in optical coherence tomography (OCT) were visible as subepidermal hyporeflective roundish areas with septae, with clear or blurred margin and shadowing. Dynamic OCT showed dot, coiled, serpiginous and branched vessels converging in the centre. Line‐field confocal OCT showed a thinned epidermis with atypical honeycomb or cobblestone pattern and a broke