Banzhaf Christina, Jemec Gregor B E
Department of Dermatology, Roskilde Hospital, Health Sciences Faculty, University of Copenhagen, Copenhagen, Denmark.
Case Rep Dermatol. 2012 Jan;4(1):14-8. doi: 10.1159/000336000. Epub 2012 Jan 30.
To investigate and compare the presentation of granulomatous lesions in optical coherence tomography (OCT) images and compare this to previous studies of nonmelanoma skin tumors.
Two patients with granulomas, tophi and granuloma annulare (GA), respectively, were photographed digitally, OCT-scanned and biopsied in the said order. Normal skin was OCT-scanned for comparison, but not biopsied. The OCT images from each lesion were compared with their histologic images as well as with OCT images with similar characteristics obtained from nonmelanoma skin tumors.
The OCT images of the tophi showed hyperreflective, rounded cloud-like structures in dermis, their upper part sharply delineated by a hyporeflective fringe. The deeper areas appeared blurred. The crystalline structures were delineated by a hyporeflective fringe. OCT images of GA showed two different structures in dermis: a hyporeflective rounded one, and one that was lobulated and wing-like.
Granulomatous tissue surrounding urate deposits appeared as a clear hyporeflective fringe surrounding a light, hyperreflective area. The urate crystals appeared as hyperreflective areas, shielding the deeper part of dermis, meaning OCT could only visualize the upper part of the lesions. The lobulated, wing-like structure in GA may resemble diffuse GA or a dense lymphocytic infiltrate as seen on histology. The rounded structure in GA may represent an actual granuloma or either diffuse GA or a dense lymphocytic infiltrate as described above. This case suggests that OCT images granulomatous tissue as absorbent, hyporeflective areas, and urate crystals appear as reflective areas, obscuring the underlying tissue. In GA a new image shape looking like a wing has been found. The frequency, specificity and sensitivity of this new pattern in OCT imaging will require further studies.
研究并比较光学相干断层扫描（OCT）图像中肉芽肿性病变的表现，并将其与先前关于非黑素瘤皮肤肿瘤的研究进行比较。
分别对两名患有肉芽肿、痛风石和环状肉芽肿（GA）的患者按上述顺序进行数码拍照、OCT扫描及活检。对正常皮肤进行OCT扫描以作比较，但未进行活检。将每个病变的OCT图像与其组织学图像以及从非黑素瘤皮肤肿瘤获得的具有相似特征的OCT图像进行比较。
痛风石的OCT图像显示真皮内有高反射性的圆形云状结构，其上部由低反射性边缘清晰界定。较深区域显得模糊。晶体结构由低反射性边缘勾勒。GA的OCT图像在真皮内显示出两种不同结构：一个低反射性圆形结构和一个分叶状、翼状结构。
尿酸盐沉积物周围的肉芽肿组织表现为围绕浅色高反射区域的清晰低反射边缘。尿酸盐晶体表现为高反射区域，遮蔽了真皮深层，这意味着OCT只能显示病变的上部。GA中的分叶状、翼状结构可能类似于组织学上所见的弥漫性GA或密集淋巴细胞浸润。GA中的圆形结构可能代表实际的肉芽肿或上述弥漫性GA或密集淋巴细胞浸润。该病例表明，OCT将肉芽肿组织成像为吸收性低反射区域，尿酸盐晶体表现为反射区域，掩盖了下层组织。在GA中发现了一种新的类似翅膀的图像形状。这种新模式在OCT成像中的频率、特异性和敏感性需要进一步研究。
