Hyperspectral Imaging for Non-invasive Diagnostics of Melanocytic Lesions.

Malignant melanoma poses a clinical diagnostic problem, since a large number of benign lesions are excised to find a single melanoma. This study assessed the accuracy of a novel non-invasive diagnostic technology, hyperspectral imaging, for melanoma detection. Lesions were imaged prior to excision and histopathological analysis. A deep neural network algorithm was trained twice to distinguish between histopathologically verified malignant and benign melanocytic lesions and to classify the separate subgroups. Furthermore, 2 different approaches were used: a majority vote classification and a pixel-wise classification. The study included 325 lesions from 285 patients. Of these, 74 were invasive melanoma, 88 melanoma in situ, 115 dysplastic naevi, and 48 non-dysplastic naevi. The study included a training set of 358,800 pixels and a validation set of 7,313 pixels, which was then tested with a training set of 24,375 pixels. The majority vote classification achieved high overall sensitivity of 95% and a specificity of 92% (95% confidence interval (95% CI) 0.024-0.029) in differentiating malignant from benign lesions. In the pixel-wise classification, the overall sensitivity and specificity were both 82% (95% CI 0.005-0.005). When divided into 4 subgroups, the diagnostic accuracy was lower. Hyperspectral imaging provides high sensitivity and specificity in distinguishing between naevi and melanoma. This novel method still needs further validation.

A Retrospective Study of Treatment of Squamous Cell Carcinoma In situ.

Squamous cell carcinoma in situ is an intra-epidermal malignancy of the skin with potential to progress to invasive carcinoma. Commonly used treatments are surgical excision, cryotherapy, photodynamic therapy, laser ablation, curettage with cautery, radiotherapy, topical 5-fluorouracil, and topical imiquimod. The efficacies of these different treatment modalities are compared in this retrospective study of 239 patients with squamous cell carcinoma in situ diagnosed and treated at our hospital during a period of one year. A total of 263 histologically confirmed in situ lesions were followed up for approximately 8 years. The overall recurrence rate was 6.5%. Surgical excision had the lowest recurrence rate, at 0.8%. Recurrence rates with the less-invasive treatment modalities were markedly higher; cryotherapy 4.7% and photodynamic therapy 18%. Of all recurrences, 65% were carcinoma in situ and 35% squamous cell carcinomas. Twenty-three patients had actinic keratosis in the area treated, but these were not counted as recurrences. In conclusion, excisional surgery is the gold standard treatment for squamous cell carcinoma in situ, although it has limitations. Less invasive methods may sometimes be preferred.

[Diagnosis and treatment of actinic keratosis]. / Aktiinisen keratoosin diagnostiikka ja hoito.

Actinic keratoses are premalignant skin lesions with the risk of converting into squamous cell carcinoma, and therefore they should be treated. Treatment modalities include cryotherapy, photodynamic therapy, carbon dioxide laser and also topical treatments such as imiquimode, ingenol mebutate, 5-fluorouracil and diclophenac. In the future, the treatment of actinic keratosis can be more often done in primary health care. The most favorable treatment modality depends on patient age, general health, and the thickness, size and localization of the lesion.

[Treatment of hemangiomas]. / Hemangioomien hoito.

Hemangioma is the most common benign tumor in infancy. Over 90% of hemangiomas require no treatment, but there is a need to recognize those that may require even quick measures to secure vital functions or normal development of organs. Propranolol has established itself as the first-line treatment. Pulsed dye laser has proven effective in the treatment of ulcerated hemangiomas. Corticosteroid therapy is applied only rarely, but surgical treatment or angiography and embolization therapy associated with it may sometimes be indicated.