Dual contrastive learning based image-to-image translation of unstained skin tissue into virtually stained H&E images.

Staining is a crucial step in histopathology that prepares tissue sections for microscopic examination. Hematoxylin and eosin (H&E) staining, also known as basic or routine staining, is used in 80% of histopathology slides worldwide. To enhance the histopathology workflow, recent research has focused on integrating generative artificial intelligence and deep learning models. These models have the potential to improve staining accuracy, reduce staining time, and minimize the use of hazardous chemicals, making histopathology a safer and more efficient field. In this study, we introduce a novel three-stage, dual contrastive learning-based, image-to-image generative (DCLGAN) model for virtually applying an "H&E stain" to unstained skin tissue images. The proposed model utilizes a unique learning setting comprising two pairs of generators and discriminators. By employing contrastive learning, our model maximizes the mutual information between traditional H&E-stained and virtually stained H&E patches. Our dataset consists of pairs of unstained and H&E-stained images, scanned with a brightfield microscope at 20 × magnification, providing a comprehensive set of training and testing images for evaluating the efficacy of our proposed model. Two metrics, Fréchet Inception Distance (FID) and Kernel Inception Distance (KID), were used to quantitatively evaluate virtual stained slides. Our analysis revealed that the average FID score between virtually stained and H&E-stained images (80.47) was considerably lower than that between unstained and virtually stained slides (342.01), and unstained and H&E stained (320.4) indicating a similarity virtual and H&E stains. Similarly, the mean KID score between H&E stained and virtually stained images (0.022) was significantly lower than the mean KID score between unstained and H&E stained (0.28) or unstained and virtually stained (0.31) images. In addition, a group of experienced dermatopathologists evaluated traditional and virtually stained images and demonstrated an average agreement of 78.8% and 90.2% for paired and single virtual stained image evaluations, respectively. Our study demonstrates that the proposed three-stage dual contrastive learning-based image-to-image generative model is effective in generating virtual stained images, as indicated by quantified parameters and grader evaluations. In addition, our findings suggest that GAN models have the potential to replace traditional H&E staining, which can reduce both time and environmental impact. This study highlights the promise of virtual staining as a viable alternative to traditional staining techniques in histopathology.

Subacute cutaneous lupus erythematosus with a psoriasiform presentation: A diagnostic clinical conundrum.

Key Clinical Message: For practitioners experiencing worsening psoriasis, subacute cutaneous lupus erythematosus (SCLE) with a psoriasiform presentation should be ruled out. Initial treatment for a presumptive diagnosis of psoriasis using hydroxychloroquine or ultraviolet phototherapy may cause SCLE to worsen. Abstract: Psoriasiform subacute cutaneous lupus erythematosus is an unusual presentation scarcely reported in literature. We report a case of a 54-year-old man who presented with an itchy, papulosquamous rash of the upper extremities and face for 7 months. The initial physical examination revealed the classical morphology of psoriasis. One and a half years after the diagnosis of clinical worsening, the patient noticed a new papular eruption on the right posterior upper arm. A skin biopsy was performed, confirming a diagnosis of subacute cutaneous lupus erythematosus. This case report highlights the importance of considering rare presentations of cutaneous lupus erythematosus and therapeutic challenges in management.