Three-Dimensional Observations of an Aperiodic Oscillatory Gliding Behavior in Myxococcus xanthus Using Confocal Interference Reflection Microscopy

Two-photon fluorescence microscopy and confocal reflectance microscopy were compared to detect intracellular gold nanorods in rat basophilic leukaemia cells. The two-photon photoluminescence images of gold nanorods were acquired by an 800 nm fs laser with the power of milliwatts. The advantages of the obtained two-photon photoluminescence images are high spatial resolution and reduced background. However, a remarkable photothermal effect on cells was seen after 30 times continuous scanning of the femto-second laser, potentially affecting the subcellular localization pattern of the nanorods. In the case of confocal reflectance microscopy the images of gold nanorods can be obtained with the power of light source as low as microwatts, thus avoiding the photothermal effect, but the resolution of such images is reduced. We have noted that confocal reflectance images of cellular gold nanorods achieved with 50 microW 800 nm fs have a relatively poor resolution, whereas the 50 microW 488 nm CW laser can acquire reasonably satisfactory 3D reflectance images with improved resolution because of its shorter wavelength. Therefore, confocal reflectance microscopy may also be a suitable means to image intracellular gold nanorods with the advantage of reduced photothermal effect.

Investigating The Network Structure Of Type I Collagen As A Function Of Temperature And Concentration Via Confocal Microscopy

Objective To evaluate the diagnostic value of dermoscopy and reflectance confocal microscopy (RCM) alone or in combination for melanocytic nevus. Methods A total of 37 patients with clinically diagnosed melanocytic nevus were collected. Skin lesions were firstly examined by dermoscopy and RCM, then were resected to be subjected to histopathological examination for final diagnosis. The imaging features of melanocytic nevus were summarized. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of different skin imaging techniques were calculated, and the consistency was analyzed between skin imaging techniques and histopathological examination. Results Based on the dermoscopic and RCM findings, 2 kinds of nevus cells with different morphological features were observed in the dermis of intradermal nevus. One kind of nevus cells was characterized by a non-fusional, highly-refractive round structure in the papillary dermis under RCM, and by a brown or light brown homogenous pattern under dermoscopy, which was observed in 5 skin lesions. The other kind of nevus cells appeared as irregular, highly-refractive cell clumps in the papillary dermis under RCM, and by a cobblestone or globular pattern under dermoscopy, which was observed in 31 skin lesions. For the diagnosis of melanocytic nevus, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of RCM combined with dermoscopy were 91.7%, 87.5%, 90.9%, 97.1% and 70% respectively, those of RCM were 86.1%, 75%, 84%, 93.9% and 54.5% respectively, and those of dermoscopy were 77.8%, 87.5%, 75%, 96.3% and 41.2% respectively. All the diagnostic indices of RCM combined with dermoscopy were higher than those of RCM or dermoscopy alone, except that the specificity was equal to that of dermoscopy alone. RCM showed higher sensitivity, accuracy and negative predictive value, but lower specificity and positive predictive value compared with dermoscopy. There were no significant differences in the diagnostic yield in melanocytic nevus between RCM combined with dermoscopy or RCM alone and histopathological examination (χ2= 0.25, 0.57, P= 0.63, 0.45, Kappa value= 0.72, 0.53, respectively) . However, a significant difference in the diagnostic yield in melanocytic nevus was observed between dermoscopy and histopathological examination (χ2= 5.81, P= 0.012) . Conclusion RCM combined with dermoscopy shows higher diagnostic accuracy for melanocytic nevus compared with RCM or dermoscopy alone. Key words: Nevus; Microscopy, confocal; Dermoscopy; Pathology, clinical; Diagnostic techniques and procedures

Dermatoscopy increases both the sensitivity and specificity of melanoma diagnosis. Reflectance confocal microscopy (RCM) is a noninvasive technique that complements dermatoscopy in the evaluation of equivocal lesions at cellular resolution. To determine prospectively the potential impact of confocal microscopy when implemented in a routine melanoma diagnosis workflow. Patients referred to a single melanoma clinic were consecutively enrolled. At dermatoscopy, patients were referred to one of the following pathways: (i) no further examination or (ii) RCM examination. On examination atypical lesion(s) were referred for either (a) RCM documentation (lesions with consistent suspicious clinical/dermatoscopic criteria, already qualified and scheduled for surgical excision) or (b) RCM consultation for equivocal lesions, where RCM diagnosis would determine lesion definite outcome (excision or digital follow-up). Reflectance confocal microscopy examination was performed for 41% of 1005 patients enrolled. In two-thirds of these cases RCM influenced the lesion outcome. The systematic application of RCM for equivocal lesions saved over 50% of benign lesions from unnecessary excision. The number needed to excise a melanoma was 6·8 with RCM examination, compared with a hypothetical 14·6 without RCM evaluation. Reflectance confocal microscopy as a second-level examination to dermatoscopy proved to be highly accurate in diagnosis and reduced the number of unnecessary excisions. Improved accuracy, considering that RCM enabled the detection of the six melanomas (2%) in the group of 308 lesions eligible for follow-up, also minimizes the risk of referring a melanoma to digital dermatoscopy monitoring, and potentially losing the patient to follow-up.

As described in detail in the previous chapters, confocal reflectance microscopy has demonstrated the ability to provide images of in vivo or unprocessed ex vivo tissue with sufficient cellular and morphological information to enable the diagnosis of a broad range of dermatological conditions. In many ways, confocal reflectance microscopy provides to clinical dermatology what medical ultrasound did for radiology: a real-time diagnostic imaging modality available in the clinic at the time of care. Although confocal reflectance microscopy and ultrasound operate at different tissue resolutions and imaging depths, there are many analogies between these two modalities. Like ultrasound, a trained observer interprets the image information to make a diagnosis and determine the next steps in care. Tissue information is typically presented as gray scale images. Real-time information can be recorded in cross-sectional image stacks or movies. Examinations can be interpreted in real time or stored and reviewed later or remotely. Like ultrasound, the clinical ergonomics of the reflectance confocal microscope can limit its clinical application and frequency of use. Finally, just as in the case of ultrasound systems, the underlying physics and technology of clinical reflectance confocal microscopes will evolve and improve. In this section we will discuss the progress in development of reflectance confocal microscopy to: (1) enhance clinical ergonomics, (2) improve image fidelity, (3) increase image specificity, and (4) provide for deeper imaging.

Lentigo maligna (LM) is a clinical, pathologic, and therapeutic challenge with a higher risk of local recurrence than other types of melanoma correctly treated and also carries the cosmetically sensitive localization of head and neck. To determine whether in vivo reflectance confocal microscopy (RCM) mapping of difficult LM cases might alter patient care and management. Analysis of LM and LM melanoma (LMM) in a series of patients with large facial lesions requiring complex reconstructive surgery and/or recurrent or poorly delineated lesions at any body sites were investigated. Two tertiary referral melanoma centers in Sydney, Australia. Thirty-seven patients with LM (including 5 with LMM) were mapped with RCM. Fifteen patients had a recurrent LM, including 9 with multiple prior recurrences. The LM was classified amelanotic in 10 patients, lightly pigmented in 9, and partially pigmented in 18. The RCM images were obtained in 4 radial directions (allowing for anatomic barriers) for LM margin delineation using an RCM LM score previously described by our research team. Differences in the margin of LM as determined by RCM vs dermoscopy vs histopathologic analysis. Seventeen of 29 patients (59%) with dermoscopically visible lesions had subclinical (RCM-identified) disease evident more than 5 mm beyond the dermoscopy margin (ie, beyond the excision margin recommended in published guidelines). The RCM mapping changed the management in 27 patients (73%): 11 patients had a major change in their surgical procedure, and 16 were offered radiotherapy or imiquimod treatment as a consequence of the RCM findings. Treatment was surgical in 17 of 37 patients. Surgical excision margins (based on the RCM mapping) were histopathologically involved in only 2 patients, each of whom had an LM lesion larger than 6 cm. In vivo RCM can provide valuable information facilitating optimal patient care management.

Latest advances in confocal microscopy of skin cancers toward guiding patient care: a Mohs surgeon’s review and perspective About 350 publications worldwide have reported the ability of reflectance confocal microscopy (RCM) imaging to detect melanocytic skin lesions in vivo with specificity of 84-88% and sensitivity of 71-92%, and non-melanocytic skin lesions with specificity of 85-97% and sensitivity 100-92%. Lentigo maligna melanoma can be detected with sensitivity of 93% and specificity 82%. While the sensitivity is comparable to that of dermoscopy, the specificity is 2X superior, especially for lightly- and non-pigmented lesions. Dermoscopy combined with RCM imaging is proving to be both highly sensitive and highly specific. Recent studies have reported that the ratio of equivocal (i.e., would have been biopsied) lesions to detected melanomas dropped by ~2X when guided by dermoscopy and RCM imaging, compared to that with dermoscopy alone. Dermoscopy combined with RCM imaging is now being implemented to guide noninvasive diagnosis (to rule out malignancy and biopsy) and to also guide treatment, with promising initial impact: thus far, about 3,000 patients have been saved from biopsies of benign lesions. These are currently under follow-up monitoring. With fluorescence confocal microscopy (FCM) mosaicing, residual basal cell carcinomas can be detected in Mohs surgically excised fresh tissue ex vivo, with sensitivity of 94-97% and specificity 89-94%. FCM mosaicing is now being implemented for guiding Mohs surgery. To date, about 600 Mohs procedures have been performed, guided with mosaicing, and with pathology being performed in parallel to confirm the final outcome. These latest advances demonstrate the promising ability of RCM and FCM to guide patient care.

Investigating the dynamic crosstalk between the tumor-immune microenvironment (TiME) and microvasculature in vivo in patients can lead to important insights into the underlying biology, help identify tumor phenotypes and reveal attractive druggable targets. Dynamic non-invasive label-free imaging of TiME and microvasculature in real-time directly in patients using reflectance confocal microscopy (RCM) was investigated on 60 skin cancer patients (basal cell carcinoma, BCC; squamous cell carcinoma, SCC), followed by automated and machine-learning based quantification of TiME and microvasculature features such as vascular density, leukocyte trafficking and immune cell density. Manual (two readers) and histopathological evaluation (dermatopathologist) of these features was also performed. Molecular correlation of imaging features and phenotypes was performed using anti-CD3/anti-CD20 IHC staining for tertiary lymphoid structures (TLS) and total lymphocyte density (n=33), flow cytometry for immune cells (n=3), and differential RNA expression (n=14). Correlation of RCM features and phenotypes at baseline (before treatment) with treatment response was also evaluated on 9 cancer lesions undergoing topical immunotherapy imiquimod. High agreement for feature presence on RCM and Histology, and manual and automated RCM features was observed. Unsupervised clustering on total TiME and microvasculature features on RCM using principal component analysis (PCA) indicates four distinct tumor phenotypes (PCA 1). The phenotype with high inflammation, high trafficking and higher density of vessels or the denoted ‘hot' phenotype correlated with higher activated CD8+ Granzyme B+ cells (67% of total CD8+cells). The clustering pattern on RCM was compared to TLS and lymphocyte density (PCA 2) and gene expression following CIBERSORT analysis (PCA 3). The clustering in RCM correlated better with gene expression (PCA 1 and 3, 100% agreement) than TLS and lymphocyte density (PCA 1 and 2, 86% agreement). The ‘hot' phenotype in RCM correlated with higher immune gene signatures and higher TLS/lymphocyte density. Increased plasma, CD8, activated CD4 memory and activated NK cells, M1 macrophages and monocytes, along with up-regulation of JAK-STAT, chemokine and cell adhesion signaling cascade were found in the ‘hot' RCM phenotype. Statistical modeling for correlating phenotypes with treatment outcomes was performed using principal component-linear discriminant analysis (PC-LDA). Two responders with tumor regression were predicted as ‘hot' phenotype while the non-responding patients (remaining 7) were classified as cold phenotype; suggesting that RCM 'hot' phenotype correlates with better treatment response. Thus, we demonstrate the potential utility of noninvasive RCM imaging in identifying ‘hot' and ‘cold' tumor phenotypes directly in patients. Citation Format: Aditi Sahu, Melissa Gill, Miguel Cordova, Anthony Santella, Kivanc Kose, Teguru Tembo, Anabel Alfonso, Pratik Chandrani, Christi Fox, Salvador Gonzalez, Nicholas Kurtansky, Melissa Pulitzer, William Phillips, Madison Li, Kimeil King, Stephen Dusza, Shuaitong Liu, Ning Yang, Haaris Jilani, Paras Mehta, Ashfaq Marghoob, Allan Halpern, Anthony Rossi, Liang Deng, Chih-Shan Jason Chen, Milind Rajadhyaksha. Dynamic imaging of tumor-immune microenvironment (TiME) and microvasculature identifies ‘hot' and ‘cold' tumor phenotypes in vivo in patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2814.

Bowen's disease (BD) is a relatively rare early-stage squamous cell carcinoma in situ, most commonly affecting the middle-aged and elderly, and occurring on the skin or mucous membranes of various parts of the body. Its onset is concealed, the course of the disease is chronic, and some patients have malignant tumors outside the skin; therefore, it is necessary to diagnose and evaluate the disease at an early stage. This study aimed to investigate the application of reflectance confocal microscopy (RCM) in the diagnosis of BD. We performed RCM imaging on the lesion site and underwent skin biopsy for histological diagnosis of 92 patients initially diagnosed with BD in clinic. A retrospective analysis of the RCM result as well as the histological examination revealed that after analyzing RCM images, out of 92 biopsy lesions, 61 were diagnosed with BD, of which 54 were consistent with RCM diagnosis. Among the 59 cases diagnosed with BD by RCM, 54 cases were consistent with the histological diagnosis. Afterwards, we analyzed the RCM characteristics in patients with BD verified by biopsy, and compared the RCM images of two different lesions, classic Bowen's disease and pigmented Bowen's disease, and further summarized the key points of BD under RCM. Finally, we focused on the differential characteristics between BD and other skin diseases in RCM. RCM is of great value in the diagnosis of BD. RESEARCH HIGHLIGHTS: A retrospective study of RCM and histological diagnosis in patients with clinical diagnosis of BD. Analyze the RCM characteristics of skin lesions verified by biopsy. RCM is of great value in the diagnosis and differentiation of BD.

Both Wood's lamp and reflective confidential laser scanning microcopy are helpful for the diagnosis and treatment of vitiligo. However, there is few research that contains large samples and consistent observations. To analyze the characteristics of Wood's lamp images and reflectance confocal microscopy (RCM) images of vitiligo lesions and to evaluate their significance in vitiligo staging. We analyzed the characteristics of RCM images, Wood's lamp images, the vitiligo disease activity (VIDA) score, and clinical features to guide vitiligo staging and treatment. The expert consensus based on the clinical features, VIDA score, Wood's lamp findings, and isomorphic response was consistent with the Wood's lamp findings (χ2 = 3.63, p > 0.05) and RCM findings (χ2 = 3.60, p > 0.05) in diagnosing vitiligo and assessing the disease stage. There was a correlation between the three lesion grades based on the Wood's lamp findings and the stage of vitiligo (p < 0.01). Lesions that appeared porcelain white under the Wood's lamp were in the slowly progressive stage; lesions that appeared gray-white or trichromatic under the Wood's lamp were in the rapidly progressive stage; lesions with clear borders under the Wood's lamp needed further analysis by RCM for the stage to be determined; lesions with blurred borders under the Wood's lamp were in the rapidly progressive stage; lesions that were visible under the naked eye and under the Wood's lamp were in the rapidly progressive stage. The study demonstrates a reliable correlation between the findings of RCM (a sophisticated expensive tool) and Wood's lamp examination (a simple, readily available, inexpensive tool) in the assessment of the disease activity of vitiligo lesions.

Nevus phenotype is a marker of melanoma risk. Invivo prediction of microscopic pattern is needed to more precisely classify nevi. To identify dermoscopic and clinical predictors of microscopic patterns of typical nevi. We used reflectance confocal microscopy (RCM) to classify microscopic patterns of nevi. We prospectively accrued adults presenting for periodic skin screening and imaged, with dermoscopy and RCM, 3 randomly selected nevi from the upper and lower back and lower extremity. RCM patterns were classified into ring, clod, meshwork, and composite types. Logistic regression was used to identify best predictors of RCM pattern. The study included 310 nevi from 112 participants (mean age 44years; 51 women). Dermoscopic reticular pattern correlated most frequently (59.9%) with RCM ring pattern, dermoscopic globular with RCM composite (56.6%) and RCM clod (35.9%), dermoscopic complex with RCM composite (76.3%), and dermoscopic homogenous with RCM clod (50.8%). Integrating dermoscopic pattern with contour, diameter, color, and anatomic location of nevi improved prediction of microscopic patterns beyond dermoscopy alone. The dermoscopic clinical regression model correctly classified lesions to RCM ring versus RCM clod in 90% and to RCM ring versus RCM composite patterns in 81%. The study was restricted to adults, back and lower extremities, and typical nevi. Integrating dermoscopic patterns with clinical attributes may improve prediction of microscopic patterns of nevi.

Reflectance confocal microscopy (RCM) has been used for the evaluation of several inflammatory skin conditions, including skin discoid lupus erythematosus (DLE), and has been correlated with conventional histopathology (HP). However, RCM is not being widely used in trichology. Few reports and just preliminary data suggest the use of RCM as a complementary tool in alopecias. To correlate the major RCM features of scalp DLE with trichoscopy and HP findings of biopsy specimens obtained from the same lesions. This is an observational, analytical, and cross-sectional study involving 12 patients with a clinically established diagnosis of scalp DLE. Patients underwent global clinical photograph, trichoscopy, and RCM examination in the same site followed by two 4-mm punch biopsy specimens for HP analysis. Inter-methods agreement among RCM imaging, trichoscopy, and horizontal histopathology sections (HHS) were calculated using Cohen Kappa (k) statistics. Statistical analysis of the agreement between RCM and HP features disclosed an overall agreement similar to skin DLE. Seven of the eleven features evaluated had agreement superior to 75%. We also evaluated RCM features associated with three of their corresponding trichoscopic findings for further investigation of their agreement with HP. Statistical analysis showed an enhancement with agreement of 86% when the non-invasive techniques are used together. Consistent correlation between RCM and HP observed in our study supports the reliability of RCM in the diagnosis of scalp DLE. RCM may be considered a promising tool for scalp DLE microscopic evaluation and presents similar RCM features to DLE in other body sites. By associating clinical, trichoscopic and RCM evaluation, dermatologists will have a non-invasive arsenal for the assessment of hair and scalp disorders, benefiting patients.

Scabies is an infectious skin disease caused by scabies mites parasitic on the skin. Scabies mites often parasitize on thin and soft parts of the skin, such as finger seams and their sides, wrist curve, elbow fossa, armpit, periumbilical, waist, lower abdomen, genitalia, groin, and the inner side of the upper thigh,1 and they tend to occur in families or crowded people.2 On the premise of having typical skin lesions and medical history, the diagnostic rate of scabies is still high. However, some patients have atypical skin lesions and eczema like changes due to repeated scratching and irritation caused by severe itching. In addition, some patients have a relatively long medical history and no social history, which makes it difficult to diagnose scabies. As a result, scabies can be misdiagnosed clinically and delay the patient's condition. Generally, scabies are easily misdiagnosed as skin pruritus eczema and prurigo, etc. In the past, we mainly used direct microscopic examination and histopathological biopsy to diagnose scabies. Direct microscopic examination or biopsy to find scabies mites, eggs, or fecal balls is the gold standard for the diagnosis of scabies. However, the positive rate of clinical smear microscopy is low, and the operation time is long, which can cause discomfort to patients and cannot be well coordinated. Histopathological biopsy is an invasive examination, which is difficult for many patients to accept. Therefore, there are many limitations in the diagnosis of scabies by traditional auxiliary means. Reflective confocal microscope (skin CT) is a new skin imaging diagnostic technology. It has the characteristics of noninvasive, in vivo, real-time acquisition of skin lesions.3 It can scan the same skin lesions at multiple levels and times to improve the diagnostic rate. It has been widely used in the diagnosis of various skin diseases. However, there are few reports on the image characteristics of scabies under the reflective confocal microscope. Recently, in clinical work, we performed skin computed tomography (CT) examination on patients diagnosed with scabies. By collecting skin CT images of these patients, we summarized the characteristics of reflective confocal microscope images of scabies, and now we share them with you. The reflective confocal microscope features of scabies mainly include the following points: 1. sponge edema in the acanthous layer, formation of focal blisters in the epidermis, and low refractive liquid dark areas (Figure 1A,B). 2. The tunnel structure can be seen in the upper part of the cuticle and acanthus layer. Scanning layer by layer along the tunnel shows that the structure of scabies (scabies mite) with medium and low refraction can be seen (Figure 2A,B). The morphology of scabies mites is similar to that observed by direct microscopy (Figure 2C), forming a nest-like structure. Two pairs of forefoot of some scabies mites can be clearly seen. 3. Middle low refraction round or oval scabies egg structure can be seen in the middle upper part of acanthous layer, with clear boundary (Figure 3A,B). 4. In the back of scabies mite, there are many regular round or oval high refraction dung ball structures at the superficial layer of the epidermis, some of which are lumpy (Figure 4A,B). In these microscopic features, it is highly specific to find scabies mites, scabies eggs, or dung ball structures for the diagnosis of scabies, and scabies can be diagnosed when one of the three is found under skin CT. Through our observation, dung ball is the most common feature of reflex confocal microscope in scabies, and its sensitivity and specificity are high. It is of great significance to diagnose scabies. Through the above sharing, we believe that we have a clear understanding of the typical skin CT features of scabies, and we hope that the reflective confocal microscope can be used as an important auxiliary examination method for scabies diagnosis in the future to help clinicians better diagnose and differentiate scabies.

Histological examination is the gold standard for actinic keratosis diagnosis; however, it is not always a feasible approach. Reflectance confocal microscopy (RCM) is a non-invasive technique that may be an alternative for monitoring actinic keratoses treatment response. Topical 5-fluorouracil is indicated for actinic keratosis multiple lesions and for field cancerization treatment. To assess the RCM accuracy, sensibility and specificity for actinic keratosis, considering as a gold standard the histopathological examination; as well as to evaluate the efficacy of 5% 5-fluorouracil treatment. This is a prospective study in actinic keratosis patients between August 2014 and November 2015. RCM analyses were performed in one randomly selected actinic keratosis lesion of the upper limbs by two independent observers before and after 5% 5-fluorouracil treatment. At the end of treatment and with clinical bleaching of treated lesions, histological examination was performed by two pathologists. A total of 50 lesions were enroled, and 40 lesions presented complete clinical bleaching after treatment and were included in the final analysis. Accuracy, sensibility and specificity means among observers were 83.8%, 84.6% and 83.3%, respectively. After 5-fluorouracil treatment, actinic keratosis was diagnosed in 45.0% (observer 1) and 32.5% (observer 2) of subjects according to RCM and in 32.5% of subjects according to histological examination. Considering RCM observers diagnosis, the concordance was substantial (k 0.637, P<0.001). 5-fluorouracil led to a reduction in 55.0%-67.5% of actinic keratoses according to RCM analysis. This study allows to validate RCM as a non-invasive method capable of monitoring actinic keratosis therapeutic response to 5-fluorouracil, presenting efficacy comparable to histological examination. Additionally, the results suggest that 5-fluorouracil may be a satisfactory option for therapeutic control of this condition.

Background: Actinic keratosis (AK) is a common UV-induced intraepidermal neoplasm and a precursor to cutaneous squamous cell carcinoma (cSCC). Accurate, non-invasive assessment of AK severity is crucial for early intervention and risk stratification. Objective: To evaluate the relationship between clinical severity of AK, as defined by the Olsen grading scale, and predefined dermoscopic and reflectance confocal microscopy (RCM) features. Methods: This cross-sectional study enrolled 50 patients with clinically diagnosed AK at a tertiary dermatology center between April 2024 and July 2025. Each lesion was assessed clinically using the Olsen scale (grades 1-3), dermoscopically (five features scored 0-3; total score 0-15), and via RCM (five RCM parameters scored 0-3; total score 0-15). Statistical correlations between clinical grade and imaging features were analyzed using Pearson's χ2 test with effect size metrics. Results: Diffuse erythema (p < 0.001), micro-erosions (p = 0.002), strawberry pattern (p = 0.038), and scales (p = 0.012) correlated significantly with Olsen grade, whereas vessels (p = 0.566) did not. All five RCM parameters showed strong associations with clinical severity. Composite dermoscopic and RCM scores correlated with Olsen grade (both p < 0.001). Abnormal honeycomb pattern, parakeratosis, inflammation, and solar elastosis were the best RCM predictors of high dermoscopic severity (all p < 0.001); conversely, erosions, erythema, and scales were the strongest dermoscopic predictors of high RCM severity (all p < 0.001). Conclusions: This study demonstrates strong, statistically significant associations between clinical, dermoscopic, and confocal features of AK. This supports the integration of multimodal scoring into unified AK severity frameworks.