[MOCK MOLE: PRODUCING SYNTHETIC IMAGES THAT RECAPITULATE CONFOCAL PATTERNS OF MELANOCYTIC NEVI VIA DEEP-LEARNING MODELS].

INTRODUCTION: Melanocytic nevi present microscopic patterns, which differ in their associated melanoma risk, and can be non-invasively recognized under Reflectance Confocal Microscopy (RCM). AIMS: To train a Generative Adversarial Network (GAN) deep-learning model to produce synthetic images that recapitulate RCM patterns of nevi, enabling reliable classification by human readers and by a Convolutional Neural Network (CNN) computer model. METHODS: A dataset of RCM images of nevi, presenting a uniform pattern, were chosen and classified into one of three patterns - Meshwork, Ring or Clod. Images were used for training a GAN model, which in turn, produced synthetic images recapitulating RCM patterns of nevi. A random sample of synthetic images was classified by two independent human readers and by a CNN model. Human and computer-model classifications were compared. RESULTS: The training set for the GAN model included 1496 RCM images, including 977 images (65.3%) with Meshwork pattern, 261 (17.4%) with Ring and 258 (17.2%) with Clod pattern. The GAN model produced 6000 synthetic RCM-like images. Of these, 302 images were randomly chosen and classified by human readers, including 83 (27.5%) classified as Meshwork, 131 (43.4%) as Ring, and 88 (29.1%) as Clod pattern. Human inter-observer concordance in pattern classification was 91.7%, and human-to-CNN concordance was 87.7%. CONCLUSIONS: We demonstrate feasibility of producing synthetic images, which recapitulate RCM patterns of nevi and can be reproducibly recognized by human readers and by deep-learning models. Synthetic image datasets may allow teaching RCM patterns to novices, training of computer models, and data sharing between research centers.

Nevus cell aggregates massively occupying parenchyma of an external iliac lymph node: A case report and review of the literature.

We report a case of nevus cell aggregates (NCAs) in an external iliac lymph node from a patient with a compound congenital nevus in the corresponding drainage skin. Melanocytes in parenchyma were in band, nest-like or nodular fashion, and partly continuous with those in capsule and trabeculae. The largest nodule in parenchyma measured 6.5 mm. Melanocytes mostly exhibited benign appearance identical to cutaneous nevus. A few regions abundant in cells displayed atypical features, including increased nucleo-cytoplasmic ratio, small nucleoli, and occasional mitotic figures. Immunohistochemistry showed that melanocytes stained positive for p16, but negative for HMB-45 and nestin. Ki-67 labeling was less than 1% and reticulin mainly surrounded individual melanocytes. Besides, Vysis melanoma fluorescence in situ hybridization (FISH) plus another 2 probes targeting 9p21(CDKN2A) and 8q24(MYC) showed normal results. The patient is alive without malignant tumor after 52-month follow up. Our case provides a new evidence for the existence of intraparenchymal NCAs in deep lymph node and indicates that melanocytes with some atypical features can occur in nodal nevi. Nevus cells in parenchyma connected to those in capsule and trabeculae are a significant clue to distinguish nodal nevi from metastatic melanomas. Additionally, immunohistochemistry and FISH assay are useful in differential diagnosis.

A study of dermal melanophages in childhood nevi. Reassessing so-called "pigment incontinence".

In inflammatory dermatoses, dermal melanophages (MLP) are ascribed to "pigment incontinence," with melanin "dropping down" from the epidermis. Although this is analogous to the "dropping down" of melanocytic nevus cells (Abtropfung), MLP in ordinary nevi have not been systematically studied-so "pigment incontinence" may not apply to MLP in nevi. A total of 31 childhood nevi identified by pediatricians and family practitioners were evaluated for the distribution of MLP. We tested the hypothesis that a dermal origin of the melanin in MLP is more likely than dropping down from the epidermis. In our cohort, 90.3% (28/31) of childhood nevi had dermal MLP, a significantly higher frequency, compared to 31/60 ordinary adult nevi (P < 0.0001). Superficial dermis was the most common location (P < 0.001). However, only six specimens had MLP restricted to the superficial dermis, significantly less than predicted by the theory that melanin drops down from the epidermis (P < 0.00001). We also evaluated perivascular MLP, since nerves run together with vessels in neurovascular bundles (NVB), and it has been showed that precursors of melanocytes migrate from the neural crest to the skin as nerve sheath stem cells. Superficial NVB MLP correlated with deep NVB bundle MLP (P < 0.05), suggesting that NVB MLP represent "tombstones" for superficial and deep dermal nevus cells. Deep dermal, deep NVB, and deep periadnexal MLP may be valid biological criteria for diagnosis of congenital type (prenatal) nevi. Viewing prenatal nevi in children as a neurocristopathy fits a major principle of pediatric pathology: childhood diseases should be studied and understood based on what happens during tissue development.

Accuracy of tele-consultation on management decisions of lesions suspect for melanoma using reflectance confocal microscopy as a stand-alone diagnostic tool.

BACKGROUND: Diagnostic accuracy of reflectance confocal microscopy (RCM) as a stand-alone diagnostic tool for suspect skin lesions has not been extensively studied. OBJECTIVE: Primary aim was to measure experts' accuracy in RCM-based management decisions. Secondary aim was to identify melanoma-specific RCM features. METHODS: The study enrolled patients ≥18 years that underwent biopsy of skin lesions clinically suspected to be melanoma. One hundred lesions imaged by RCM were randomly selected from 439 lesions prospectively collected at four pigmented lesion clinics. The study data set included 23 melanomas, three basal cell and two squamous cell carcinomas, 11 indeterminate melanocytic lesions and 61 benign lesions including 50 nevi. Three expert RCM evaluators were blinded to clinical or dermoscopic images, and to the final histopathological diagnosis. Evaluators independently issued a binary RCM-based management decision, 'biopsy' vs. 'observation'; these decisions were scored against histopathological diagnosis, with 'biopsy' as the correct management decision for malignant and indeterminate lesions. A subset analysis of 23 melanomas and 50 nevi with unequivocal histopathological diagnosis was performed to identify melanoma-specific RCM features. RESULTS: Sensitivity, specificity and diagnostic accuracy were 74%, 67% and 70% for reader 1, 46%, 84% and 69% for reader 2, and 72%, 46% and 56% for reader 3, respectively. The overall kappa for management decisions was 0.34. Readers had unanimous agreement on management for 50 of the 100 lesions. Non-specific architecture, non-visible papillae, streaming of nuclei, coarse collagen fibres and abnormal vasculature showed a significant association with melanoma in the evaluation of at least two readers. CONCLUSIONS: Reflectance confocal microscopy tele-consultation of especially challenging lesions, based on image review without benefit of clinical or dermoscopy images, may be associated with limited diagnostic accuracy and interobserver agreement. Architectural and stromal criteria may emerge as potentially useful and reproducible criteria for melanoma diagnosis.

Computer Based Melanocytic and Nevus Image Enhancement and Segmentation.

Digital dermoscopy aids dermatologists in monitoring potentially cancerous skin lesions. Melanoma is the 5th common form of skin cancer that is rare but the most dangerous. Melanoma is curable if it is detected at an early stage. Automated segmentation of cancerous lesion from normal skin is the most critical yet tricky part in computerized lesion detection and classification. The effectiveness and accuracy of lesion classification are critically dependent on the quality of lesion segmentation. In this paper, we have proposed a novel approach that can automatically preprocess the image and then segment the lesion. The system filters unwanted artifacts including hairs, gel, bubbles, and specular reflection. A novel approach is presented using the concept of wavelets for detection and inpainting the hairs present in the cancer images. The contrast of lesion with the skin is enhanced using adaptive sigmoidal function that takes care of the localized intensity distribution within a given lesion's images. We then present a segmentation approach to precisely segment the lesion from the background. The proposed approach is tested on the European database of dermoscopic images. Results are compared with the competitors to demonstrate the superiority of the suggested approach.

Nuclear and cytoplasmic features in the diagnosis of banal nevi, Spitz nevi, and melanoma.

BACKGROUND: Many authors have described cytologic features in a variety of melanocytic lesions but, to our knowledge, a statistical analysis of sensitivity, specificity, and overall accuracy of these features alone or in combination has not been performed. OBJECTIVE: We sought to determine the diagnostic value of nuclear and cytoplasmic characteristics in the diagnosis of melanocytic lesions via multivariate statistical analysis. METHODS: This is a retrospective observational study conducted on 300 melanocytic lesions. We evaluated a series of distinctive features; subsequently a multivariate model was used to determine sensitivity and specificity. RESULTS: Major features that favor a diagnosis of melanoma include: pleomorphism with enlarged nuclei, mitotic figures, notching/corrugation of the nuclear envelope, and peppered moth nucleus. Features with intermediate value include: solid hyperchromasia, vesicular nucleus with single round nucleolus, and nuclear/cytoplasmic ratio greater than 4:1. LIMITATIONS: Limitations of this study include its retrospective nature, and the reliance on the original diagnostic classification of each neoplasm. CONCLUSION: Our data suggest that some nuclear alterations have greater value in the diagnosis of benign and malignant melanocytic lesions.

Precise Longitudinal Tracking of Microscopic Structures in Melanocytic Nevi Using Reflectance Confocal Microscopy: A Feasibility Study.

IMPORTANCE: Reflectance confocal microscopy (RCM), a cellular-level, in vivo imaging technique, may be potentially used for monitoring melanocytic neoplasms for microscopic stability vs changes over time. OBJECTIVE: To test feasibility of using RCM to track specific microscopic structures within nevi over 1 year. DESIGN, SETTING, AND PARTICIPANTS: This was an observational study, a review of prospectively acquired RCM images, performed at a tertiary academic medical center. Seventeen patients were enrolled from adult patients presenting to pigmented lesion clinic; from each participant, 3 confirmed benign nevi were randomly selected from the upper and lower back and from the lower extremity. EXPOSURES: Nevi underwent standardized RCM imaging at baseline and after 1 year. MAIN OUTCOMES AND MEASURES: We tested interobserver reproducibility in recognition of tissue anchors, RCM structures that can be identified at 2 time points. We used 2 tests to measure concordance between independent readers: (1) In the multiple choice matching test (n = 43 nevi), readers were shown a tissue anchor in a baseline RCM image (≤ 1 × 1-mm field-of-view) and asked to identify the same structure in 1 of 4 equally sized RCM images obtained from the same nevus at follow-up. (2) In the annotation test (n = 29 nevi), readers were shown a tissue anchor in a follow-up RCM image (≤ 1 × 1-mm field-of-view) and asked to annotate the corresponding location of this structure in the baseline RCM mosaic image (≤ 5 × 5-mm field-of-view) from the same nevus; good agreement was defined as annotations deviant by less than 10% of the mosaic's width. RESULTS: In total, 17 patients (mean age, 45 years [range, 28-70 years]; 10 [59%] were women) contributed a total of 51 nevi, of which 44 nevi (86%) were used for the study. Images from 7 nevi (14%) were suboptimal in quality. Tissue anchors were identified at both time points in all 44 nevi. Selected tissue anchors were located at a mean depth of 54.3 µm; the most commonly selected anchors (37 of 44 images [84.1%]) were dermal papillae. In the multiple choice matching test, compared with a reference reader, 2 readers correctly matched baseline to follow-up tissue anchors in 40 of 43 nevi (93%; P < .01) and 42 of 43 nevi (98%; P < .01), respectively. In the annotation test, there was good agreement between 2 readers in all 29 cases (100%); the mean deviation was 2% (range, 0%-7.5%). CONCLUSIONS AND RELEVANCE: Precise longitudinal tracking of microscopic structures in melanocytic nevi using RCM is feasible.

Atypical histopathologic features in a melanocytic nevus after cryotherapy and pregnancy.

Melanocytic nevi can undergo clinical and histopathologic changes during pregnancy, as well as after various forms of surgical and nonsurgical trauma. We report the case of a 9-month postpartum 29-year-old female who presented to her dermatologist with a clinically worrisome nevus. This nevus had been treated with liquid nitrogen by her primary care physician 6 months prior to presentation. Histopathologic evaluation revealed a crowded proliferation of atypical melanocytes at the dermal-epidermal junction overlying a scar. The dermal component contained scattered mitotic figures. A combined MART-1, tyrosinase and Ki-67 immunohistochemical study showed foci of increased melanocytic proliferation. These atypical features were interpreted as associated with both the prior cryotherapy, as well as her recent pregnancy. Knowledge of the clinical context in evaluating difficult melanocytic lesions is essential.

Detecting ultrasonographic hollowness in small choroidal melanocytic tumors using 10 MHz and 20 MHz ultrasonography: a comparative study.

BACKGROUND: The purpose of this work was to compare the detection of ultrasonographic hollowness (UH), as a risk sign for evolution from small choroidal melanocytic tumors (SCMT) to uveal melanoma (UM), between conventional ultrasonography (standardized 8 MHz ultrasonography and B-mode 10 MHz ultrasonography) and high-resolution 20 MHz ultrasonography. METHODS: Fifty SCMTs from 50 eyes were included in this work. In all cases, ultrasonographic studies were performed using: 8 MHz standardized A-mode, 10 MHz B-mode, and posterior pole 20 MHz B-mode. Comparison between the presence and the absence of UH were carried out between the ultrasonographic images. RESULTS: There were no statistically significant differences between the SCMT dimensions obtained using the 8-10 and 20 MHz techniques. UH was detected in 12 and 20 cases by means of ten and 20 MHz probes respectively. The difference between these proportions was statistically different from zero (McNemar test, p-value = 0.008). Cases without UH by 20 MHz have lower height values than cases with UH. However, these differences were not found by 10 MHz ultrasonography. By receiver operating characteristic (ROC) study, specificity was better by 20 MHz than 10 MHz ultrasonography when the value of tumor height as marker for UH was studied. CONCLUSIONS: UH is easier to detect by 20 MHz than by 10 MHz ultrasonography. This ultrasonographic sign appears to be correlated with the height of the tumor. Thus, we believe UH estimation by 20 MHz ultrasonography could be used as a significant predictive factor for SCMT growth.

Total dermoscopy score calculation using quantitative measurements in digital dermoscopy.

The main contributions of this paper are an automated approach for applying the ABCDE rules in a digital dermoscopy platform with fixed settings and a new registration method specially designed for aligning and comparing follow-up digital dermoscopy images in order to evaluate the evolution over time parameter E. Experimental evaluations of the registration method are reported for image pairs acquired during follow-up examinations.

Melanocytic differentiation is present in a significant proportion of nonpigmented diffuse neurofibromas: a potential diagnostic pitfall.

Whereas the pigmented (melanotic) variant of diffuse neurofibroma (DNF) with positivity for melanocytic markers is well recognized, expression of melanocytic markers in nonpigmented DNF has not been systematically studied. We analyzed 28 unselected consecutive DNFs for expression of melanocytic markers, including melan A, microphthalmia transcription factor (MITF), and HMB-45 antigen. For comparison, we also analyzed 40 localized skin neurofibromas and 7 intraneural neurofibromas. One case of nonpigmented DNF was analyzed by electron microscopy. Of the 28 DNFs studied by immunohistochemistry, 3 were pigmented and 25 nonpigmented. The 3 pigmented DNFs and 9 of 25 (36%) nonpigmented DNFs expressed melan A, MITF, and HMB-45 antigen. These markers were expressed either focally or more diffusely, typically in a minority of the lesional cells, and usually both in the dermal and subcutaneous portion of the DNF. Melan A was expressed in the largest number of the lesional cells (up to 50%), whereas only a small fraction of the melan A-positive cells (from 5% to 10% in most cases) also expressed HMB-45 antigen. None of the 47 non-DNFs expressed these markers. Ultrastructurally, melanosomes were present in some cells in nonpigmented DNF that expressed the melanocytic markers. Twenty-three of 28 (82%) DNFs, including 10 of 12 (83%) DNFs with melanocytic differentiation, were associated with neurofibromatosis type 1. Expression of melanocytic markers, including melan A, HMB-45 antigen, and MITF in DNF is a potential pitfall in differential diagnosis with melanocytic lesions that may clinically or histopathologically resemble DNF, in particular congenital melanocytic nevus with neurotization and neurofibroma-like melanoma.

Immunohistochemical and ultrastructural features of congenital melanocytic naevus cells support a stem-cell phenotype.

BACKGROUND: Multiple congenital melanocytic naevi (CMN) in one individual are caused by somatic mosaicism for NRAS mutations; however, the lineage of the mutated cells remains uncertain. OBJECTIVES: To test the hypothesis that CMN may be derived from cutaneous stem cells. METHODS: Sixty-six CMN samples from 44 patients were stained for immunohistochemical (IHC) markers of melanocytic differentiation (TYR, TRP1, TRP2, LEF1, MITF, cKit), pluripotency (nestin, fascin, CD133, CD20, CD34), monocyte/macrophage lineage (CD68, CD163, CD14), proliferation (Ki67) and MTOR/Wnt-signalling pathway activation (pS6, ß-catenin). Semiquantitative scoring compared samples with naevus cell nesting (group 1) with those with only diffuse dermal infiltration (group 2). Transmission electron microscopy (TEM) was performed on 10 samples. RESULTS: A normal melanocyte population was seen overlying many dermal CMN. Group 1 samples were significantly more likely to express melanocytic differentiation markers than group 2, and expression decreased significantly with depth. Expression of these markers was correlated with each other, and with nestin and fascin. CD20 staining was positive in a substantial proportion and was stronger superficially. Expression of ß-catenin and pS6 was almost universal. Some samples expressed monocyte/macrophage markers. TEM revealed variable naevus cell morphology, striking macromelanosomes, double cilia and microvilli. CONCLUSIONS: Congenital melanocytic naevi development frequently coexists with normal overlying melanocyte development, leading us to hypothesize that in these cases CMN are likely to develop from a cell present in the skin independent of, or remaining after, normal melanocytic migration. IHC and TEM findings are compatible with CMN cells being of cutaneous stem-cell origin, capable of some degree of melanocytic differentiation superficially.

The role of various immersion liquids at digital dermoscopy in structural analysis.

BACKGROUND: Dermoscopy is a useful method that allows dermal and epidermal structures to be easily analysed non-invasively. AIM: In this study, immersion oil, which is widely used in dermoscopy, and ultrasound gel, which is less preferred, are evaluated comparatively in terms of displaying structural parameters and number of air bubbles in the image. METHODS: A total of 71 nevomelanocytic or non-melanocytic pigmented lesions were taken up for this study. Structural characteristics of the obtained images were assessed by an experienced observer who scored the images in terms of color, pigment network, globule, vascular structure, number of air bubbles and other pigmentation parameters. RESULTS: In the images obtained through immersion oil or ultrasound gel from all of the lesions, no statistical difference was found between the average values of air bubbles and in the evaluation of structural components (t=1.09, P=0.2). In the identification of pigment network in melanocytic lesions, immersion oil was observed to be more appropriate than ultrasound gel (t=0.01, P=0.02). CONCLUSIONS: Ultrasound gel may be preferred in the assessment of mucosa and nail bed lesions. Ultrasound gel is a good alternative compared to immersion oil in pigmented skin lesions as it is cheap and easily removable.

Correspondence between dermoscopic features and epidermal structures revealed by scanning electron microscope.

It is already known that some typical dermoscopic patterns seen in melanocytic nevi on the sole have their own favorite site. In the weight-bearing area, melanocytic nevi with a parallel furrow pattern were preferentially observed. Those with a lattice-like pattern were observed in the arch area, whereas those with a crista reticulated pattern were seen in the border area. To investigate the relationship between the distribution of the dermoscopic patterns seen in plantar melanocytic nevi and the 3-D structures of the epidermis, the basal surfaces of the plantar epidermis from 14 skin lesions were observed by scanning electron microscopy (SEM). Our SEM observations revealed that transverse ridges formed a couple of parallel lamellae on the crista profunda limitans (limiting ridges). Between the limiting ridges and the crista profunda intermedia (intermediate ridges), the transverse ridges had different shapes according to the anatomical location of the sole. From these results, it was suggested that the characteristic dermoscopic patterns seen in acquired and junctional melanocytic nevi on the sole simulate the arrangement of transverse ridges.

Reflectance confocal microscopy and features of melanocytic lesions: an internet-based study of the reproducibility of terminology.

OBJECTIVE: To test the interobserver and intraobserver reproducibility of the standard terminology for description and diagnosis of melanocytic lesions in in vivo confocal microscopy. DESIGN: A dedicated Web platform was developed to train the participants and to allow independent distant evaluations of confocal images via the Internet. SETTING: Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy. PARTICIPANTS: The study population was composed of 15 melanomas, 30 nevi, and 5 Spitz/Reed nevi. Six expert centers were invited to participate at the study. Intervention Evaluation of 36 features in 345 confocal microscopic images from melanocytic lesions. MAIN OUTCOME MEASURE: Interobserved and intraobserved agreement, by calculating the Cohen kappa statistics measure for each descriptor. RESULTS: High overall levels of reproducibility were shown for most of the evaluated features. In both the training and test sets there was a parallel trend of decreasing kappa values as deeper anatomic skin levels were evaluated. All of the features, except 1, used for melanoma diagnosis, including roundish pagetoid cells, nonedged papillae, atypical cells in basal layer, cerebriform clusters, and nucleated cells infiltrating dermal papillae, showed high overall levels of reproducibility. However, less-than-ideal reproducibility was obtained for some descriptors, such as grainy appearance of the epidermis, junctional thickening, mild atypia in basal layer, plump bright cells, small bright cells, and reticulated fibers in the dermis. Conclusion The standard consensus confocal terminology useful for the evaluation of melanocytic lesions was reproducibly recognized by independent observers.

In vivo confocal microscopic and histopathologic correlations of dermoscopic features in 202 melanocytic lesions.

OBJECTIVES: To identify in vivo microscopic substrates of the dermoscopic patterns of melanocytic lesions and to correlate them with histopathologic features. DESIGN: Before excision, lesion areas that showed characteristic dermoscopic patterns were imaged by dermoscopy and confocal microscopy and directly correlated with histopathologic features. SETTING: Departments of Dermatology of the University of Modena and Reggio Emilia and Hospital Clínico of Barcelona, between July 2006 and March 2007. Patients Patients with 202 melanocytic lesions, corresponding to 76 melanomas, 114 nevi, and 12 Spitz or Reed nevi. MAIN OUTCOME MEASURES: Correlation of dermoscopic patterns in melanocytic lesions with confocal microscopic findings and conventional histopathologic findings. RESULTS: Characteristic architectural and cytologic substrates were identified in vivo with the use of confocal microscopy and correlated with histopathologic features. Pigment network atypia was evidenced through confocal microscopy as a disarrangement of dermoepidermal junction architecture and cellular atypia. Pigmented globules consisted of cell clusters, corresponding to melanocytic nests identified on histopathologic analysis. Black dots correlated with intraepidermal reflective spots or with large pagetoid cells in nevi and melanoma, respectively. Blue structures usually consisted of numerous pleomorphic cells, corresponding to malignant melanocytes and inflammatory cells in melanomas, whereas plump bright cells, corresponding to melanophages on histopathologic analysis, characterized benign lesions. Within regression, a retiform distribution of collagen fibers, which sometimes intermingled with melanophages and rarely with nucleated cells, was observable. CONCLUSIONS: The knowledge of the cytologic and architectural aspects of the different dermoscopic patterns, as they appear by in vivo confocal microscopy, may guide the user to the identification of specific substrates in melanocytic lesions and consequently the interpretation of the dermoscopic features.

Clinical, histopathological and ultrastructural characteristics of naevus depigmentosus.

BACKGROUND: Naevus depigmentosus (ND) is a congenital, nonfamilial, well-circumscribed, uniformly hypopigmented macule, the relative size and distribution of which is stable throughout life. The aetiopathogenesis of ND is not yet fully understood, and reports about the clinical and histopathological characteristics of ND are few. OBJECTIVE: To investigate the clinical and histopathological characteristics of ND, and to make it easier to diagnose ND clinically. METHODS: A clinical survey on 38 patients with ND was performed according to the diagnostic criteria proposed by Coupe. Wood's lamp examination was used to distinguish the different appearance of ND and vitiligo. Skin-biopsy specimens were stained with haematoxylin and eosin, silver, antibodies to S-100 protein, tyrosinase-related protein-1 and tyrosinase, then used for ultrastructural study. Melanocytes were also cultured. RESULTS: Leucoderma was present at birth in 13 patients (34.2%), and appeared during the first 3 years of life in 15 patients. The trunk was the most commonly affected site, and the lesions usually had serrated, irregular borders. Under Wood's lamp, lesions had an off-white accentuation without fluorescence. Immunohistochemistry showed that the melanin content of ND lesions was decreased compared with perilesional normal skin, but there was no change in the number of melanocytes. Ultrastructural study showed that some aggregated melanosomes were present in the affected keratinocytes. CONCLUSION: As a result of the above findings, we suggest changes to Coupe's criteria for ND.