Junctional Melanocytic Nevi Research Articles

Application of fluorescence in situ hybridization in distinguishing acral melanoma in situ from acral junctional melanocytic nevus on the volar skin in Japanese patients.

Four-colored fluorescence in situ hybridization (FISH) is an ancillary diagnostic tool for melanoma. However, most studies that have investigated the usefulness of FISH primarily focused on advanced melanomas. The aim of the current study was to evaluate the effectiveness of FISH in distinguishing acral melanoma (AM) in situ from benign acral junctional nevus (AJN), two types of lesions that are difficult to differentiate via traditional clinical means. The authors investigated the usefulness of FISH in 91 acral melanocytic lesions, including 50 lesions with diagnostic discrepancies between dermoscopic and pathologic approaches or difficulty diagnosing between AM in situ and AJN, on the volar skin of Japanese patients. The authors classified the lesions based on the diagnosis of dermatologists and pathologists into four groups: (I) lesions with a unanimous diagnosis by dermatologists and pathologists as AM in situ or AJN (n=41); (II) lesions with a unanimous diagnosis by dermatologists only as AM in situ or AJN (n=21); (III) lesions with a unanimous diagnosis by pathologists only as AM in situ or AJN (n=15); and (IV) all other lesions (n=14). The dermatologists diagnosed the lesions by clinical and dermoscopic photographs alone, while the pathologists diagnosed the lesions by microscopy of hematoxylin and eosin-stained slides alone. In group I (AM in situ [n=20] and AJN [n=21]), four-colored FISH demonstrated 90% sensitivity and 81% specificity in distinguishing AM in situ from AJN. There was a significant correlation between the FISH results and the unanimous diagnoses by pathologists alone (p=0.03) in group III. However, FISH results were not significantly correlated with the unanimous diagnoses by dermatologists alone (p=0.33) in group II. In conclusion, the four-colored FISH probe kit was useful in distinguishing between AM in situ and AJN and may be an ancillary method when pathologists who are not experts of dermatopathology diagnose melanocytic lesions.

Histologic Screening of Malignant Melanoma, Spitz, Dermal and Junctional Melanocytic Nevi Using a Deep Learning Model.

The integration of an artificial intelligence tool into pathologists' workflow may lead to a more accurate and timely diagnosis of melanocytic lesions, directly patient care. The objective of this study was to create and evaluate the performance of such a model in achieving clinical-grade diagnoses of Spitz nevi, dermal and junctional melanocytic nevi, and melanomas. We created a beginner-level training environment by teaching our algorithm to perform cytologic inferences on 136,216 manually annotated tiles of hematoxylin and eosin-stained slides consisting of unequivocal melanocytic nevi, Spitz nevi, and invasive melanoma cases. We sequentially trained and tested our network to provide a final diagnosis-classification on 39 cases in total. Positive predictive value (precision) and sensitivity (recall) were used to measure our performance. The tile-classification algorithm predicted the 136,216 irrelevant, melanoma, melanocytic nevi, and Spitz nevi tiles at sensitivities of 96%, 93%, 94% and 73%, respectively. The final trained model was able to correctly classify and predict the correct diagnosis in 85.7% of unseen cases (n = 28), reporting at or near screening-level performances for precision and recall of melanoma (76.2%, 100.0%), melanocytic nevi (100.0%, 75.0%), and Spitz nevi (100.0%, 75.0%). Our pilot study proves that convolutional networks trained on cellular morphology to classify melanocytic proliferations can be used as a powerful tool to assist pathologists in screening for melanoma versus other benign lesions.

ORAL JUNCTIONAL MELANOCYTIC NEVUS ASSOCIATED WITH LENTIGINOUS HYPERPLASIA: A CASE REPORT IN A PEDIATRIC PATIENT

Oral melanocytic nevi (OMNs) are uncommon benign melanocytic proliferations. Clinically, OMNs are small, well-circumscribed, flat lesions, but not uncommonly appear as slightly raised papules. They can be brown, bluish-gray, or almost black, and occasionally non- pigmented. Regarding the OMN etiology and pathogenesis, most studies have focused on its cutaneous counterpart. We present a case of OMN in a pediatric patient. A 4-year-old male was referred presenting a dark macule with regular borders, measuring 6 mm in greater diameter, located on the right retromolar pad, with a time of evolution of 15 days. The clinical diagnoses were melanotic macule and OMN. After excisional biopsy, the microscopic examination revealed junctional melanocytic nevus with lentiginous hyperplasia containing focal melanocytic atypia. After 4 months of follow-up, there is no recurrence or alteration. Thus, lentiginous junctional melanocytic proliferation with focal atypia may be observed in OMN, which should be interpreted with caution, especially in pediatric patients. Oral melanocytic nevi (OMNs) are uncommon benign melanocytic proliferations. Clinically, OMNs are small, well-circumscribed, flat lesions, but not uncommonly appear as slightly raised papules. They can be brown, bluish-gray, or almost black, and occasionally non- pigmented. Regarding the OMN etiology and pathogenesis, most studies have focused on its cutaneous counterpart. We present a case of OMN in a pediatric patient. A 4-year-old male was referred presenting a dark macule with regular borders, measuring 6 mm in greater diameter, located on the right retromolar pad, with a time of evolution of 15 days. The clinical diagnoses were melanotic macule and OMN. After excisional biopsy, the microscopic examination revealed junctional melanocytic nevus with lentiginous hyperplasia containing focal melanocytic atypia. After 4 months of follow-up, there is no recurrence or alteration. Thus, lentiginous junctional melanocytic proliferation with focal atypia may be observed in OMN, which should be interpreted with caution, especially in pediatric patients.

Carbon dioxide ablative laser treatment of acquired junctional melanocytic nevi.

Junctional melanocytic nevi are common. Furthermore, surgical treatment of these nevi can be challenging due to scar formation. The study aims to detect the efficacy and safety of the CO2 fractional laser for treating acquired junctional melanocytic nevi and usefulness of dermatoscopy for the monitoring of the nevus. We conducted a retrospective review of 618 patients with 1545 facial junctional melanocytic nevi. CO2 fractional laser was applied to 2-month intervals until complete clearance was reached. The effect of the therapy was monitored by clinical and dermatoscopy. The Global Assessment Scale (GAS) scores were used to assess the results. 1320 nevi (85%) were treated in just one session. In addition, 120 (8%) and 75 (5%) required second and third sessions, respectively. Only thirty nevi (2%) need more than three sessions. Consequently, at the end of one-year follow-up, patients' (97%) and physicians' (95%) GAS scores were rated as excellent and good, respectively. Moreover, hyper/hypopigmentation, fibrosis, dimples, erythema, and scars were observed as side effects at the 1-year follow-up. CO2 laser is effective in completely removing small acquired junctional melanocytic nevus. Furthermore, dermatoscopy appears to be helpful for monitorization of the nevi in the follow-up period.

Is Spontaneous Disappearance of Nevus Depigmentosus Possible?

Dear Editor: Nevus depigmentosus (ND) is characterized by a congenital hypopigmented macule or patch. The pathophysiology of ND is poorly understood, but likely associated with a functional defect in melanosome transfer from melanocytes to keratinocytes1. ND is known to remain generally stable in size and distribution throughout life1. Herein, we describe a case of a 6-year-old boy whose ND disappeared, suggesting the possibility of spontaneous resolution of ND. A 10-month-old male was brought to our clinic because of whitish patches on his right leg that had been present since his birth. Physical examination revealed hypopigmented patches on the medial side of right thigh (Fig. 1a). A diffuse bluish patch that was suspected to be an aberrant Mongolian spot surrounded the hypopigmented areas. A 2-mm punch biopsy of the hypopigmented patches and adjacent perilesional normal skin at 1 cm from margin was performed. There were no remarkable findings on H&E staining (Fig. 2a). Fontana-Masson staining showed decreased epidermal pigmentation in the lesional skin compared to the perilesional normal skin (Fig. 2b). There was no difference in the number of NKI/beteb positive melanocytes between the lesional and perilesional normal skin (Fig. 2c). These findings were consistent with ND. The patient did not receive any treatment and was lost to follow-up until his recent revisit 6 years later. At that time, he returned with a facial mobiliform eruption, accompanied by fever and conjunctival injection, and was diagnosed with erythema infectiosum. Interestingly, during physical examination, it was noted that the previous ND and the surrounding aberrant Mongolian spot had completely disappeared (Fig. 1b). The patient's parents did not recall the time of the ND disappearance. Fig. 1 Spontaneous disappearance of hypopigmented macules and patches. (a) A 10-month-old male presented with hypopigmented macules and patches on his right thigh in linear configuration since birth. A diffuse bluish patch that was suspected to be an aberrant ... Fig. 2 Histological findings. (a) There were no remarkable findings on H&E staining. (b) Fontana-Masson staining showed decreased epidermal pigmentation in the lesional skin compared to the perilesional normal skin. (c) There was no difference in the ... Spontaneous resolution of ND has never been reported. However, it should be noted that there has been no epidemiological study regarding the fate of ND. Moreover, there have been several reports suggesting the possibility that the functional defect of the melanocytes in ND is reversible2,3. Bardazzi et al.2 described the development of lentigines within ND after narrow band ultraviolet B exposure. They suggested the possibility of partial activation of melanosome transfer, resulting in overproduction of melanin within ND. Oiso et al.3 reported a case of acquired junctional melanocytic nevus development in ND. These cases suggest that melanocytes in ND could transform from a functionally defective stage to an active stage or shift to other forms such as nevus cells. Interestingly, in our case, the ND and Mongolian spots were coexistent at the initial visit and both had disappeared at the next visit. The possible relationship between Mongolian spots and spontaneous regression of ND could be suspected. There was no confirmative diagnosis of ND. It is important to consider the other hypopigmenting conditions, such as postinflammatory hypopigmentation or hypomelanosis of Ito4. Because the lesion was present from birth and he did not have any history of inflammation on the hypopigmented lesion, postinflammatory hypopigmentation could be differed from our case. Hypomelanosis of Ito consists of hypopigmented zones or spots with irregular borders, whorls, patches, or linear streaks with various patterns of distribution5. It follows the lines of Blaschko that represent a peculiar pattern of distribution. In addition, hypomelanosis of Ito usually encounter the extracutaneous manifestation. Reviewed in aspect of distribution of lesions and extracutaneous symptoms, we thought that hypomelanosis of Ito was less likely in our case. Therefore, considering the congenital hypopigmented macules, distribution, and other clinical manifestations, the hypopigmented macules and patches were most likely ND. In conclusion, our case suggests the possibility that ND could disappear. An epidemiological study of ND with long term follow up is further needed to know if ND could disappear, as in our case, or is persistent throughout life.

The important role of interdisciplinary collaboration in the management of a melanocytic skin lesion.

One of the most confounding characteristics, commonly seen in malignant, but even in benign melanocytic nevi, is represented by the regression phenomenon. The identification of regression, through dermoscopical observation, can be predictive of a tricky histopathological examination. Therefore, this feature should be an alert to a meticulous clinical, dermoscopical and histopathological correlation for correct analysis of melanocytic skin lesions. A 26-year-old man was referred to our department for a pigmented skin lesion localized on his trunk. It was clinically and dermoscopically diagnosed as atypical melanocytic nevus with central regression. After 1 year the lesion underwent considerable changes, leading to a nearly complete regression. The lesion was excised and, on the basis of clinical, dermoscopical and histopathological correlation, was interpreted as a junctional melanocytic nevus with regression. In our case the association of clinical, dermoscopical and histopathological experience, resulted an important and useful method, in order to proper interpret and correctly diagnose an atypical melanocytic skin lesion.

Prevalence of dermatological lesions in hospitalized children at the University College Hospital, Ibadan, Nigeria

Skin disorders constitute a significant proportion of consultations in children's clinics; however, there is a paucity of data on the prevalence of dermatological lesions in hospitalized children in Nigeria. This study determines the prevalence of dermatological lesions in hospitalized children. In this cross-sectional study, 402 children aged three months to twelve years admitted in the Pediatric wards of the University College Hospital, Ibadan, were enrolled over a six-month period. Examination of the skin and its appendages was done for each patient. Data on the socioeconomic status, hygiene, and health-related factors were also obtained using a structured questionnaire. Over 96% of the children had at least one identifiable skin lesion. The five leading skin lesions were post-inflammatory hyperpigmentation (49.5%), BCG scar (28.4%), Mongolian spots (27.1%), junctional melanocytic nevi (20.1%), and cafι-au-lait macules (18.4%). The leading infectious skin disease was pyoderma (13.4%), followed by tinea capitis (6.7%). Scarification marks (P=0.001), tinea capitis (P=0.014), plantar fissuring (P=0.001), and impetigo (P=0.016) were associated with low socioeconomic classes, while the presence of BCG scar (50.0%) was associated with the high socioeconomic class. This study shows that dermatologic lesions are common in hospitalized children. Identifying them will provide an opportunity for pediatricians to educate parents on the various causes as well as prevention of lesions.

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.

Angiomatoid Intradermal Melanocytic Nevus or Chimeric Nevus?: A Potential Diagnostic Pitfall

Angiomatoid Intradermal Melanocytic Nevus or Chimeric Nevus?: A Potential Diagnostic Pitfall

Tumor of the Follicular Infundibulum: An Epidermal Reaction Pattern?

Our recent experience indicates that the desmoplastic variant of tumor of the follicular infundibulum (TFI) is not, as previously believed, entirely uncommon. To clarify the defining clinical and microscopic features of TFI with special relevance to the histologic variants, we retrospectively reviewed cases with a histologic diagnosis of TFI between 1999 and 2008. Of the 74 cases retrieved, 53 TFI cases in 50 patients were identified with an incidence approximating 17 per 100,000. Clinically, TFI seems to be slightly more common in men (52% vs. 48%) and more common on the head and neck (around 77%) and presents as plaques (approximately 47%) and as multiple lesions (6%). Histologically, the majority showed classic features of a horizontal plate-like proliferation of large, bland-appearing, pale epithelial cells. Other features included an eosinophilic cuticle (70%), ductal differentiation (45%), cornoid lamellae (17%), and desmoplasia (11%). Of interest, approximately one fourth (25%) were associated with other cutaneous lesions, which included basal cell carcinoma, actinic keratosis, desmoplastic malignant melanoma, junctional melanocytic nevus, tricholemmoma, and epidermal inclusion cyst. In addition to expanding the constellation of the clinical and histopathologic findings, the increased association with other cutaneous lesions in the current study suggests that TFI may represent an epidermal reaction pattern.

Melanocytic proliferations associated with lichen sclerosus in adolescence

Lichen sclerosus is found in children with an estimated prevalence of at least 1 in 900. Pigmentation in lichen sclerosus is infrequent and melanocytic proliferations in lichen sclerosis are rare and difficult to interpret. In this report, we describe the case of a prepubertal girl presenting with a junctional melanocytic nevus of the labia minora superimposed by lichen sclerosus. The lesion was completely excised and free margins confirmed by histological examination. After a 3 months course of topical clobetasol treatment the girl remained asymptomatic. No local recurrence was notified with a follow-up time of 12 months.

Dermatoscopy in the diagnosis of tinea nigra

Tinea nigra is an asymptomatic superficial fungal infection caused by Phaeoannelomyces werneckii, generally affecting the skin of the palms and characterized by deeply pigmented macular non-scaly patches. These lesions are quite characteristic. However, they can be misdiagnosed as a malignant melanoma or a junctional melanocytic nevus and unnecessary biopsies may be performed. Thus, dermoscopy is a fast, useful, clinical adjunctive tool in differentiating tinea nigra from melanocytic lesion.

Histologic Spectrum of Melanocytic Nevi Removed from Patients > 60 Years of Age

The histology of melanocytic nevi removed from older patients often differs from that of nevi from younger adults. According to the literature, the most common nevus in older individuals is the intradermal nevus, and purely junctional nevi are rare and should alert the pathologist to a possible melanoma precursor. To evaluate the histologic features of melanocytic nevi removed from patients > 60 year of age. Biopsies of nevi (N=215) from 172 patients > 60 years (mean age 69+/-7 years) were examined retrospectively by three dermatopathologists, a consensus diagnosis was rendered, and the spectrum of histologic features was documented. Junctional melanocytic nevi were frequently diagnosed in older patients (21% of cases) and a lentiginous, often heavily pigmented growth pattern was common (12% of nevi). Severely atypical (dysplastic) changes were found in 6% of nevi removed from older patients. We conclude that benign junctional nevi are relatively common in older patients and that a lentiginous, heavily pigmented growth pattern, traditionally associated with younger individuals, is often seen in both junctional and compound nevi in this older age group. This pattern must be differentiated from dysplastic nevus and melanoma in situ, which they may clinically resemble.

Histologic Features of Melanocytic Nevi in Older Patients

The histology of melanocytic nevi in elderly patients often differs from nevi in younger adults. Our hypothesis was that nevi in patients3 60 yrs would demonstrate histologic patterns different from nevi in younger adults. Biopsies of nevi (n = 214) from 172 patients3 60 yrs (mean age 69 ± 7 yrs) were examined by three dermatopathologists and a consensus diagnosis was rendered. Control specimens (n = 82) from 58 patients 20–40 yrs (mean age 31 ± 5 yrs) were evaluated. Compound melanocytic nevi were commoner in younger patients (37%) versus older patients (12%)(p < .0001). Junctional melanocytic nevi were more frequently diagnosed in older patients (10% versus 3%; p = .027) and a lentiginous, often heavily pigmented, growth pattern was common (12% of nevi) vs control group (3%; p = .028). Atypical (“dysplastic”) nevi had a similar frequency at all ages, however 12/214 nevi in elderly patients (6%) exhibited marked atypia with features suggesting melanoma in‐situ. We conclude that benign junctional nevi are relatively common in elderly patients and that a lentiginous, heavily pigmented growth pattern, typically associated with younger patients, is often seen in both junctional and compound nevi in this older age group. This pattern must be differentiated from dysplastic nevus and melanoma in‐situ, which they may clinically resemble.

Subungual blue nevus

Junctional or compound melanocytic nevus and melanoma may involve the nail apparatus and are usually discussed in the differential diagnosis of nail pigmentation. Blue nevus has been very rarely reported in this location. We report the second clinicopathologic study of a subungual blue nevus.

Numerous, small, darkly pigmented melanocytic nevi: The cheetah phenotype

Background: The presence of multiple atypical nevi or numerous melanocytic nevi increases the risk for the development of cutaneous melanoma. Objective: We sought to describe a distinct clinical phenotype characterized by numerous (>100), small (≤4 mm), darkly pigmented melanocytic nevi that are uniform in color. Methods: Biopsy specimens from 6 patients (3 men and 3 women; age range, 44 to 81 years) with this clinical phenotype were reviewed and compared with a database of melanocytic lesions analyzed by the Yale Dermatopathology Laboratory (YDL) in the year 2000. Results: Of the 6 patients, 4 had multiple primary melanomas develop (n = 2-4), ranging from in situ to 1.0 mm in depth. The other 2 patients each had 1 nevus with severe cytologic atypia. When compared with the YDL database, our patients were more likely to have the following pigmented lesions: junctional melanocytic nevi, junctional lentiginous nevi, junctional nevi with cytologic atypia, and simple lentigines (P < .001). Conclusions: The longitudinal evaluation of patients with this phenotype can be challenging because similar-appearing pigmented lesions (small and uniformly dark-brown to black) had a range of histologic diagnoses from simple lentigo to junctional lentiginous nevus to thin melanoma. (J Am Acad Dermatol 2003;48:707-13.)

Positive Reactivity of Dysplastic Melanocytes with a Monoclonal Antibody Against Melanoma Melanosomes, MoAb HMSA-2

A mouse-mouse monoclonal antibody, MoAb HMSA-2, was raised against the melanosomal protein of human malignant melanoma. To characterize the nature of dysplastic melanocytic nevi (DMN), we examined the reactivity of DMN with MoAb HMSA-2 in comparison to that of superficial spreading melanoma (SSM) and common melanocytic nevi (CMN) including junctional melanocytic nevi (JMN) on routine paraffin sections. MoAb HMSA-2 showed several unique immunohistochemical findings: a) MoAb HMSA-2 reacted with melanocytes of DMN in both the epidermis and the dermis, including the pigment granules in the keratinocytes; b) the pigment granules in the keratinocytes of DMN were found to be immature melanosomes transferred from dysplastic melanocytes to keratinocytes; c) the reactivity of epidermal melanocytes in DMN and SSM was stronger than that of junctional component in CMN, though SSM revealed a much stronger reaction than DMN; and d) keratinocytes, especially in a "shoulder" lesion of DMN which was associated with dermal lymphocytic infiltrates, often showed a strong reactivity with MoAb HMSA-2. Thus our study suggested a unique immunohistochemical feature of DMN with deranged melanogenesis as indicated by the reactivity with MoAb HMSA-2.