Dermal Melanophages Research Articles

Understanding the anatomy of dermoscopy of melanocytic skin tumours: Correlation invivo with line-field optical coherence tomography.

Early melanoma detection is the main factor affecting prognosis and survival. For that reason, non-invasive technologies have been developed to provide a more accurate diagnosis. Recently, line-field confocal optical coherence tomography (LC-OCT) was developed to provide an invivo, imaging device, with deep penetration and cellular resolution in three dimensions. Combining the advantages of conventional OCT and reflectance confocal microscopy, this tool seems to be particularly suitable for melanocytic lesions. The objective of this study was to identify and describe the correlation between specific dermoscopic criteria and LC-OCT features in three dimensions associated with melanocytic lesions. Dermoscopic and LC-OCT images of 126 melanocytic lesions were acquired in three different centres. The following dermoscopic criteria have been considered: reticular pattern, dots and globules, structureless areas, blue-whitish veil, regression structures, negative network, homogeneous pattern, streaks and blotches. 69 (55%) benign and 57 (45%) malignant lesions were analysed. A regular reticular pattern was found associated in the 75% of the cases with the presence of elongated rete ridges with pigmented cells along the basal layer, while atypical reticular pattern showed an irregular organization of rete ridges with melanocytic hyperplasia, broadened and fused ridges and elongated nests. Both typical and atypical dots and globules were found associated with melanocytic nests in the dermis or at the dermoepidermal junction (DEJ), as well as with keratin cysts/pseudocysts. Grey globules corresponded to the presence of melanin-containing dermal inflammatory cells (melanophages) within the papillae. Structureless brown/black areas correlated with alterations of the DEJ. We observed the same DEJ alterations, but with the presence of dermal melanophages, in 36% of the cases of blue/white/grey structureless areas. A description of each LC-OCT/dermoscopy correlation was made. LC-OCT permitted for the first time to perform an invivo, 3D correlation between dermoscopic criteria and pathological-like features of melanocytic lesions.

Erythema Ab Igne Associated With Cannabinoid Hyperemesis Syndrome

A woman in her early 50s presented with a chronic rash and abdominal pain. The patient’s pain was relieved by prolonged hot showers. When the patient’s hot water ran out, she found that using a heating pad provided more sustained relief. She subsequently cut off the cover of heating pads to augment the temperature and used this continuously on her abdomen throughout the day. The patient smoked cannabis for 38 years but noticed stomach pain with the introduction of medicinal marijuana within the past 2 years. Physical examination demonstrated reticulated, hyperpigmented, and erythematous patches with desquamative scaling (Figure). A punch biopsy revealed a subepidermal blister with epidermal atrophy and dermal melanophages. Results of direct immunofluorescence were negative, confirming the diagnosis of bullous erythema ab igne. Erythema ab igne is a cutaneous disorder caused by chronic exposure to heat. Typical sources include space heaters, fireplaces, heating pads, and heating blankets. Rarely, squamous cell carcinoma can result. The treatment of choice is discontinuation of the heat source. Cannabinoid hyperemesis syndrome (CHS) is an increasingly reported disorder manifested by cyclical nausea, vomiting, or abdominal pain that is relieved by prolonged and extreme heat.1Chang Y.H. Windish D.M. Cannabinoid hyperemesis relieved by compulsive bathing.Mayo Clin Proc. 2009; 84: 76-78https://doi.org/10.1016/S0025-6196(11)60811-2Abstract Full Text Full Text PDF PubMed Scopus (96) Google Scholar Abstinence from the use of cannabis is the only known therapy to definitively treat the syndrome.2Simonetto D.A. Oxentenko A.S. Herman M.L. Szostek J.H. Cannabinoid hyperemesis: a case series of 98 patients.Mayo Clin Proc. 2012; 87: 114-119https://doi.org/10.1016/j.mayocp.2011.10.005Abstract Full Text Full Text PDF PubMed Scopus (247) Google Scholar In addition to heat, capsaicin topical cream has been used to alleviate abdominal pain. Haloperidol and droperidol may be used for nausea and vomiting symptoms.3Razban M. Exadaktylos A.K. Santa V.D. Heymann E.P. Cannabinoid hyperemesis syndrome and cannabis withdrawal syndrome: a review of the management of cannabis-related syndrome in the emergency department.Int J Emery Med. 2022; 15: 45https://doi.org/10.1186/s12245-022-00446-0Crossref Scopus (0) Google Scholar Use of cannabis (also referred to as marijuana, weed, or pot) among all age groups is rapidly rising. Duration and quantity of cannabis used are risk factors for CHS. The introduction of high-potency cannabis, with increased levels of tetrahydrocannabinol, might also be responsible for increased addiction and the emergence of CHS. The World Health Organization4World Health Organizationwww.who.int/teams/mental-health-and-substance-use/alcohol-drugs-and-addictive-behaviours/drugs-psychoactive/cannabisDate accessed: December 10, 2022Google Scholar and the Centers for Disease Control and Prevention5Centers for Disease Control and Preventionwww.cdc.gov/marijuana/health-effects/ index.htmlDate accessed: December 10, 2022Google Scholar do not specifically list CHS as an acute or chronic health effect of cannabis use. Many physicians are also unsuspecting of this syndrome. Physicians should be aware that abdominal erythema ab igne could be a dermatologic clue to CHS. Our patient was referred to an addiction specialist and directed to use capsaicin 0.1% cream to the abdomen 3 to 4 times daily. The authors report no competing interests.

Can we predict postinflammatory hyperpigmentation after laser treatment based on dermoscopic findings of solar lentigo?

Solar lentigo (SL) commonly occurs as hyperpigmented macules in areas exposed to ultraviolet radiation. It typically shows an increased number of melanocytes in the basal cell layer of the skin, with or without elongated rete ridges. This retrospective study aimed to evaluate the characteristic dermoscopic patterns, reflecting different histopathological features, which might be valuable in predicting the possibility of postinflammatory hyperpigmentation (PIH) occurring after laser treatment. In total, 88 Korean patients diagnosed with biopsy-proven SL (a total of 90 lesions were diagnosed) between January, 2016 and December, 2021 were included. Histopathological patterns were classified into six categories. Dermoscopic features were classified into six categories. Pseudonetwork pattern and rete ridge elongation showed a statistically significant negative correlation. This means that a flatter epidermis is likely to manifest as a pseudonetwork pattern. The erythema pattern showed a significant positive correlation with interface changes and inflammatory infiltration. Bluish-gray granules (peppering), a characteristic dermoscopic finding, showed significant positive correlations with interface changes, inflammatory infiltration, and dermal melanophages. Clinicians considering laser treatment for patients with SL should perform dermoscopic tests before treatment. The pseudonetwork relates to flattened epidermis and fewer Langerhans cells; thus, a lower remission of PIH after laser treatment might be expected. If bluish-gray granules or erythema are observed, inflammatory conditions are likely to be involved. In such cases, regression of the inflammatory response through drug therapy, such as topical corticosteroids, should be a priority option before laser treatment.

An Unusual Presentation of Lichen Striatus.

An Unusual Presentation of Lichen Striatus.

TOO HOT TO GET DRESSED?

TOO HOT TO GET DRESSED?

33379 Melanophages save the day: A case of generalized bullous fixed drug eruption

A 29-year-old female was seen via inpatient dermatology consultation for acute erosive stomatitis. Upon admission for sickle cell crisis, the patient had an incidental urinary tract infection and was treated with trimethoprim-sulfamethoxazole for 3 days. On physical examination, she had painful superficial erosions of the upper and lower mucosal lips extending onto the vermillion as well as the distal and ventral tongue. Five large dusky violaceous plaques with overlying superficial erosions were seen on the bilateral proximal medial thighs, arms and on the left lateral abdomen. Punch biopsy of the violaceous plaques revealed a vacuolar interface dermatitis with full thickness necrosis overlying an inflammatory infiltrate with occasional interstitial eosinophils and many melanophages at the level of the superficial vascular plexus. While the pathologic differential diagnosis included EM as well as SJS/TEN, the melanophages, eosinophils and clinical findings favored a diagnosis of generalized bullous fixed drug eruption (GBFDE) secondary to trimethoprim-sulfamethoxazole. GBFDE is a particularly severe variant of FDE which often includes mucosal erosions. Differentiation from SJS/TEN may sometimes be clinically and histologically difficult, and patients may suffer high morbidity and mortality. In our patient, we treated aggressively and cautiously with IV methylprednisolone followed by oral prednisone with no disease progression and eventual complete resolution. The clinical findings suggestive of FDE along with dermal melanophages and eosinophils allowed a cautious but confident diagnosis of GBFDE without need for transferring our patient to a burn unit.

34813 Acquired dermal melanocytosis on the hand of a Hispanic patient

Introduction: Case reports of acquired dermal melanocytosis on the hand are infrequent. This entity is usually seen in Asian population and the pathophysiology remains unclear. Skin biopsy is necessary to make the diagnosis with histopathologic findings of spindle-shaped cells with melanin granules in the superficial and middle dermis with or without presence of dermal melanophages. We present the first case of this rare dermatosis reported in Northern Mexico.

A longitudinal comparative study by in vivo harmonic generation microscopy: Q‐switched ruby laser versus picosecond 532‐nm Nd: YAG laser for the treatment of solar lentigines

AbstractBackgroundNanosecond quality‐switched ruby laser (QSRL) and frequency‐doubled 532‐nm picosecond Nd:YAG laser (532‐nm picosecond Nd: YAG laser [PSNYL]) are well‐documented treatments for solar lentigines (SLs). However, no studies have longitudinally tracked the microscopic findings before and after QSRL and 532‐nm PSNYL treatment for SL removal.ObjectivesTo compare the clinical efficacy and dynamic histological changes between QSRL and 532‐nm PSNYL in the treatment of SLs in Asian patients.MethodTwenty‐five patients with SLs on both sides of the face were enrolled in this prospective split‐face study. QSRL and 532‐nm PSNYL therapy for SLs on the left and right side of the face, respectively, were performed for each subject. All subjects underwent baseline and follow‐up assessment at Weeks 3 and 6. In vivo harmonic generation microscopy (HGM) imaging was adopted for the noninvasive observation of melanin mass density of basal cells (MMDbasal cell), epidermal melanocyte dendricity, and dermal melanophages before and after laser treatment.ResultsAt Week 6, 60% of the lesions treated with QSRL and 68% with 532‐nm PSNYL had over 75% improvement. Histologically, both lasers resulted in statistically significant decrease of MMDbasal cell in SLs to the level of that in the normal skin at Weeks 3 and 6. Statistically significant increase of dermal melanophages was observed 3 weeks after both laser treatments. Nevertheless, 532‐nm PSNYL led to faster clearance of melanophages than QSRL at Week 6. Moreover, activated melanocytes with enhanced dendrite formation was significantly increased till 6 weeks after both laser treatments.ConclusionBoth QSRL and 532‐nm PSNYL were effective treatments for SLs, and there was no statistically significant difference in clinical scoring. However, from histological aspect, 532‐nm PSNYL was associated with lower degree of melanin incontinence and melanophage accumulation. HGM imaging analysis can noninvasively quantitate the cutaneous response to pigmentary laser therapy.

Pigmented Actinic Keratosis Versus In Situ Melanoma: PRAME May Be Helpful

To the Editor: Since its introduction, the diagnostic utility of PReferentially expressed Antigen in Melanoma (PRAME) has been investigated with variable results.1–5 In general, PRAME shows strong and diffuse expression in most malignant melanocytic tumors, demonstrating high sensitivity and specificity for primary and metastatic melanomas. In some subsets, such as in the evaluation of lentigo maligna (LM), PRAME immunoreactivity is a sensitive and specific method to determine the malignant nature of the lesion and to assess tumor margins.6 However, in sun-exposed skin of the elderly, pigmented actinic keratosis (PAK), a variant of actinic keratosis in which melanin may be present in the keratinocytes of the lower epidermal layers, in melanocytes, or in dermal melanophages, represents a challenging differential diagnosis that has crucial therapeutic implications, as it can be treated conservatively, while in situ melanoma would require a potentially disfiguring re-excision, if located in the head and neck region. Although noninvasive diagnostic methods, such as dermoscopy and reflectance confocal microscopy, have been shown to improve the discrimination between in situ melanoma and PAK,7,8 differential diagnosis remains challenging. Thus, a biopsy could be required in equivocal cases along with ancillary histological techniques. The use of immunohistochemistry has yielded conflicting results. Melan-A tends to overestimate the number of melanocytes in sun-exposed skin,9 while MITF-1 and SOX10 are reliable markers for melanocytic quantification.10 In this study, we describe our experience with PRAME on 2 different pigmented lesions in the sun-exposed skin of the same patient. An 86-year-old man presented for the evaluation of a flat, irregularly pigmented macule on the cheek (Fig. 1A, arrows) and a large, ill-defined, similar patch on the vertex (Fig. 1B, arrows), for which he underwent 2 punch biopsies. Histological examination revealed severe actinic dermal damage in both cheek (Fig. 2A) and scalp (Fig. 2B) specimens, with thick elastosis and vascular ectasias. In the cheek, atypical basal keratinocytes were present, with large nuclei, visible nucleoli, and altered maturation. Some pigmented melanophages were also seen in the superficial dermis (Fig. 2A). Keratinocyte stratification was regular in the scalp, but some small hyperchromatic cells were unevenly lined at the dermal–epidermal junction (Fig. 2B).FIGURE 1.: A, An irregular, brownish macule on a sun-damaged cheek. B, A large, ill-defined pigmented patch on the scalp. Margins are macroscopically unpredictable.FIGURE 2.: A, Some atypical keratinocytes are present in the basal layers, with large nuclei, visible nucleolus, and altered maturation; few pigmented melanophages can be seen in the superficial dermis. B, Keratinocyte stratification is regular, but some small hyperchromatic cells are unevenly lined at the dermal–epidermal junction. The actinic dermal damage is severe both in the cheek and in the scalp. C and D, Melan-A staining is superimposable in the cheek (C) and in the scalp (D). E and F, PRAME stains few elements in the cheek (E) and is diffusely positive in the scalp (F).Although Melan-A showed similar results in both lesions (Figs. 2C, D), PRAME decorated very few elements in the cheek (Fig. 2E) and was diffusely positive in the scalp (Fig. 2G). Based on these morphological and immunohistochemical results, the macule on the cheek was diagnosed as PAK, while the lesion on the scalp was called a cell-poor early in situ melanoma (MIS) with an LM growth pattern. It may be difficult to distinguish early MIS with an LM pattern from other lesions occurring in chronically sun-exposed skin, such as solar lentigos, nevi, and actinic keratosis, or even from normal sun-exposed skin that carries an increased number of melanocytes per se. The LM growth pattern is characterized by continuous single-cell proliferation, with no or very little nesting, little pigmentation, and no pagetoid spread along the epidermis. Tumor cells are cytologically bland and are usually located along the dermo–epidermal junction. There is a typical loss of mutual spatial relations and crowding in the epidermal basal layer; however, these features can be extremely deceptive, especially in the early phases. Sometimes, these inconspicuous findings contradict the worrisome clinical picture, recalling the important issue of clinicopathological correlation when evaluating bladder melanocytic lesions. Similarly, actinic keratosis can show mild keratinocyte dysplasia involving only the basal epidermal layers, thus being either underdiagnosed as reactive changes or misdiagnosed as early MIS, especially if keratinocytes are pigmented, as in the present case. PRAME has recently been found to be a useful marker for distinguishing benign from malignant lesions in re-excision specimens with abundant reactive melanocytic hyperplasia, as in the head and neck region. In our patient, PRAME helped in the differential diagnosis with clinical implications. The PAK was treated with cryotherapy with a complete clinical response, while the LM is currently undertreatment with imiquimod 5% cream because of patient comorbidities.

Dermoscopic classification of melasma: Concordance study and correlation with the melanophages count.

Melasma is a common hypermelanosis characterized by symmetrical brownish macules, especially on the face. Histologic analysis demonstrates increased epidermal and dermal melanin. Dermoscopy is useful to estimate the depth of the melanin and may help in the diagnosis and classification of melasma, with therapeutic importance. To evaluate the diagnostic concordance of dermoscopic classification of epidermal or mixed subtypes of melasma and the correlation between dermoscopic and histopathological findings. Twenty-eight women with facial melasma, phototypes III to V, ages between 30 and 61 years were selected. Based on the evaluation of clinical and dermoscopic images, two independent observers classified melasma into epidermal or mixed subtypes. The intra and interobserver concordances were calculated. Histopathological analysis of epidermal melanin extension and maximum number of melanophages per high-power field (400×; HPF) have been assessed. Association between the melanophages count and the dermoscopic classification was evaluated. Intraobserver agreement was 82.1%, and between observers, from 78.6% to 89.3%, according to the Kappa index. Histopathology revealed increased intraepidermal melanin and the presence of dermal melanophages in all the samples. Ten or more melanophages/HPF was significantly associated with mixed melasma. Moderate to substantial concordance in the dermoscopic classification of melasma was found, and the correlation between this classification and the dermal melanophages count have been suggested. Intradermal component of every case of melasma should be considered for therapeutic and prognostic purposes.

Histopathological Changes Induced by Malassezin: A Novel Natural Microbiome Indole for Treatment of Facial Hyperpigmentation.

Malassezin is a natural indole compound produced by the fungus Malassezia furfur and preclinical investigations have demonstrated an ability to suppress melanogenesis. To investigate the histopathological effects of malassezin for treatment of facial hyperpigmentation. In this proof-of-concept study, seven subjects with facial hyperpigmentation caused by melasma or photodamage applied topical malassezin twice daily for 14 weeks, followed by eight weeks of observation. At baseline, 2 mm punch biopsies were taken from hyperpigmented areas and adjacent uninvolved skin. Skin biopsies from hyperpigmented areas were repeated at 8, 14, and 22 weeks. Paraffin-embedded sections were cut and stained with H&E, Fontana Masson, and MART 1 and assessed for histopathological changes. Increased epidermal melanin and dermal melanophages were observed in all biopsies at baseline in the hyperpigmented compared to uninvolved skin of all subjects. Eight and 14 week biopsies of involved skin revealed decreased epidermal melanin in all subjects treated with malassezin. Melanocytes appeared less dendritic compared to baseline, and numbers were slightly reduced at eight weeks. Biopsies at 22 weeks showed no significant difference in epidermal melanin levels compared to baseline hyperpigmented skin, and melanocytes were comparable in number and dendricity to baseline. There was no evidence of melanocyte atypia in any of the biopsies. These features were similar in melasma and photo-damaged skin. This study documents the histopathological features and ability of malassezin, a novel agent unique to the skin microbiome, to decrease epidermal pigmentation and the temporary and revisable nature of the process. J Drugs Dermatol. 2022;21(2):141-145. doi:10.36849/JDD.6596.

Erythema Dyschromicum Perstans: The Spotty Possibility – A Rare Case Report

Erythema Dyschromicum Perstans (EDP) / Ashy Dermatosis are a less common dermatological disorder with an unknown etiology. It is characterized by asymptomatic, grey, symmetric and confluent macules all over the body. Herein, we report a case of a 50 years old man who presented clinically, with diffuse, patchy pigmentation having ill-defined, erythematous borders involving bilateral arms and forearms. Histopathological examination of the lesion biopsy demonstrates vacuolar degeneration of the basal cell layer, dermal perivascular mononuclear cell infiltrate and increased epidermal melanin pigment and presence of dermal melanophages. For the present case, treatment with Clofazimine has proven to be effective.

Clinical, dermoscopic, and histopathologic evaluation of vitamin C versus PRP , with microneedling in the treatment of mixed melasma: A split‐face, comparative study

Melasma is a common esthetic problem affecting the face with a lot of risk factors being incriminated. Although several treatment options are available, none of them is satisfactory. This split face prospective study aimed to compare the efficacy of microneedling with vitamin C versus with platelet-rich plasma (PRP) in the management of mixed melasma. Ten females with bilateral mixed facial melasma were treated with six sessions of microneedling. After the needling vitamin C was applied on the right side of the face and PRP was applied on the left side. Clinical, dermoscopic, and histological assessment of the used treatments was done 1 month after the last session. The clinical and dermoscopic clearance of melasma was proved significantly on both sides of the face but was more significant with vitamin C (P= 0.005). Reduction of epidermal melanin and dermal melanophages was more observed with vitamin C. Moreover, MART-1 stain revealed a more significant reduction in the epidermal, dermal, and the total MART-1 positive cells with vitamin C (P= 0.044, 0.039, and 0.035, respectively). Microneedling with vitamin C was more efficient in treating mixed melasma than with PRP.

The study of epidemiological, clinical, histopathological and dermoscopic features of lichen planus

<p class="abstract"><strong>Background:</strong> Lichen planus (LP) is a common papulosquamous condition seen by the dermatologists. It can involve the skin, mucous mebranes, hair and nails. There are many subtypes of LP with various clinical, histopathological and dermoscopic features. In this study we intended to study the epidemiological, clinical, histopathological and dermoscopic features of LP.</p><p class="abstract"><strong>Methods:</strong> A total of 73 patients of LP, above the age of 18 years who qualified the inclusion and exclusion criteria were included in the study. A proforma of epidemiological details was noted, clinical and dermoscopic examination of the lesions were done. The punch biopsy specimens of cutaneous lesions were subjected to histopathological examination and the findings noted.</p><p class="abstract"><strong>Results:</strong> Out of the 73 patients included in the study, 44 were males and 29 females with a ratio of 1.51:1. Classic LP was the commonest type of LP. Wickham’s striae (WS) was the most typical and commonest dermoscopic feature of cutaneous LP except lichen planus pigmentosus. Hyperkeratosis, hypergranulosis, acanthosis, band shaped lymphocytic infiltrate, melanophages, basal cell degeneration and saw tooth shaped rete ridges were the significant histopathological features.</p><p class="abstract"><strong>Conclusions:</strong> LP is more common in young adults and shows a male preponderance. WS is the most important diagnostic feature seen on dermoscopy of all the cutaneous types of LP excluding LPP. Interface dermatitis with a band of lymphocytic infiltrates and dermal melanophages is a notable feature of histopathology of LP.</p>

Primary cutaneous amyloidosis: A clinicopathological, histochemical, and immunohistochemical study.

Primary cutaneous amyloidosis (PCA) comprises several forms of localized cutaneous amyloidosis characterized by amyloid deposits occurring at or near dermal-epidermal junctions. Immunohistochemical studies have shown the expression of cytokeratin (CK) suggesting that it has an epidermal origin. To study the clinicopathological features of PCA and expression of CK5/6 and correlate it with Congo red stain. A total of 30 histologically proven cases of PCA were studied. Congo red staining and immunohistochemical expression of CK5/6 were analyzed. : The qualitative data has been expressed as proportions and the quantitative data has been expressed as mean ± SD. All data was analyzed using the Statistical Package for Social Sciences (SPSS) software version 22. Deposits of amyloid in papillary dermis were seen in all 30 cases. Mild focal basal cell vacuolar degeneration and apoptotic bodies in epidermis were seen in six cases. The presence of pigment cells in dermis were seen in 26 cases. CK5/6 showed weak/mild immunopositivity in nine cases, moderate in 20 cases, and strong in one case. The presence of dermal melanophages interspersed within eosinophilic deposits gives a clue to the diagnosis. Congo red stain highlights the deposits and visualization under polarized light gives apple green birefringence which is diagnostic of amyloid. Staining of amyloid deposits by CK5/6 proves that the amyloid is of keratinocyte origin. There was 100% sensitivity with Congo red and CK5/6. Thus, CK5/6 can be used as an adjunct tool to Congo red stain in the diagnosis of primary cutaneous amyloidosis.

Does signal transducer and activator of transcription-3 have a role in lichen planus?

ObjectiveThe aim was to evaluate the role of signal transducer and activator of transcription 3 (STAT3) in lichen planus (LP).BackgroundLP is a chronic mucocutaneous T-cell-mediated inflammatory disease. STAT3 is responsible for signal transmission to the nucleus from many receptors and nonreceptor-associated kinases.Materials and methodsA prospective case–control study was conducted on 20 cases with LP and 20 age-matched, sex-matched, and localization-matched apparently healthy participants. All sections were immunohistochemically stained for STAT3.ResultsThere were significant differences between the studied groups regarding STAT3 positivity in both dermis and epidermis (P = 0.043 for both), as well as STAT3 intensity of expression in epidermis and dermis (P = 0.008 and 0.001, respectively). There were significant associations between moderate and strong STAT3 expression and generalized lesions, presence of precipitating factors, presence of dermal melanophages, and presence of moderate spongiosis (P = 0.01, 0.005, 0.05, and 0.04, respectively).ConclusionOverexpression of STAT3 in LP could play a role in pathogenesis and severity of LP. Anti-STAT3 target therapy might be suggested to ameliorate LP.

A clinical, dermoscopic, histopathological and immunohistochemical study of melasma and facial pigmentary demarcation lines in the skin of color.

Melasma and facial pigmentary demarcation lines (FPDL) are common causes of patterned facial pigmentation that may mimic each other. There is a paucity of studies investigating these two conditions. The objective of this study was to make a detailed comparative analysis of these disorders. A clinical, dermoscopic, histopathological and immunohistochemical analysis of lesional and perilesional skin was conducted in 20 patients each of melasma and FDPL. The most common morphological patterns were centrofacial in melasma and W-shaped pattern in FPDL. Dermoscopy in melasma revealed similar patterns in lesional and perilesional skin, whereas FPDL did not. Histopathology of melasma revealed increased melanin in the suprabasal and basal layers (100%), melanophages in the upper dermis and solar elastosis (65%) in contrast to FPDL, wherein increased basilar melanin (75%) and dermal melanophages were the key findings. Expression of vascular endothelial growth factor and stem cell factor was slightly increased in lesional melasma skin, but not in FPDL. The study was limited by its small sample size and immunohistochemistry carried out in a few patients. Melasma and FPDL, although similar in presentation, are distinct entities. Dermoscopy, histology and immunohistochemistry reveal subtle differences.

Diagnostic dermoscopic features and the correlation between dermoscopic and histopathologic features in lichen planus

<p class="abstract"><strong><span lang="EN-US">Background: </span></strong><span lang="EN-US">Lichen planus (LP) is an autoimmune dermatosis characterized by pruritic violaceous flat-topped polygonal papules predominantly over the extremities but can also affect trunk, mucosa, scalp, palms, soles and nails. Dermoscopy is a novel non-invasive imaging modality and the presence of salient dermoscopic features will help to obviate the need for skin biopsies in many doubtful cases.<strong></strong></span></p><p class="abstract"><strong><span lang="EN-US">Methods: </span></strong><span lang="EN-US">This was a descriptive study of 108 cases of classical lichen planus cases conducted at a tertiary care hospital in South India over a period of one year. Dermoscopic examination of the LP lesions were carried out using DermLite DL3N and histopathological samples were analyzed in 35 cases.<strong></strong></span></p><p class="abstract"><strong><span lang="EN-US">Results: </span></strong><span lang="EN-US">The dermoscopic features were blue globules in 100%, Wickham’s striae in 92.6% and comedo like openings in 49.1%. Vascular patterns were noted only in 13%. On correlating Wickham’s striae in dermoscopy with wedge shaped hyper granulosis on histopathology using the chi-square test we found agreement (kappa value 0.242). We also found that dermoscopy was 93.75% sensitive and 33.33% specific regarding Wickham’s striae in relation to wedge shaped hyper granulosis. In 85% of cases blue globules were present dermoscopically and dermal melanophages were found histopathologically.<strong></strong></span></p><p class="abstract"><strong><span lang="EN-US">Conclusions: </span></strong><span lang="EN-US">Wickham’s striae can be considered as a diagnostic dermoscopic finding in lichen planus whereas findings like bluish pigmentation and vascular structures depended on the skin colour of the patient. We also found agreement between dermoscopic and histopathologic features namely Wickham’s striae with wedge shaped hyper granulosis and blue globules with dermal melanophages.<strong></strong></span></p>

Establishment of a mouse model for post-inflammatory hyperpigmentation.

Post-inflammatory hyperpigmentation (PIH) is a common cutaneous condition that can cause a disfigured appearance. However, the pathophysiology of PIH remains poorly understood, at least in part, because an appropriate animal model for research has not been established. In order to analyze the pathomechanism of PIH, we successfully induced PIH in a hairless version of transgenic mice (hk14-SCF Tg/HRM) that have a human-type epidermis containing melanin by repeated hapten application of 2,4-dinitrofluorobenzene. Histopathologic observation showed epidermal hyperplasia, predominant infiltrations of inflammatory cells, and melanin-containing cells in the dermis just after elicitation of the atopic dermatitis-like condition. At week 2, the findings were similar to the characteristics of PIH, that is, an increase of melanin without spongiosis or liquid degeneration in the epidermis and an increase in dermal melanophages. Dynamic analysis of melanin showed that the melanin in the dermis remained for a longer duration than in the epidermis. Furthermore, immunohistochemical staining revealed that the majority of cells containing melanin were positive for the anti-CD68 antibody, but negative for the anti-F4/80 antibody. These data suggest that novel treatments of PIH should be targeted against macrophages and should eventually lead to the development of new treatment modalities.

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.