Irregular Diffuse Pigmentation Research Articles

Hutchinson Sign: Biopsy May Assist in Diagnosis of Subungual Melanoma in Situ.

Early and accurate diagnosis of subungual melanoma (SUM) through histopathologic examination is critical, but lack of clinical suspicion leads to delays in diagnosis. Hutchinson sign (HS) can be one of the important clinical indicators for diagnosing SUM. To evaluate the diagnostic value of small biopsies of HS for detecting SUM in situ. We retrospectively evaluated 12 patients who were diagnosed as SUM in situ and underwent punch biopsy at HS areas. Clinical features, dermoscopic findings, and histopathologic findings in HS regions were analyzed. In most cases, HS was seen in hyponychium (11/12, 91.7%) with 1 case found in proximal nail fold, and 1 case in both the hyponychium and proximal nail fold. Dermoscopic features of HS showed irregular diffuse pigmentation (12/12, 100%) and parallel ridge pattern (7/12, 58.3%). Histopathologically, all cases showed irregularly scattered atypical melanocytes with hyperchromatic nuclei. Two cases showed subtle changes in melanocytes with little nuclear atypia, but additional section specimen showed more definitive findings of SUM in situ. We present a supplementary biopsy technique for diagnosing SUM. Biopsy of HS may help in the diagnosis of SUM.

Acral lentiginous melanoma in situ: dermoscopic features and management strategy

Diagnosis of acral lentiginous melanoma in situ (ALMIS) is challenging. However, data regarding ALMIS are limited in the literature. The aim of this study was to investigate the clinical and dermoscopic features of ALMIS on palmoplantar surfaces. Patients with ALMIS and available dermoscopic images were retrospectively reviewed at our institution between January 2013 and February 2020. Clinical and dermoscopic features were analysed and compared between small (< 15 mm) and large (≥ 15 mm) ALMIS. Twenty-one patients with ALMIS were included in this study. Mean patient age was 58.5 (range 39–76) years; most lesions were located on the sole (90.5%). The mean maximal diameter was 19.9 ± 13.7 mm (mean ± standard deviation). Statistical analysis of dermoscopic features revealed that parallel ridge patterns (54.5% vs. 100%, P = 0.035), irregular diffuse pigmentation (27.3% vs. 100%, P = 0.001) and grey colour (18.2% vs. 90%, P = 0.002) were significantly less frequent in small lesions than in large lesions. We have also illustrated two unique cases of small ALMIS; their evolution and follow-up dermoscopic examination are provided. In conclusion, this study described detailed dermoscopic findings of ALMIS. Based on the present study and a review of the literature, we proposed a dermoscopic algorithm for the diagnosis of ALMIS.

Acral lentiginous melanoma in the Turkish population and a new dermoscopic clue for the diagnosis.

BackgroundThe incidence of acral lentiginous melanoma (ALM) in the white population is low. Dermoscopy enhances diagnosis of ALM; however, diagnostic accuracy may sometimes be poor due to the considerable proportion of amelanotic ALM variants.ObjectivesTo calculate the proportion of ALM among all melanoma subtypes and to determine the frequency of dermoscopic features of ALM in the Turkish population.MethodsOut of 612 melanomas, there were 70 cases of ALM, of which 46 showed sufficient image quality for retrospective study of dermoscopic features. Data from patients and their lesions was classified according to clinical features and histopathologic parameters. The dermoscopic variables evaluated were based on pertinent literature on dermoscopy of acral melanocytic neoplasms.ResultsThe prevalence of ALM among all melanoma subtypes was 11.4%. Parallel-ridge pattern (PRP) was detected in 60.8% of cases and irregular diffuse pigmentation (IDP) in 28.3%. The ALMs were amelanotic in 24%, showing an atypical vascular pattern in all cases; a new dermoscopic pattern, named “vascularized parallel-ridge pattern” (VPRP), was detected in 13% of ALMs. Irregular lines were observed in 81.8% of subungual melanomas and were often associated with a multicolored background.ConclusionsALM has site-specific dermoscopic patterns, with PRP being the most prevalent pattern. The newly described VPRP pattern may be an additional clue for ALM diagnosis, especially in thin amelanotic melanomas.

Acral melanoma: correlating the clinical presentation to the mutational status.

Acral lentiginous melanoma (ALM) is the most common type of malignant melanoma (MM) in Asians, Afro-Americans and Middle-Easterners. It represents 1.5-10% of all MM cases, being the most common histological type of MM arising on palms, soles and nail apparatus, which is more generically defined as acral MM. To date no risk factors have been officially established, however a history of trauma may be involved in the pathogenesis of acral MM. This shows heterogeneous clinical features and frequently presents with advanced stage and aggressive behavior, often as a result of misdiagnosis or delayed identification. Dermoscopy is helpful for an early diagnosis of ALM: the most characteristic dermoscopic patterns are the parallel ridge and the irregular diffuse pigmentation. On histopathology ALM displays a lentiginous growth pattern, with melanocytes arranged as solitary units along the basilar epidermis, without notable pagetoid growth in the early stage. Not all acral MMs present a lentiginous pattern: superficial spreading melanoma and nodular melanoma patterns are also possible. Novel studies investigating the biologic characteristics of acral MM reported variable results: the overall mutational rates ranged respectively between 8.5% and 23% for KIT, between 3.6% and 33.3% for BRAF and between 3% and 47% for NRAS in ALMs. Increasing attention has been recently given to other genes, such as telomerase reverse transcriptase, platelet-derived growth factor receptor alfa and cyclin D1. Larger molecular investigations urge to describe the molecular profile of acral MM, to allow the development of specific targeted therapies.

Dermoscopic features of conjunctival, mucosal, and nail pigmentations in a case of Laugier-Hunziker syndrome.

A 23-year-old man presented with multiple lip pigmentations. Longitudinal hyperpigmented streaks on his nails, as well as an ill-defined 2×3 mm pigmented spot on his right eye were noted (Figure 1). The family history was unremarkable. He was not taking any medication. Figure 1. Clinical view of labial (A), ungual (B) and conjunctival (H) pigmentations are shown. Dermoscopic findings included reticular lines (B), globules (C), and parallel lines (D) in the labial pigmentation; brown to gray longitudinal regular lines (F, G) in ... Colonoscopy and barium radiography of intestine were unremarkable. Complete blood count, complete metabolic panel, and urinalysis were within normal limits. The patient was diagnosed with Laugier-Hunziker syndrome (LHS). Dermoscopic examination of the lip pigmentations disclosed parallel lines, reticular lines and globules. The only recognized color was brown, which had a grayish hue in some parts of the lesion. A light brown colored homogeneous pattern was observed in the conjunctival pigmentation. The pigmented nail streaks showed brown-to-gray longitudinal regular lines (Figure 1). Histopathological examination of the labial pigmentation revealed basal keratinocyte pigmentation. No increase in the melanocyte count was identified with S100 and HMB45 immunohistochemical staining. Iron accumulation was not seen with specific Perls’ stain. The histopathological findings were compatible with the diagnosis of melanotic macule. Impression cytology examination of the conjunctival pigmentation revealed melanocytes with only a mild atypia suggesting a benign nature. The patient was processed to follow-up. LHS is a rare, acquired disease characterized by hyperpigmented macules of the lips and oral mucosa along with longitudinal melanonychia. Pigmentations in other mucosal surfaces may also exist. Although this syndrome is being regarded as benign, invasive mucosal melanoma has been reported in a case of LHS [1]. Parallel ridge pattern and irregular diffuse pigmentation in acral lesions; irregular lines on a brown background and micro-Hutchinson’s sign in nail apparatus lesions [2]; and the combination of blue, gray, or white color with structureless zones in mucosal lesions are the dermoscopic findings suggestive of melanoma [3]. Little data exists regarding the dermoscopic features of conjunctival pigmentations in the literature. Atypical pigment network, irregular dots and globules, regression structures, and a blue-white veil are the dermoscopic findings reported in a case of palpebral conjunctival melanoma [4]. Dermoscopic findings may differ from usual in some pigmentation syndromes including LHS. Parallel ridge pattern has been determined in benign acral pigmentations of several LHS cases [5–7]. Although nail pigmentations in LHS have been found to demonstrate similar dermoscopic findings with that seen in ethnic type and drug induced pigmentation, which are regular linear pigmentation lines on a grayish background, micro-Hutchinson’s sign have also been reported in benign nail pigmentations of some LHS cases [2,5,8]. Parallel furrow pattern, brown and blue-gray granular pigmentation along with linear and dotted vessels on whitish pink areas are the dermoscopic findings reported in labial pigmentations of LHS cases [5]. The only LHS case with labial melanoma in the literature exhibited blue-whitish veil on dermoscopic examination [1]. Dermoscopic findings in the present case were consistent with benign nature. The dermoscopic finding of a conjunctival pigmentation in LHS is being reported for the first time by the present study. The identification of dermoscopic features of this syndrome may simplify the management of LHS. Further reports are necessary to arrive at a conclusion.

Special Locations Dermoscopy

Although dermoscopy reflects the anatomy, skin anatomy is different on facial and acral skin as well as in the nail unit. Malignant patterns on acral sites include the parallel ridge pattern and irregular diffuse pigmentation, whose presence should lead to a biopsy. Malignant patterns on the face include features of follicular invasion (signet-ring images, annular granular images, and rhomboidal structures) and atypical vessels. Malignant patterns on the nail unit include the micro-Hutchinson sign and irregular longitudinal lines.

Dermoscopic features of melanocytic lesions on volar skin: 178 case reports

Objective To investigate the dermoscopic features of palmoplantar melanocytic lesions.Methods The dermoscopic images of palmoplantar melanocytic lesions that underwent examination in the Department of Dermatology in Peking University First Hospital from September 2009 to October 2011,were retrospectively analyzed.Results Totally,155 benign acral melanocytic lesions in 121 patients and 23 acral melanomas in 22 patients were analysed in this study.Among the benign acral melanocytic lesions,the parallel furrow pattern and its variations (34.2％) were the most common,followed by the fibrillar pattern (22.6％).Two benign lesions (1.3％) showed a parallel ridge pattern.Of 23 melanoma lesions,12 (52.2％) exhibited parallel ridge pattern,and 14 (60.9％) showed irregular diffuse pigmentation that was present in all of the invasive melanoma lesions.The fibrillar pattern,as a common benign acral dermoscopic pattern,was also present in 39.1％ of melanoma specimens.Conclusions Dermoscopy is valuable to some extent in the differential diagnosis of benign melanocytic nevi and malignant melanoma in palmoplantar region,and may facilitate the secreening for early melanoma.

Dermoscopic features of acral lentiginous melanoma in a large series of 110 cases in a white population

Acral lentiginous melanoma (ALM) is a rare but distinctive subtype of melanoma. The diagnosis is often delayed and misdiagnosis is common, due to frequently unusual clinical presentation and a higher rate of amelanosis than in other melanoma subtypes. We aimed to investigate the dermoscopic features of a large series of ALM in a white-skinned population, in order to emphasize their diagnostic value. All recorded dermoscopic photographs of ALM, including nail unit variants, were collected from the files of the University Hospital Department of Dermatology (Lyons, France) and reviewed. In total 110 lesions, including 66 (60%) palmoplantar ALM and 44 (40%) ALM of the nail apparatus, were analysed for dermoscopic characteristics. The mean Breslow thickness was 2.6 mm. In volar skin melanomas, the two most prevalent patterns were irregular diffuse pigmentation (60%) and the parallel-ridge pattern (53%). Minor dermoscopic patterns, commonly noted in benign lesions, were also detected but only focally within the lesions. Among the 44 nail unit lesions, 31 (70%) presented irregular lines with variegations in colours, spacing, width and disruption of parallelism. Two cases of melanonychia striata had a triangular shape. Both corresponded to early ungual ALM. Association with subungual haemorrhage was not uncommon. The study included 37 (34%) amelanotic melanomas. However, dermoscopy enabled detection of microscopic remnants of pigmentation in most cases. The vascular pattern found in almost half of these lesions was polymorphous, with combinations of milky-red areas (95%), linear irregular vessels (49%), dotted vessels (43%) and hairpin vessels (41%). The presence of a parallel-ridge pattern and/or irregular diffuse pigmentation within the lesion is highly indicative of melanoma on volar skin. An irregular lines pattern is the most prominent dermoscopic feature of pigmented ALM of the nail apparatus. Amelanotic ALM either in volar skin or in nail apparatus is characterized by remnants of pigmentation and a polymorphic vascular pattern.

Significance of Dermoscopic Patterns in Detecting Malignant Melanoma on Acral Volar Skin

To determine diagnostic variables such as sensitivity and specificity of the major dermoscopic patterns observed in melanocytic lesions on acral volar skin, with particular attention to the significance of the parallel ridge pattern and irregular diffuse pigmentation in detecting acral melanoma. Multicenter, retrospective study. University hospitals in Japan. Patients with melanocytic lesions on acral volar skin. A total of 712 melanocytic lesions (103 malignant melanomas, including 36 in situ lesions, and 609 melanocytic nevi) were consecutively collected from the files of 3 hospitals. Diagnoses of all the lesions had been determined histopathologically. Dermoscopic examination. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of the major dermoscopic patterns seen in benign and malignant melanocytic lesions on acral volar skin. The parallel ridge pattern and irregular diffuse pigmentation showed extremely high specificity (99.0% and 96.6%, respectively) and very high negative predictive value (97.7% and 97.5%, respectively) in malignant melanoma. For melanoma in situ, the positive predictive value and diagnostic accuracy of the parallel ridge pattern were significantly higher than those of irregular diffuse pigmentation (P = .009 and P = .006, respectively). In melanocytic nevi, the specificity and positive predictive value of the parallel furrow pattern and/or the latticelike pattern were found to be very high (93.2% and 98.3%, respectively). Dermoscopy is immensely helpful in differentiating malignant melanomas from melanocytic nevi on acral volar skin. Moreover, the parallel ridge pattern aids in detecting acral melanomas in early, curable stages.

Dermatoscopic pitfalls in differentiating pigmented Spitz naevi from cutaneous melanomas

Epiluminescence microscopy (ELM, skin surface microscopy, dermoscopy, dermatoscopy) is a valuable method for improving the diagnostic accuracy in pigmented skin lesions. Specific ELM criteria are already recognized for differentiating pigmented Spitz naevi (PSN) from cutaneous melanomas (CM). Our purpose was to describe the ELM appearance of a series of PSN with emphasis on PSN and CM with overlapping features. Thirty-six consecutive patients with PSN, and three cases of CM (selected from a larger database) exhibiting ELM 'spitzoid' features, were evaluated clinically, dermatoscopically and histopathologically. Most PSN (27 of 36; 75%) displayed two typical ELM patterns, namely, the starburst (19 of 36; 53%) or the globular pattern (eight of 36; 22%), which were correlated to different histopathological findings. In nine of 36 (25%) PSN, atypical ELM features which are more commonly seen in CM were observed. These PSN with an atypical pattern were characterized by an uneven distribution of colours and structures, and an irregular diffuse pigmentation resembling blue-white veil or irregular extensions (black blotches). These atypical lesions mostly occurred in children and showed no history of growth. In contrast, in three examples of CM, the typical ELM criteria of malignancy were less recognizable and either the characteristic starburst or globular pattern usually seen in PSN was present. These three lesions occurred in adults and had a recent history of change in colour, shape or size. The overlap in ELM features of some PSN and CM represents a major diagnostic pitfall when ELM examination is considered alone. In these atypical cases, clinical history including the age of the patient may be the only clue to enable a correct diagnosis.