A comparison of dermoscopic features among lentigo senilis/initial seborrheic keratosis, seborrheic keratosis, lentigo maligna and lentigo maligna melanoma on the face

Clinical differentiation of facial lentigo senilis/initial seborrheic keratosis (LS/ISK), seborrheic keratosis (SK), lentigo maligna (LM), and lentigo maligna melanoma (LMM) can be difficult. Dermoscopy improves the diagnoses in pigmented skin lesions (PSLs), but it is not helpful for the sun-exposed face because of the flat rete ridges without network-derived features. Therefore, development of new diagnostic criteria for this particular localization is a current issue of dermatology. In this retrospective study, dermoscopic slides of facial pigmented skin lesions of 66 patients referred to two clinics in Turkey were evaluated. Our aim was to determine the reliability of dermoscopy in the differentiation of these entities. The facial PSLs of 66 patients (34 males and 32 females) (median age: 58.2) were photographed with a Dermaphot (Heine, Hersching, Germany) over a five year period from November of 1995 to May of 2000. All of the dermoscopic slides were analysed according to 27 dermoscopic criteria developed by Schiffner et al. This data set contained 22 histologically proven malignant (14 LM, 8 early LMM) and 44 benign (18 SK, 26 LS/ISK) PSLs. In general, asymmetric pigmented follicular openings, dark streaks, slate-gray streaks, dark globules, slate-gray globules, dark dots, dark rhomboidal structures, light brown rhomboidal structures, dark homogeneous areas and dark pseudonetworks were statistically significant for malignant growth. On the other hand, milia-like cysts, pseudofollicular openings, cerebriform structures, light brown globules, light brown dots, light brown homogeneous areas, yellow opaque homogeneous areas, and light brown pseudonetworks were statistically significant for benign growth. This research emphasizes that dermoscopic features on the face differ from criteria used in other locations of the body. Analysis of the data suggests that dermoscopy can be used in the differentiation of LS/ISK, SK, LM and LMM from each other.     

Folliculotropism in pigmented facial macules: Differential diagnosis with reflectance confocal microscopy

Pigmented facial macules are common on sun damage skin. The diagnosis of early stage lentigo maligna (LM) and lentigo maligna melanoma (LMM) is challenging. Reflectance confocal microscopy (RCM) has been proven to increase diagnostic accuracy of facial lesions. A total of 154 pigmented facial macules, retrospectively collected, were evaluated for the presence of already‐described RCM features and new parameters depicting aspects of the follicle. Melanocytic nests, roundish pagetoid cells, follicular infiltration, bulgings from the follicles and many bright dendrites and infiltration of the hair follicle (ie, folliculotropism) were found to be indicative of LM/LMM compared to non‐melanocytic skin neoplasms (NMSNs), with an overall sensitivity of 96% and specificity of 83%. Concerning NMSNs, solar lentigo and lichen planus‐like keratosis resulted better distinguishable from LM/LMM because usually lacking malignant features and presenting characteristic diagnostic parameters, such as epidermal cobblestone pattern and polycyclic papillary contours. On the other hand, distinction of pigmented actinic keratosis (PAK) resulted more difficult, and needing evaluation of hair follicle infiltration and bulging structures, due to the frequent observation of few bright dendrites in the epidermis, but predominantly not infiltrating the hair follicle (estimated specificity for PAK 53%). A detailed evaluation of the components of the folliculotropism may help to improve the diagnostic accuracy. The classification of the type, distribution and amount of cells, and the presence of bulging around the follicles seem to represent important tools for the differentiation between PAK and LM/LMM at RCM analysis.     

Dermoscopic features of actinic keratosis

Actinic keratosis (AK) is a keratinocytic neoplasm that typically develops on sun‐damaged skin of elderly individuals. Only a few reports so far have described the dermoscopic diagnostic features of AK, mainly focusing on facial non‐pigmented AKs. A typical feature of facial non‐pigmented AK is a composite pattern named “strawberry pattern”, characterized by a background erythema/red pseudonetwork consisting of unfocused, large vessels located between the hair follicles, associated with prominent follicular openings surrounded by a white halo. Dermoscopic characteristics of pigmented AK on the face include multiple slate‐gray to dark‐brown dots and globules around the follicular ostia, annular‐granular pattern and brown to gray pseudonetwork. Recognizing specific dermoscopic features of AK can be useful in guiding the clinician in the differential diagnosis of AK with melanocytic skin lesions such as LM and non‐melanocytic lesions. Histopathologic examination should be performed whenever clinical and/or dermoscopic differential diagnosis is inconclusive.     

Wachsende Pigmentl?sion der linken Wange

A 75-year-old man presented after recurrence of a pigmented macule on his left cheek. Approximately 8 month before a seborrheic keratosis had been diagnosed clinically and treated with cryosurgery and curettage. Dermatoscopy of the recurrent lesion revealed a number of criteria associated with lentigo maligna including asymmetric pigmented follicular openings, streaks, rhomboidal structures, and homogeneous slate-gray areas. Histopathology confirmed a lentigo maligna melanoma with a Breslow tumor thickness of 0.3 mm.     

Diagnostic utility of dermoscopy in pigmented actinic keratosis

The diagnosis of pigmented actinic keratosis can be complicated in clinical practice. The differential diagnosis with lentigo maligna melanoma can be difficult due to common clinical and dermoscopic characteristics. We present 5 cases of pigmented actinic keratosis in 4 patients. The most common dermoscopic finding was a grayish-brown granulation with a perifollicular distribution, present in all lesions, followed by rhomboidal structures in 4 cases, and an annular-granular pattern in 3. In no case were asymmetrical pigmented follicular openings observed. We draw attention to key findings that aid preoperative diagnosis of pigmented actinic keratosis.     

Key points in dermoscopic differentiation between lentigo maligna and solar lentigo

A clinical diagnosis of lentigo maligna at an early stage is often difficult even for experienced dermatologists. Differential diagnoses would include solar lentigo, early lesions of seborrheic keratosis, lichen planus-like keratosis, pigmented actinic keratosis and melanocytic nevus. Dermoscopy has been shown to have higher diagnostic accuracy, especially in the diagnosis of pigmented skin lesions, in the past two decades. To aim of the present study was to review the diagnostic key points on dermoscopy in the published work to differentiate lentigo maligna from other differential diagnoses and reassess these important features on dermoscopy for specificity by describing the findings in detail. Diagnostic key points for lentigo maligna/lentigo maligna melanoma on dermoscopy are asymmetrical pigmented follicular openings, rhomboidal structures, annular-granular structures and gray pseudo-network. Lentigo maligna, at first, seems to occur as asymmetrical pigmented follicular openings and/or annular-granular structures, then expand and develop into the rhomboidal structures. Annular-granular structures and gray pseudo-network seem to be observed also in regressive areas of solar lentigo/initial seborrheic keratosis, lichen planus-like keratosis and pigmented actinic keratosis. The four important criteria on dermoscopy for the diagnosis of lentigo maligna have been reviewed, and the former two criteria seem to be more specific, but it might be difficult to recognize these findings without misinterpretation. The latter two seem to be not so specific as they would also be demonstrated in other pigmented epidermal lesions, although the distribution of the structures in these disorders would be inclined to be more homogeneous than that of lentigo maligna.     

Dermatoscopy of pigmented actinic keratosis--a striking similarity to lentigo maligna

BACKGROUND: Pigmented actinic keratosis (PAK) resembles lentigo maligna (LM) clinically and histopathologically in some cases. OBJECTIVES: To describe the dermatoscopical characteristics of this uncommon variant of actinic keratosis and evaluate whether these characteristics show common features with LM. OBSERVATIONS: We had the opportunity to examine a 78-year-old woman who presented with a PAK lesion on her face dermatoscopically and histopathologically. The pigmented pseudo-network had black and gray dust in some areas, which were the main dermatoscopical features. The pigmented pseudo-network was formed by an unhomogenous brown background interrupted by regularly distributed hair follicules. The hyperpigmentation was based not only on an increased presence of melanin within the keratinocytes in the basal and spinous layers of epidermis, but also an intensive apoptosis of keratinocytes connected to numerous melanophages. CONCLUSIONS: The dermatoscopical picture of PAK in this patient was practically indistinguishable from the early stage of LM. The authors considered that the pigmented atypical melanocytes' role in LM presenting as black dots in the dermatoscopical picture was displayed by the individually pigmented keratinocytes in PAK. The groups of melanophages presenting as gray dust were present in PAK similarly to their presentation in LM. The character of the pigmented pseudo-network is the same in the both afflictions. There is a need to examine other cases of PAK in order to decide whether our case represents a general pattern of the dermatoscopical picture.     

Dermoscopy of lentigo maligna melanoma: report of 125 cases

Background Lentigo maligna melanoma (LMM) is the most common subtype of melanoma on the face. Its presentation may be quite subtle, particularly in early stages, and delayed diagnosis is common. Few dermoscopic studies have been performed and the main dermoscopic features of LMM were defined by Stolz and coworkers in 2000. Objectives To investigate classical as well as new dermoscopic features in a large series of LMM in a white‐skinned population, in order to evaluate their diagnostic value. Methods One hundred and twenty‐five consecutive histopathology‐proven LMMs were analysed retrospectively based on medical records, clinical and dermoscopic photographs by three independent observers for the presence of 19 predefined criteria. Results At least one of the classical Stolz criteria was present in 87% of cases (hyperpigmented follicular opening, annular‐granular pattern, pigmented rhomboidal structures, obliterated hair follicles). Three original criteria were also present at a relatively high frequency: increased density of the vascular network (58%), red rhomboidal structures (40%), target‐like patterns (41%). Darkening at dermoscopic examination (when compared with naked‐eye examination) was observed in 25% of lesions. Classical dermoscopic features of extrafacial melanoma (atypical pigment network, irregularly distributed globules, dots, streaks and pseudopods) and vertical growth phase‐associated dermoscopic criteria (ulceration, blue papular areas and black structureless areas) were rarely seen. A large number of colours, pigmented rhomboidal structures, obliterated hair follicles and red rhomboidal structures were significantly more frequent in invasive LMMs. In contrast, in situ melanomas were more often associated with one or two colours and few distinctive dermoscopic features. Conclusions We present herein, in a large series of LMM, confirmation of the diagnostic value of the classical Stolz dermoscopic criteria and describe four additional original criteria, mainly vascular. A correlation between the presence of some dermoscopic features and thicker tumoral invasion has also been demonstrated.     

Dermoscopic and clinical features of head and neck melanoma

BACKGROUND

The dermoscopic criteria of extrafacial melanomas are well-known.

OBJECTIVE

To determine the frequency of dermatoscopic findings in head and neck melanomas (HNM) and to assess the distinguishing dermoscopic criteria of facial and extrafacial melanoma.

METHODS

This observational study included 108 patients with HNM (63% male, mean age 64 years). Participants underwent individual dermoscopic imaging of clinically melanoma. All lesions were excised, and histopathological examination was performed on all specimens.

RESULTS

Drawing on histopathological analysis, lentigo maligna melanoma or lentigo maligna was diagnosed in 60 lesions, superficial spreading melanoma in 18, nodular in 10, desmoplastic in 8, superficial spreading melanoma in situ in 12. The most frequent location for head and neck melanoma was the cheek (60 patients, 55.6%). Eight prominent dermatoscopic features were observed in facial melanoma: annular-granular pattern (18%); rhomboidal structures (29%); pseudonetwork (29%); asymmetrical, pigmented, follicular openings (51%); obliterated hair follicles (8%); red rhomboidal structures (18%); increased density of the vascular network (32%); scar-like depigmentation (59%).

CONCLUSIONS

HNM has specific dermoscopic features, and classical extrafacial dermoscopic rules are less useful for diagnosis of facial melanoma. In our study, further characteristic dermatoscopic findings were detected in facial melanoma such as low frequencies of irregular dots, 2 or fewer colors in lesions, the presence of pseudonetwork, increased density of the vascular network, red rhomboidal structures, in addition to dermatoscopic findings of extrafacial melanoma. Thus, it is concluded that the prediction and identification of HNM may be evident with the help of these signs.     

Diagnosis and management of facial pigmented macules

The differential diagnosis of pigmented macules on the mottled chronic sun-damaged skin of the face is challenging and includes lentigo maligna (LM), pigmented actinic (solar) keratosis, solar lentigo, and lichen-planus-like keratosis. Although dermatoscopy improves the diagnostic accuracy of the unaided eye, the accurate diagnosis and management of pigmented facial macules remains one of the most challenging scenarios in daily practice. This is related to the fact that pigmented actinic (solar) keratosis, lichen-planus-like keratosis, and LM may reveal overlapping criteria, making their differential diagnosis clinically difficult. For this reason, practical rules have been introduced, which should help to minimize the risk for inappropriate diagnosis and management of LM.     

A new dermoscopic algorithm for the differential diagnosis of facial lentigo maligna and pigmented actinic keratosis

Background

The clinical and dermoscopic diagnosis of facial lentigo maligna (LM) and pigmented actinic keratosis (PAK) remains challenging, particularly at the early disease stages.

Objectives

To identify dermoscopic criteria that might be useful to differentiate LM from PAK, and to elaborate and validate an automated diagnostic algorithm for facial LM/PAK.

Materials & Methods

We performed a retrospective multicentre study to evaluate dermoscopic images of histologically-proven LM and PAK, and assess previously described dermoscopic criteria.

Results

In the first part of the study, 61 cases of LM and 74 PAK were examined and a parsimonious algorithm was elaborated using stepwise discriminant analysis. The following eight dermoscopic criteria achieved the greatest discriminative power: (1) light brown colour; (2) a structureless zone, varying in colour from brown to brown/tan, to black; (3) in-focus, discontinuous brown lines; (4) incomplete brown or grey circles; (5) a structureless brown or black zone, obscuring the hair follicles; (6) a brown (tan), eccentric, structureless zone; (7) a blue structureless zone; and (8) scales. The newly developed algorithm was subsequently validated using an additional series of 110LMand 75 PAKcases. Diagnostic accuracy was 86.5% (k: 0.73, 95% CI: 0.63-0.83). For the diagnosis of LM vs PAK, sensitivity was 82.7% (95% CI: 75.7-89.8%), specificity was 92.0% (95% CI: 85.9-98.1%), positive predictive value was 93.8% (95% CI: 89.0-98.6%), and negative predictive value was 78.4% (95% CI: 68.4-86.5%).

Conclusions

This algorithm may represent an additional tool for clinicians to distinguish between facial LM and PAK.

     

Dermatoscopic features of extrafacial lentigo maligna

The dermatoscopic features of classic lentigo maligna (LM) are well described; however, there is little literature available on extrafacial LM, which is a less frequently reported condition. The skin architecture is especially rich in adnexae on sun‐exposed areas such as the face, relative to other parts of the body, thus it is possible that the dermatoscopic findings of extrafacial LM will differ from the usual findings of LM. We carried out a dermatoscopic study on three patients with extrafacial LM. The dermatoscopic patterns reflected the underlying histological features of the disease, with increased melanocytes seen along the rete ridges and around follicular ostia, which result in a unique pigment network architecture.     

Reflectance confocal microscopy of facial lentigo maligna and lentigo maligna melanoma: a preliminary study

Background Facial lentigo maligna (LM) and lentigo maligna melanoma (LMM) may be difficult to diagnose clinically and dermoscopically. Reflectance confocal microscopy (RCM) enables the in vivo assessment of equivocal skin lesions at a cellular level. Objectives To assess cytomorphological and architectural RCM features of facial LM/LMM. Methods Four women and eight men aged 58–88 years presenting with facial skin lesions suspicious of LM/LMM were included. In total, 17 lesion areas were imaged by RCM before biopsy. The histopathological diagnosis of LM was made in 15 areas; the other two were diagnosed as early LMM. Results A focal increase of atypical melanocytes and nests surrounding adnexal openings, sheets of mainly dendritic melanocytes, cord‐like rete ridges at the dermoepidermal junction (DEJ) and an infiltration of adnexal structures by atypical melanocytes were found to be characteristic RCM features of facial LM/LMM. Areas with a focal increase of atypical melanocytes and nests surrounding adnexal openings were observed at the basal layer in three cases. The remaining cases displayed these changes at suprabasal layers above sheets of mainly dendritic melanocytes. Cord‐like rete ridges at the DEJ and an infiltration of adnexal structures by atypical melanocytes were observed in all cases. Previously described criteria for RCM diagnosis of melanoma, such as epidermal disarray, pleomorphism of melanocytes and pagetoid spreading of atypical melanocytes, were additionally observed. Conclusions We observed a reproducible set of RCM criteria in this case series of facial LM/LMM.     

Correlation between the dermatoscopic and histopathological features of pigmented basal cell carcinoma

Background Dermatoscopy has a great value in the diagnosis of pigmented basal cell carcinoma (BCC), which is a clinical variant of BCC. The precise definitions of histopathological correlates of dermatoscopic features observed in pigmented BCC have not been established yet. Objective The present study aimed to investigate the correlation between the dermatoscopic features of pigmented BCC and their histopathological counterparts to provide clear histopathological definitions of each dermatoscopic feature. Methods In this case series that comprised a methodological component, after the orientation of dermatoscopic features was determined by placing sutures in the lesions, the histopathological counterparts of each were examined and definitions were made accordingly. Results Although the most common histopathological subtype of BCC is the solid type, the most common histopathological subtype observed in the pigmented BCC lesions in the present study was the superficial multifocal type (72.5%). Blue‐whitish veil was observed in 57.5% (n = 23) of the lesions, a percentage higher than that reported in the literature. In addition to confirming the previously histopathologically defined dermatoscopic features of pigmented BCC, we identified three histopathologically undefined features of pigmented BCC that are spoke‐wheel areas, large blue‐grey ovoid nests and multiple blue‐grey globules. Conclusion Dermatoscopy facilitates prediction of the corresponding histopathological findings in pigmented BCC, based on specific dermatoscopic features.     

Use of digital epiluminescence microscopy to help define the edge of lentigo maligna

OBJECTIVE: To compare identification of the border of lentigo maligna (LM) with digital epiluminescence microscopy (DELM) with clinical and Wood light assessment. DESIGN: The borders of lesions identified clinically with the Wood light, with DELM, and after excision by Mohs micrographic surgery were traced onto plastic sheets. The borders defined on the tracings were compared for congruence and mean surface area. SETTING: Cardinal Bernardin Cancer Center for Skin Cancer, Loyola University Health System, Maywood, Ill. PATIENTS: Twenty-six consecutive patients with LM of the head and neck. MAIN OUTCOME MEASURES: Results of the comparison of the outlines of the borders and the mean surface area identified by the 4 methods. RESULTS: The border determined by clinical examination was smaller than that determined with the Wood lamp or by DELM. Most lesions underwent an additional excision 5 mm beyond the DELM-defined border. The DELM pattern of LM with asymmetric follicular openings and dark brown rhomboidal structures changed at the periphery and became a pigmented thin mesh that was associated with the histopathological features of melanoma in situ. More homogeneous pigmented areas extending from the LM were associated with the pathologic features of melanocytic hyperplasia. CONCLUSIONS: Visualization of LM by DELM (dermoscopy) helps to guide resection. Because LM arises in sun-damaged skin with melanocytic hyperplasia, determining the tumor-free margin requires the judgment of an experienced physician.     

Melanocytic soluble adenylyl cyclase protein expression around lentigo maligna and in contralateral control skin

Recurrence rates of both lentigo maligna (LM) and lentigo maligna melanoma (LMM) following conventional surgery are usually relatively high. We aimed to assess the frequencies of melanocytes in tumour‐free margins around LM/LMM using soluble adenylyl cyclase (sAC) immunohistochemistry, and to compare these with those of matched healthy contralateral skin. Using the primary mouse‐anti‐human sAC antibody R21, we evaluated pan‐nuclear melanocytic R21 immunostaining, and found that it was significantly (P < 0.001) higher in peritumoural melanocytes (median 20%; range 0–100%) than in contralateral healthy skin (mean 0%; range 0–20%). Accordingly, there was no correlation between peritumoural and contralateral R21 immunoreactivity (r = 0.12; P = 0.18). In conclusion, melanocytic R21 immunoreactivity in melanocytes is higher in tumour‐free margins around LM/LMM than in site‐matched contralateral skin. This observation may indicate that the biology of ‘healthy’‐appearing melanocytes around LM/LMM might be different from that of truly benign melanocytes.     

A retrospective study of 150 patients with lentigo maligna and lentigo maligna melanoma and the efficacy of radiotherapy using Grenz or soft X-rays

BACKGROUND: Lentigo maligna (LM) and lentigo maligna melanoma (LMM) are the most common melanocytic neoplasms on sun-exposed skin of elderly patients. OBJECTIVES: To perform a retrospective study of 150 patients with LM and LMM treated with radiotherapy using Grenz or soft X-rays. METHODS: The information recorded and analysed included gender, age, diagnosis, size of the lesion, localization, X-ray treatment, recurrence rate, other skin malignancies and non-dermatological neoplasms. RESULTS: The 150 patients comprised 78 women and 72 men (mean age 70 years). Ninety-three patients had LM, 54 had LMM and three had both neoplasms. Ninety per cent of lesions were located on the face. Treatment was with Grenz rays in 96 patients with LM and 11 with LMM (70%) and with soft X-rays in 46 patients with LMM (30%). Three patients were treated using both modalities. One hundred and one patients were followed up for at least 2 years after radiotherapy (mean 8 years). The mean time to recurrence was 45.6 months, and the recurrence rate was 7% (seven of 101). Other skin malignancies were observed in 65 of 150 patients, including basal cell carcinoma in 23 (35%) and actinic keratosis in 20 (31%). Four patients developed internal cancers. CONCLUSIONS: The study showed that radiotherapy of LM and LMM was curative. In particular, radiotherapy proved to be an excellent treatment for elderly patients. Owing to the high incidence of other skin cancers, LM patients need careful follow-up.     

Dermoscopic pattern of intermediate stage in seborrhoeic keratosis regressing to lichenoid keratosis: report of 24 cases

BACKGROUND: Lichenoid keratosis (LK) is a well-described entity which has been proposed to represent an immunological or regressive response to pre-existing epidermal lesions such as solar lentigines or seborrhoeic keratoses. OBJECTIVES: To evaluate the dermoscopic criteria of a series of cases of LK with remaining areas of seborrhoeic keratosis which were both dermoscopically and histologically diagnosed. METHODS: Pigmented lesions with dermoscopic areas of seborrhoeic keratosis and LK in the same tumour were consecutively diagnosed and prospectively included in the study. All pigmented lesions were examined and registered using DermLite Foto equipment (3Gen, LLC, Dana Point, CA, U.S.A.), at 10-fold magnification, at the Dermatology Department of Hospital de Sant Pau i Santa Tecla (Tarragona, Spain), between 1 January 2003 and 31 December 2005. RESULTS: In total, 24 cases of lesions with dermoscopic areas of seborrhoeic keratosis and LK were collected. In four lesions (17%), the clinical differential diagnosis without dermoscopy included malignant melanoma and in seven lesions (29%), basal cell carcinoma. The diagnosis of LK was clinically considered without dermoscopy in only six cases (25%). A granular pattern was observed to be distributed throughout the LK areas of the lesions. This pattern consisted of the presence of brownish-grey, bluish-grey or whitish-grey coarse granules that formed, in 11 cases (46%), globules and/or short lines. In one lesion, located on the face, these short lines produced annular or rhomboid structures as seen in lentigo maligna melanoma. CONCLUSIONS: Dermoscopy is a useful tool which assists in the correct clinical recognition of LK, which may also potentially illuminate the pathogenesis of these tumours, showing the intermediate stage of regressing epidermal lesions in an LK.     

Superficial dermal melanocytosis of the elderly: An exceptional occurrence?

The development of flat pigmented lesions on chronically sun-damaged (CSD) skin of the face may represent the clinical manifestation of a wide variety of hyperplastic/neoplastic melanocytic proliferations. We report the exceptional case of an acquired pigmented patch occurring on CSD skin, histopathologically characterized by diffuse hyperplasia of dendritic/spindled melanocytes in the superficial dermis within a widened band of actinic elastosis. This lesion was associated with a small focus of early invasive lentigo maligna melanoma (LMM). We show the melanocytic nature of the population of dermal pigmented cells by means of single and double immunohistochemical staining for melanocytic and histiocytic markers. The biologic significance of the focus of LMM within the hyperpigmented lesion (whether random collision phenomenon or causally related occurrence), as well as the pathogenesis of the whole dermal lesion are difficult to elucidate. Our case emphasizes the need for a better understanding of the pathophysiology of so-called dermal melanocytes.