Non–pigmented modular plantar melanoma in 12 Japanese patients

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

Background

The 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.

Objectives

To calculate the proportion of ALM among all melanoma subtypes and to determine the frequency of dermoscopic features of ALM in the Turkish population.

Methods

Out 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.

Results

The 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.

Conclusions

ALM 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.

Case series of volar juvenile xanthogranuloma: clinical observation of a peripheral rim of hyperkeratosis

Juvenile xanthogranuloma is a benign histiocytic tumor predominantly occurring in children as yellowish papules on the head and trunk. Presentations on the volar surfaces are rare and may cause diagnostic confusion with pyogenic granuloma, eccrine poroma and digital fibrokeratoma. We report two patients with unusual presentations of solitary juvenile xanthogranuloma on the palm or sole. Both had lesions lacking the classic yellowish color and demonstrating a well-defined, peripheral hyperkeratotic rim. Histopathological evaluation revealed prominent orthokeratosis corresponding to the rim. Additional histological features, including dermal histiocytes and Touton giant cells, were consistent with the diagnosis of juvenile xanthogranuloma. Given the unusual locations and colors of the lesions, we conclude that histopathological evaluation is central to diagnosing volar juvenile xanthogranuloma. We additionally suggest that juvenile xanthogranuloma should be included in the differential diagnoses of volar lesions displaying a peripheral hyperkeratotic rim.

Clinical features of 36 cases of amelanotic melanomas and considerations about the relationship between histologic subtypes and diagnostic delay

BACKGROUND

Amelanotic melanomas (AM) are a difficult diagnostic challenge for clinicians.

OBJECTIVE

To consider the clinical presentation of AM, the histologic subtypes involved, the relationship with the diagnostic delay and the possible involvement in overall prognosis.

PATIENTS/METHODS

Patients who were observed in our department to be affected by cutaneous melanomas were recorded. Sex, age, the clinical features, the site of presentation, the suspected diagnosis, the clinical course, the histological type, the Clark level and the Breslow thickness were recorded. AM were divided in three main clinical types: an erythematous macule or patch on sun-exposed skin, a dermal plaque or nodule without a particular epidermal change, an exophytic nodule. Only pure AM were considered. Histological subtypes considered were superficial spreading melanoma, nodular melanoma, and lentigo maligna melanoma. Diagnostic delay considered from when the patients first noticed the lesion on the site where the melanoma was diagnosed and when the physician or the patient first proposed the removal was recorded. The chi-squared test was used for statistical evaluation with P < 0.05 as level of significance.

RESULTS

Thirty-six cases of AM out of a total of 500 melanomas (7.2%) were collected. The most frequent morphology of clinical presentation was the papulo-nodular form, followed by the plaque form. Mean Breslow thickness of AM was 1.72 mm compared to 0.61 mm of pigmented cases. Nodular histotype was highly represented in AM (30.5% of cases) with respect to pigmented nodular melanomas (2.9%). The diagnostic delay did not differ between amelanotic and pigmented melanomas, nor between nodular AM and nodular pigmented melanomas.

CONCLUSION

The great prevalence of clinical and histological nodular cases, the higher mean Breslow thickness (considered as the most important factor of prognosis) of AM compared with a not significant greater diagnostic delay may point out that a good percentage of AM have an intrinsic faster speed of growth with a worse prognosis irrespectively of the diagnostic performance. The importance of educational campaign for patient and physicians is stressed.

Plantar malignant melanoma -- a challenge for early recognition

The incidence of malignant melanoma has been continuously increasing over the last few decades. Non-plantar melanomas are nowadays usually diagnosed and treated surgically at an early stage. In contrast, melanoma in a plantar location is usually diagnosed at an advanced tumour stage, conferring a poor prognosis. To discover the reasons for this remarkable difference in recognition and prognosis, we analysed our cases of plantar malignant melanoma in a retrospective study. From 1990 to 1997, we treated 925 melanoma patients. Of these, 68 cases (7%) were classified as plantar melanoma. For non-plantar melanoma patients the mean age was 52.6 years, the mean Clark level was 2.8 and the mean tumour depth was 1.22 mm. In contrast, the mean age of patients with plantar melanoma was 63.3 years, the mean Clark level was 3.61 and the mean tumour depth was 2.55 mm. The mean time between the first observation of the plantar skin lesion and the first consultation with a physician (patients' delay) was 4.8 years and, on average, it took an additional 7 months before adequate surgical treatment was performed (physicians' delay). The prognosis of our patients was poor. In 98.5% (n = 67) further metastases were observed on follow-up. Since there is still no cure for advanced plantar malignant melanoma, the early detection and subsequent surgical treatment of plantar melanoma is decisive for the prognosis. Based on our results, the poor survival can be improved by a significant reduction in the time period between the first observation of a plantar skin lesion and surgical treatment. Therefore there is an urgent need for special preventive health care campaigns to reduce significantly both the patients' and the physicians' delay.