Role of obesity on the thickness of primary cutaneous melanoma

BACKGROUND

Thick primary cutaneous melanoma (PCM) is associated with older age, male sex, being single, a low educational level, self-detection and general practice detection, nodular melanoma (NM) and acral lentiginous melanoma (ALM) types; and are found in the head-neck and lower limb locations. Obesity plays a direct role on melanoma tumour growth, as it has been shown in animal models, but its role in the thickness of PCM remains unknown.

OBJECTIVES

We investigated the impact of obesity on the thickness of invasive PCM.

METHODS

A cross-sectional study was performed in a prospective cohort for which we collected several clinical and histological data already known to be associated with thick PCM and the Body Mass Index from new cases of invasive PCM which were referred to the dermatology department in Valence.

RESULTS

Four hundred and twenty-seven patients were studied. In an univariate analysis, thick PCM was associated with low educational level, obesity, identification by the patient or the general practitioner (GP), location on the cephalic extremity, in a non-visible area of the body, the NM and ALM type, and an ulceration. In a multivariate analysis, NM, ulceration, topography of the melanoma and identification of the melanoma by the patient or GP were significantly associated with thick melanoma. When including only clinical features in the model, low educational level, mode of melanoma identification and obesity were significantly associated with a risk of thick melanoma.

CONCLUSIONS

Obesity is a clinical independent risk factor of thick PCM. For health policies, governments should pay greater attention to detect melanoma in obese patients. Our results encourage the basic research on tumoural growth mechanisms due to obesity in melanoma.

CD20 antigen may be expressed by reactive or lymphomatous cells of transformed mycosis fungoides: diagnostic and prognostic impact

Mycosis fungoides (MF), the most common primitive cutaneous T-cell lymphoma, can undergo transformation in about 10% of cases. Transformed mycosis fungoides (T-MF) is often associated with the appearance of a CD20 component. The aim of this study was to analyze whether such cells are reactive or lymphomatous and to evaluate their prognostic impact. Among 311 T-MFs from the French Cutaneous Lymphoma Study Group registry, we studied 148 cases. CD20 was expressed in 88 cases (59%). The proportion of CD20 cells among T-MF lesions was <10% for 54 cases (38%), 10% to 49% for 71 cases (81%), and >50% for 17 cases (19%). We focused the study on 23 cases that contained >50% CD20 cells. To evaluate the nature of the CD20 component, we used immunohistochemistry (2 anti-CD20 antibodies, L26 and 7D1 clones, and 2 other anti-B-cell antigen antibodies, CD22 and PAX5) and a double-stain immunofluorescence technique (anti-CD20 and anti-CD3 antibodies). The clonality of B cells was studied by polymerase chain reaction. Three profiles were observed. In 15 of the 23 cases, the CD20 cells were reactive. In 6 cases, CD20 protein was aberrantly expressed in T-MF lesions. Lastly, there were 2 composite lymphomas (T-MF infiltrate with a B-cell follicular lymphoma). In view of this series, we propose a simple algorithm to help pathologists evaluate the nature of the CD20 component associated with T-MF. Although statistically not significant, there was a trend toward a worse prognosis in the presence of >50% CD20 cells and of a nodular perifollicular pattern of this component.

[Primary eccrine porocarcinoma: a clinicopathological study of 50 cases]

BACKGROUND

Eccrine porocarcinoma is a rare cutaneous tumor arising from the intra-epidermal portion of eccrine sweat glands, the acrosyringium. Histoprognostic studies in large series are rare. Herein, we report a retrospective study of 50 cases.

PATIENTS AND METHODS

Fifty cases of porocarcinoma were retrieved from a histopathological register. Each histopathological sample was evaluated for the following criteria: presence or absence of dermal invasion, pattern of the infiltrative component (pushing or infiltrative), tumor thickness, lymphovascular emboli, perineural invasion and mitotic index. Clinical data and outcome were also retrieved for each patient.

RESULTS

Mean patient age was 77 years (range: 43-99 years). The mean duration of progression prior to diagnosis was 4 years and 5 months. The 2 most common skin locations were the head (38%) and lower limbs (20%). The lesions showed no specific distinctive clinical features. Six cases were in situ, and 44 were invasive (23 with limited infiltration and 20 with scattered infiltration). Mean tumor thickness was 4.37 mm (range: 0.5 to 20 mm). Neighboring or remote epidermal involvement was noted in 7 cases. Lymphovascular emboli were observed in 3 cases. No cases of neurotropism were observed. The average mitotic index was 6.5 mitoses/high power (×400) field. A mean follow-up of 24.3 months was available for 48 patients. Local recurrence was noted in 5 patients, 4 of whom died from visceral metastases. These 5 cases showed no distinctive clinical features, a scattered pattern of the invasive component, cuticular cells, significant tumor thickness (mean 12.8 mm, range 9-20 mm), and an elevated mitotic index. Two histopathological criteria were significantly associated with a metastatic outcome: scattered pattern of the dermal invasive component (P=0.04) and significant tumor thickness, above 10mm (P<0.01).

CONCLUSION

Porocarcinoma is a tumor without any particular clinical criteria to distinguish it from squamous cell carcinoma. The architecture of the invasive component and tumor thickness constitute 2 important histoprognostic criteria.

Melanoma patients under vemurafenib: prospective follow-up of melanocytic lesions by digital dermoscopy

Second primary melanomas (SPMs) induced by vemurafenib have been recently described. The aim of this study was to define the dermoscopical signs of melanoma in this context. Patients underwent a total body examination before receiving vemurafenib. Each single melanocytic lesion was registered before therapy by digital dermoscopy (DD), and then repeated monthly until therapy disruption. Forty-two patients were included, the mean duration of follow-up was 6.7 months, and a mean number of 51 lesions per patients were captured and followed. A total number of 2,155 lesions were recorded, of which 56.1% presented at least one change during the study. More common changes concerned the color of the lesions (up to 15%) and appearance or disappearance of globules (14.6%). Thirty-six of the melanocytic lesions were surgically excised, 21 were classified as a nevus, 1 was a lentigo, and 14 as a second new primary melanoma (occurring in 21% of our patients). DD allowed us to excise only 36/2,155 (1.6%) of the lesions and permitted us to detect 14 SPM in the 42 patients with a highly efficient malignant/benign ratio of 63.6%. Although vemurafenib is now tested in an adjuvant setting DD should be systematically used in order to accurately detect SPM and reduce the number of unnecessary excisions.

Linear atrophoderma of moulin: report of 4 cases and 20th anniversary case review

BACKGROUND

Linear atrophoderma of Moulin (LAM) is a rare clinical entity which was first described by Moulin et al. in 1992. The diagnosis is clinical, characterized by acquired unilateral hyperpigmented, depressed band-like skin lesions following Blaschko's lines. The disease typically affects children or adolescents and has a good prognosis without evidence of long-term progression. To date, the pathophysiology is unclear. Different authors hypothesize that the disease is secondary to a mosaic manifestation as a result of a post-zygotic mutational event.

OBSERVATIONS

Four patients (2 men, 2 women) had a history of unilateral band-like skin lesions located on the lower legs (50%) or the trunk (50%). Physical examination showed atrophic and hyperpigmented skin lesions along Blaschko's lines, which appeared during childhood in 3 cases and at the age of 20 in the last case. Lesions had progressed rapidly but seemed to have stabilized so far except for 1 case who presented spontaneous improvement. Histopathological examination revealed a normal epidermis with a hyperpigmented basal layer and a perivascular lymphocytic infiltrate in the dermis.

CONCLUSION

LAM is a rare disease with 32 reported cases and remains an exclusion diagnosis. Since the problem is mainly esthetic, treatments should not be too aggressive.

Metastatic melanoma patients: Prospective follow-up of pigmented lesions under vemurafenib by digital dermoscopy

9093

Background: Vemurafenib is the first approved by the FDA BRAF V600 inhibitor for the treatment of metastatic melanoma. Many cutaneous side-effects such as squamous cell carcinoma, xerosis, photosensitivity are observed. We first reported the occurrence of second primary melanomas (SPM) under BRAF inhibition. These SPM were shown to be wild-type for BRAF. The exact occurrence of these changes is still unknown. We wanted then to explore prospectively the impact of vemurafenib on cutaneous pigmented lesions using sequential digital dermoscopy. Methods: We registered prospectively following inform consent the pigmented lesions of patients under vemurafenib. We examined the total body surface and captured from 9 to 134 pigmented lesions on 24 patients. Each single lesion was followed monthly from vemurafenib initiation to vemurafenib disruption due to disease progression. Dermoscopic modifications of the melanocytic lesions including external diameter, dermoscopical pattern, pigmentation, network thickness, dots distribution and keratosis appearance were analyzed. Results: The median duration of dermoscopic follow up was 6,9 months ( range from 2 to 16 months), 1098 pigmented lesions were included. At least one modification occurred in 56% of the lesions. Most frequent modifications were the occurrence of dark globules (56%), change in the pigmentation coloration (47%), variations in network thickness (32%), increase of the external size (20,1%), onset of black areas (14%), onset of keratosis (4,4%). Up to 5,3% of lesions spontaneously disappeared; 21 excisions were performed due to significant dermoscopic changes and revealed 10 early melanomas in 5/24 patients (20,8%). The 11 remaining lesions were benign. Conclusions: More than fifty percent of the patients under vemurafenib will experiment significant modifications on their pigmented lesions. In our experience 10/21 removed lesions were early melanomas that could not be otherwise diagnosed using naked-eyes examinations only. Digital dermoscopy is one of the tool that can be use to discriminate earlier the modifications. Such careful monitoring will improved the safety when evaluating BRAF inhibitors in adjuvant setting.