Concomitant traumas influence prognosis in melanomas of the nail apparatus*

From Keratoma to Anaplastic Malignant Melanoma in a Horse's Hoof

Melanomas in horses are most often associated with gray, older horses with an average age of over 16 years. Anaplastic malignant melanoma, however, can very rarely affect non-gray horses. Herein, we report a case of a 16-year-old Wielkopolski gelding with a chronic lameness caused by a mass in the hoof. The first resection of the lesion and histopathological examination confirmed the presence of a keratoma. The regrown mass and persistent lameness resulted in another mass resection. The second histopathological examination result suggested a neoplastic growth of melanocytic origin with a low histological malignancy. Less than 2 years after the first resection, the horse returned to the clinic with deformation of the hoof capsule and severe lameness. The result of the third histopathological examination indicated low-differentiated malignant neoplasm. The result of the immunohistochemically test indicates a tumor of melanocytic origin with high malignancy.

Clinical features, molecular pathology, and immune microenvironmental characteristics of acral melanoma

Acral melanoma (AM) has unique biology as an aggressive subtype of melanoma. It is a common subtype of melanoma in races with darker skin tones usually diagnosed at a later stage, thereby presenting a worse prognosis compared to cutaneous melanoma. The pathogenesis of acral melanoma differs from cutaneous melanoma, and trauma promotes its development. Compared to cutaneous melanomas, acral melanomas have a significantly lighter mutational burden with more copy number variants. Most acral melanomas are classified as triple wild-type. In contrast to cutaneous melanomas, acral melanomas have a suppressive immune microenvironment. Herein, we reviewed the clinical features, genetic variants, and immune microenvironmental characteristics of limbic melanomas to summarise their unique features.

Different progression pattern between acral and nonacral melanoma: A retrospective, comparative, clinicoprognostic study of 492 cases of primary cutaneous melanoma according to tumor site

BACKGROUND

There are limited data regarding the difference in progression pattern between acral melanoma and nonacral melanoma.

AIMS

The objectives of this study were to compare the progression pattern between acral and nonacral melanoma and evaluate its impact on clinical outcomes.

METHODS

Clinical and histopathological features, survival outcomes and prognostic factors of 492 patients with acral melanoma or nonacral melanoma were retrospectively evaluated using the Asan Medical Center database.

RESULTS

The male-to-female ratio and the mean age was 1:0.92 and 60.2 years for acral melanoma (n = 249), and 1:0.85 and 58.4 years for nonacral melanoma (n = 243), respectively. The demographic difference was not significant. Although prediagnosis duration was longer and the advanced stage was more common in acral melanoma than that in nonacral melanoma, the vertical growth phase was more common in nonacral melanoma than that in acral melanoma, whereas, the horizontal diameter is longer in acral melanoma than that in nonacral melanoma. Dissemination to lymph nodes was more common in acral melanoma than that in nonacral melanoma. Lymph node involvement was associated with deeper Breslow thickness in nonacral melanoma but not in acral melanoma. The degree of correlation of prediagnosis duration with horizontal diameter was remarkable in acral melanoma, but with Breslow thickness in nonacral melanoma. Overall survival was worse in acral melanoma than that in nonacral melanoma. The prognostic value of Breslow thickness was more remarkable in nonacral melanoma than that in acral melanoma.

LIMITATIONS

This study is a retrospective, single-center design.

CONCLUSION

Acral melanoma has a longer radial growth phase compared with nonacral melanoma. However, acral melanoma is commonly associated with lymph node dissemination which contributed to worse survival in acral melanoma than nonacral melanoma.

Clinical characteristics and prognosis of acral lentiginous melanoma: a single-center series of 211 cases in China

BACKGROUND

Acral lentiginous melanoma (ALM) is common in China with poor prognosis. However, there are only a few studies of ALM in the Asian population. We aimed to summarize and analyze the clinical characteristics, treatment strategy, treatment effect, and prognostic factors of ALM in a Chinese population.

METHODS

We included a total of 249 ALM patients (211 with follow-up data) from a single institution. Demographic, laboratory data, treatment strategy, and prognosis were analyzed.

RESULTS

The ratio of male and female was 1.3 ∶ 1.0. The median age was 58 years old. The majority of patients (70.3%) had lesions on the sole. Trauma history and irritation were associated with lesion size increase in some patients. The prognosis of patients in stage II-III undergoing standard operation was significantly better compared with those without surgical treatment. Patients who did not receive postoperative adjuvant treatment had shorter time to distant metastasis. In multivariable analysis, distant metastasis, duration of disease, LDH level, and Ki67 index were independently associated with survival.

CONCLUSIONS

Prognosis for ALM patients was poor in our study. Distant metastasis, duration of disease, LDH level, and Ki67 index were independently associated with prognosis.

Frequency of Trauma, Physical Stress, and Occupation in Acral Melanoma: Analysis of 313 Acral Melanoma Patients in Korea

Background

Traumatic events are thought to be a cause of acral melanoma. However, little is known about the role of mechanical trauma or physical stress in the development of acral melanoma.

Objective

In our study, we evaluated the frequency of trauma, physical stress, and occupation in patients with acral melanoma and aimed to identify any pathological correlates of these factors.

Methods

We conducted a retrospective study of 313 acral melanoma patients from Chonnam National University Hospital. We mapped melanoma-developed anatomical sites of acral areas and assessed patients' history of trauma, physical stress, and occupation.

Results

Among the 313 acral melanoma patients, many reported a traumatic event (84 of 313; 26.8%) or physical stress (91 of 313; 29.1%) before the melanoma developed. The most common anatomical sites in these patients were on the borders of the foot (136 of 313; 43.5%). Trauma was more commonly associated with the fingernails and toenails than other sites. The frequency of each type of physical stress depended on the site of the lesion. Farmer and fisherman were the most common occupations (130 of 313; 41.5%) of the acral melanoma patients.

Conclusion

Our results demonstrate that traumatic events, physical stress, and certain occupations are common in acral melanomas. Further studies are needed to establish whether these are risk factors for acral melanomas.

Lymphatic invasion in acral and non-acral melanoma: a comparative, clinicoprognostic study of primary cutaneous melanoma according to tumour site

There have been limited studies comparing the clinical significance of lymphatic invasion in melanoma according to tumour site. The objective of this study was to evaluate the impact of lymphatic invasion on the clinicoprognostic features of acral and non-acral melanoma. Clinical and histopathological features and survival outcomes of 532 patients with acral melanoma or non-acral melanoma in the database of the Asan Medical Center, Korea, were retrospectively evaluated according to the presence of lymphatic invasion. Lymphatic invasion was significantly more common in acral melanoma than non-acral melanoma. In acral melanoma, lymphatic invasion was significantly associated with a higher frequency of lymph node involvement and advanced stages, but not associated with Breslow thickness or visceral dissemination. By contrast, lymphatic invasion in non-acral melanoma was significantly associated with a higher rate of visceral involvement, deeper Breslow thickness, as well as a higher rate of lymph node involvement and advanced stages. When acral melanoma and non-acral melanoma both with lymphatic invasion were compared, Breslow thickness was significantly shallower and vertical growth phase was significantly less common in acral melanoma. Meanwhile, visceral involvement was significantly more frequent in non-acral melanoma than acral melanoma. In conclusion, lymphatic invasion was more common in acral melanoma than non-acral melanoma and occurred in acral melanoma cases with relatively thin Breslow thickness, suggesting acral melanoma is lymphotropic.

Acral Melanoma in Chinese: A Clinicopathological and Prognostic Study of 142 cases

Acral melanoma (AM), as a peculiar subgroup of melanoma, is rare in Caucasians but has higher incidence in Asians. Large series of study on AM with clinicopathological features and prognostic factors is still limited, especially in Asian population. We retrospectively collected clinical, pathological and follow-up data of 142 AM cases. All patients were Chinese, with the age ranging from 24 to 87 years (mean 62.0; median 62.0). The Breslow thickness of primary lesions ranged from 0.6 to 16.3 mm (mean 4.9; median 3.7). 85.9% of the patients had acral lentiginous histologic subtype. Plantar was the most frequently involved site, followed by heels. Statistically, duration of the lesion before diagnosis (≤2.5 years), Breslow thickness >4.0 mm (T4), high mitotic index (>15 mm⁻²), presence of vascular invasion, regional lymph node metastasis at diagnosis and pathologic stage (II/III/IV) were found to be independent prognostic factors in both univariate and multivariate analyses. The prognosis of AM in Chinese is extremely poor. Our 5- and 10-year disease-specific survival (DSS) rates were 53.3% and 27.4%, respectively. Therefore, AM in Asians represents a more biologically aggressive melanoma subtype and is thought to carry a worse prognosis when compared with other races or cutaneous melanomas in other anatomic sites.

Dispelling myths concerning pigmented skin lesions

The history of medicine is replete with examples of debunked myths, and in daily clinical dermatological practice, we must still counter many misconceptions regarding pigmented lesions, both with patients and other medical practitioners. Debunking myths and attempting to explain the reasons for these erroneous beliefs are the purposes of this review. The literature review has been partially guided by the results obtained from an online questionnaire conducted on an Italian website (www.vediamocichiara.it) from February 15, 2015 to March 15, 2015. The remaining discussed were selected on the basis of the existing literature and our personal experience. In order to explore these misconceptions, the following are the seven most salient questions that require investigation: (i) Is it dangerous to excise moles?; (ii) Is it dangerous to traumatize moles?; (iii) Are plantar moles worrisome?; (iv) Is it necessary to selectively apply sunscreen to moles?; (v) Is it inadvisable to partially biopsy a melanoma?; (vi) Do moles turn into melanoma?; and (vii) Is it necessary to perform sentinel lymph node biopsy for thin melanomas and for atypical Spitz naevi? Myths are ubiquitous, being prevalent in dermatological practice, with many of them concerning pigmented skin lesions. By encouraging critical analysis by patients and medical practitioners, the birth and perpetuation of myths can potentially be minimized, for the ultimate benefit of patients. This requires a scientific approach to be rigorously applied to dermatology, with critical questioning of unsubstantiated hypotheses including those emanating from the mass media as well as from respected sources.

Melanoma: Clinical Presentations

The malignant cell in melanoma is the melanocyte. Because melanocytes are located in the basal layer of the epidermis, melanoma is most commonly seen on the skin. However, melanoma can also arise on mucosal surfaces such as the oral cavity, the upper gastrointestinal mucosa, the genital mucosa, as well as the uveal tract of the eye and leptomeninges. Melanomas tend to be pigmented but can also present as pink or red lesions. They can mimic benign or other malignant skin lesions. This chapter presents the spectrum of typical and less typical presentations of melanoma, as well as patterns of spread. It is divided into (1) cutaneous lesions; (2) patterns of regional spread, (3) non-cutaneous lesions; and (4) distant metastases.

Prognosis of acral melanoma: a series of 281 patients

BACKGROUND

Acral melanoma (AM) is an unusual malignancy with poor survival. This study defines a cohort of patients, treated at a single institution, and the factors associated with survival and comparison with nonacral cutaneous melanoma (NACM).

METHODS

All patients with AM presenting from 1995 to 2010 were identified from a prospectively maintained database. Analysis of clinicopathologic features of AM associated with disease-specific survival (DSS) was performed. A stratified, stage-matched survival analysis compared the outcome of 281 acral to 843 extremity NACM patients.

RESULTS

A total of 281 AM patients (170 volar, 111 subungual) were identified. Pathologic stage (p < 0.001), ulceration (p < 0.001), Breslow thickness (p < 0.001), and a positive sentinel lymph node (p < 0.001) were found to be poor prognostic indicators associated with DSS. In stage-matched analysis, AM had a worse DSS compared with NACM (hazard ratio 1.8; 95 % CI 1.2-2.7; p < 0.01).

CONCLUSIONS

This study represents the largest, single-institution series describing the characteristics and outcomes of AM. AM tumors exhibit aggressive histopathologic features associated with a poorer survival outcome. AM patients have an inferior survival than extremity NACM when matched for stage, perhaps reflecting inherent alterations in tumor biology. This warrants further investigation into the differences between acral and cutaneous melanoma.

Nail apparatus melanoma: is trauma a coincidence? Is this peculiar tumor a real acral melanoma?

Nail Apparatus Melanoma (NAM) is rare, particularly in Caucasians. Understanding its pathogenesis and collecting epidemiologic data may be difficult due to its location and the exiguity of the case series of this cancer. Cutaneous melanoma has been thought related to UV radiation, and NAM is considered an acral variant of melanoma, even if the nail presents a specific anatomy. Little is reported about pathogenesis, except reports suggesting traumatic injuries as a causal factor. UV exposure is debated in nail melanoma because of its structure. The nail is, in fact, a unique structure with sun-exposed and non exposed melanocytes. NAM arises from the nail melanocytes, located in the nail matrix, which is the germinative part of the nail and composed of a proximal and distal portion. The proximal nail matrix lays under the proximal nail fold that covers it and is non-sun exposed, while the distant nail matrix, clinically visible as the lunula, is sun-exposed, though lying underneath the nail plate. According to these anatomical data, NAM is a distinct melanoma type, and studies need to classify it as acral melanoma or as a particular type of melanoma with its own pathogenesis and prognostic criteria. This study investigates potential risk factors of NAM, emphasizing (i) trauma and (ii) UV exposure among our NAM patients.

The association between trauma and melanoma in the Chinese population: a retrospective study

BACKGROUND

The association between trauma and melanoma has been a controversial issue.

OBJECTIVES

To analyse the profiles of melanoma, and to determine whether trauma is associated with development of acral melanoma in the Chinese population.

PATIENTS AND METHODS

Retrospective analysis of 685 cases of cutaneous melanoma in the dermatology departments of Xijing Hospital in northwestern China and Xinan Hospital in southwestern China from 1982 to 2011.

RESULTS

Of the 685 patients included in the study, 437 (63.8%) suffered from melanoma on the extremities. A total of 104 patients (15.2%) exhibited an association between trauma and melanoma. The primary anatomic sites of the tumours were the upper extremities (17, 16.3%), lower extremities (74, 71.2%) and other sites (13, 12.5%). Among these cases, the extremities were with remarkably higher risks of post-trauma melanoma than the other sites [adjusted odds ratio (OR) 3.968; 95% confidence interval (CI) 2.267-5.592]. Notably, patients in the south part of China were with a stronger risk of post-trauma melanoma on the lower extremities than those in the north (adjusted OR 1.764; 95% CI 1.192-2.666) part. In addition, a significant higher risk of post-trauma melanoma on the extremities was observed in the male gender (adjusted OR 1.848; 95% CI 1.186-2.887).

CONCLUSIONS

Our findings provide epidemiological evidence for a potential association between traumatic events and melanoma of the extremities, especially the lower limbs, where a history of trauma is more likely.

Epibulbar melanoma in a foal

A case of epibulbar melanoma in a 6-month-old, gelded, chestnut Hanoverian foal is reported. The location and clinical appearance upon initial presentation led to the tentative diagnosis of staphyloma or a congenital mass of unknown origin. An attempt was made to surgically excise the mass under general anesthesia, but due to its infiltrative nature and intraoperative appearance, most, but not all was removed without compromising the integrity of the globe. Histopathological evaluation revealed a multinodular to packeted, poorly demarcated, unencapsulated, infiltrative exophytic melanocytic neoplasm composed of bundles and nests of plump spindloid to polygonal heavily pigmented epithelioid neoplastic cells interspersed with pigment-laden macrophages within a fine fibrovascular stroma. Upon examination after enucleation, neoplastic cells were found to infiltrate into the lateral cornea, sclera and the choroid. This is a unique case of an epibulbar melanoma with choroidal invasion in a foal. Based on the sudden onset and rapid growth as well as the histological evidence of invasion, well-differentiated features, heavy pigmentation, and no apparent mitoses, this neoplasm was considered to be a low-grade malignant melanoma. At 14 months after excision there is no evidence of recurrence.

Updates from the British Association of Dermatologists 86th Annual Meeting, 4?7 July 2006, Manchester, U.K

Here we provide a synopsis of the main clinical and research advances in clinical, epidemiological and biological dermatology that were presented at the meeting of the British Association of Dermatologists (BAD) held during 4-7 July 2006, in Manchester, U.K. Only the more important advances or summaries of findings are mentioned. The meeting was held at the Manchester International Conference Centre (Fig. 1). The annual dinner was held at Manchester Town Hall, in the Great Hall decorated with magnificent murals by Ford Madox Brown, with Dr Susan Burge as host.

Clinical pathologic correlations for diagnosis and treatment of nail disorders

Clinicopathologic correlation is crucial to the correct diagnosis of disorders of the nail unit. This chapter will explore four common clinical scenarios and how pathology can help differentiate between their various etiologies. These include: dark spot on the nail plate (melanin versus heme), subungual hyperkeratosis (onychomycosis versus psoriasis), longitudinal melanonychia (benign versus malignant), and verrucous papule (verruca versus squamous cell carcinoma). Consideration must be given to both when to perform a biopsy and the location of the biopsy site, which must be based on an understanding of the origin of the changes. An overarching principle is that lesions within the same differential diagnosis may be present concomitantly, such as malignant melanoma of the nail unit associated with hemorrhage. Therefore, even with a biopsy-proven diagnosis, the clinician must always monitor lesions of the nail unit for appropriate response to treatment and consider an additional biopsy for recalcitrant lesions.