Sun-exposed Areas Research Articles

Serum vitamin D level, sun-exposed area, dietary factors, and physical activity as predictors of invasive breast cancer risk among Sudanese women: A case-control study.

Background:The role of vitamin D in the development, progression, and prognosis of breast cancer, though widely studied worldwide, has been inconclusive. This study intended to assess the role of some factors (including serum vitamin D level, sun-exposed area, dietary factors, and physical activity) as predictors of the development of invasive breast cancer (IBC) among Sudanese women.Methods:A case–control study was conducted on 200 Sudanese women (100 with newly diagnosed IBC and 100 matched healthy females). Serum 25-hydroxyvitamin D was measured through a competitive electrochemiluminescence immunoassay. Matching analysis was adopted by R version 3.4.1 making use of the “MatchIt” package for calculating propensity scores to build a confounder-adjusted, multiple generalized, linear logistic regression model.Results:Participants’ age ranged from 28 to 85 years with a mean [±standard deviation (SD)] of 48.10 (±12.11) years. The mean (±SD) serum vitamin D level was 12.97 (±8.60) and 13.79 (±6.79) ng/mL in breast cancer and noncancer Sudanese women, respectively [P = 0.013; odds ratio (OR) 0.862; 95% confidence interval (CI) 0.766–0.969; β = 0.149)]. Sun-exposed area (P = 0.038; OR 0.013; 95% CI 0.000–0.782; β = 4.339) is significantly and negatively associated with breast cancer development. While moderate physical activity (P = 0.0008; OR 2625.430; 95% CI 26.647–258673.001; β = 7.873) is significantly and positively associated with IBC risk. Occasional consumption of milk, dairy products, eggs, and fish reduces the risk of developing IBC by 78.1%, 75.0%, 78.4%, and 76.4%, respectively.Conclusion:The higher the plasma vitamin D level by one unit, the lower the risk of breast cancer by 13.84%. Sedentary lifestyle, reduced sun-exposed skin area, and low serum vitamin D levels can be considered as predictors of IBC. Encouraging moderate physical activity and consumption of certain foods may, in part, decrease the precipitating risks of breast cancer. More studies and research are needed to confirm these findings.

Case for diagnosis. Atypical fibroxanthoma

Atypical fibroxanthoma is a rare superficial fibrohistiocytic tumor. Clinically, it presents itself as a painless, solitary, ulcerated, and slow-growing nodule found mainly on sun-exposed areas - especially of the head and neck - of elderly individuals. The diagnosis is based on histopathological and immunohistochemical features. Immunohistochemical staining plays a critical role for the exclusion of differential diagnoses. Since atypical fibroxanthoma has an indolent clinical course, surgical excision is adequate for treatment. We present a case of atypical fibroxanthoma on the ear of a patient.

Extensive perianal basal cell carcinoma: a case report.

Introduction: Basal cell carcinoma is the most common skin cancer. It usually occurs in sun-exposed areas; perianal location is rare. The extension to the anal canal is exceptional, only a few cases were reported in the literature. Observation: we report the case of a 58 years old patient, referred for a chronic ulceration of the perianal area. Histopathology revealed an extensive basal cell carcinoma. a large excision was performed, with a favorable outcome. conclusion: the main lesson from this case is that although basal cell carcinoma is exceptional in the perianal region, a biopsy is mandatory for all chronic perianal ulcerations.

Ultrasonographic evaluation of maxillofacial swelling in a pediatric patient with Xeroderma pigmentosum

Background/Aim: Xeroderma pigmentosum (XP) is an autosomal recessive skin disease. Affected patients have skin problems, oral mucosa and neurologic symptoms. In these patients, erythematous, hyperpigmented or malignant skin lesions may occur in the sun-exposed areas. Leukoplakia, erythroplakia, and squamous cell carcinoma of the tip of the tongue and lips are common oral lesions associated with XP. Case report: Treatment of the disease included protection from ultraviolet radiation, topical application to treat actinic keratitis, and multidisciplinary approaches by physicians. Conclusions: Even though USG in dentistry is not very common, it is a non-invasive, cost-effective, readily available and repeatable diagnostic imaging method. Thus, USG should take place as a routine diagnostic tool in dentistry, especially for patients who are medically compromised.

A Clinical Study of Basal Cell Carcinoma.

Introduction:Basal cell carcinoma (BCC) is a non-melanocytic skin malignancy arising from basal cells of epidermis or follicular structures. Etiology of BCC is a multifactorial combination of genotype, phenotype, and environmental factors. There are several clinical variants of BCC including nodular, cystic, superficial, morphoeic, keratotic, pigmented and micronodular.Aim:The aim of our study was to analyze the recent clinical trends of basal cell carcinoma by reviewing a single institution’s experience.Methods:Total number of 422 patients clinically diagnosed with basal cell carcinoma were included in the study. Data on age, gender, skin type, personal and family history, duration of disease, localization of lesions, clinical type of lesions, and recurrence rate were collected and analyzed. The data were statistically evaluated.Results:More than 80% of all BCC’s were located on sun-exposed skin areas (p<0.05).The male /female ratio was 1:0.92. The nodular BCC was the most frequent type (59.2%), followed by the superficial (16.1%), pigmented (15.2%) and morphoeic (9.5%) types. The nodular and pigmented types were predominant located on the head and neck, whereas the trunk was the most common location for the superficial type (p<0.05). The tumor is commonly found in concomitance with skin lesion related to chronic sun exposure, such as actinic keratoses, solar lentigines and facial telangiectasia. During this study period, 41 cases showed recurrence of the cancer as the overall recurrence rate was 9.7%. There were no cases with metastasis or fatal outcome.Conclusions:The factors related to the development of BCC were older age and exposure to ultraviolet rays both in recreational and in occupational form. The prevention of BCC is based on the knowledge of risk factors, early diagnosis and treatment, particularly in susceptible populations.

Merkel cell carcinoma: long-term follow-up of a single institution series and clinical outcomes by immunological status

Merkel cell carcinoma (MCC) usually arises in sun-exposed areas of older patients and might be more aggressive in the immunocompromised. We performed a retrospective chart review of 40 consecutive MCC patients treated at our institution between the years 2006-2017. Clinical and epidemiologic data were utilized and therapy and survival were analyzed. Compared to Surveillance, Epidemiology, and End Results (SEER) data, our population was entirely Caucasian (100% versus 95%; P=0.11) and male predominant (75% versus 63%; P=0.11). The median age was 76. The patients more often had Tumor-Node-Metastasis (TNM) stage I disease (50% versus 39%; P=0.00003) and a primary tumor size <2cm (57.5% versus 34%; P<0.01). They received more frequently lymph node dissection (70% versus 63%, P=0.002) compared with the SEER findings. We identified a subset of immunocompromised patients (n=10) who presented with more stage III disease (40% versus 33%; P=0.021). Time to death averaged 290.1 days in this subset versus 618.2 days (P<0.001) in immunocompetent patients and their likelihood of death was 5 times higher. As clinical outcomes in MCC patients vary by immunological status, a multidisciplinary tumor-board approach may better optimize individual patient management.

Recent updates in the management of Merkel Cell Carcinoma

Merkel cell carcinoma is an aggressive non-melanomatous cutaneous tumour of neuroendocrine origin with an increasing incidence in the recent years. It is a tumour of the elderly and immunosuppressed, which most often appears on sun-exposed areas of the body. The clinical features of the cutaneous or subcutaneous lesions hardly contribute to the diagnosis, and, hence, histopathology and immunohistochemistry play a vital role in diagnosis. The latest staging system by the American Joint Committee on Cancer includes non-nodal invasion to adjacent structures i.e. bone, muscle, fascia, or cartilage into the criteria, in additionto size and depth of invasion. The management reliesheavily on a multidisciplinary approach due to rarity of incidence of this disease. According to the international guidelines, surgical management is still the preferred choice. The beneficial role of adjuvant radiotherapy has now been more clearly documented. Data is insufficient to assess whether chemotherapy improves disease-free or overall survival.

Dermoscopy of Keratoacanthoma Centrifugum Marginatum.

Dermoscopy of Keratoacanthoma Centrifugum Marginatum.

Topical tranexamic acid with microneedling versus microneedling alone in treatment of melasma: clinical, histopathologic, and immunohistochemical study

Background Melasma is an acquired disorder of symmetrical hypermelanosis that involves sun-exposed areas of the skin. Although multiple therapeutic modalities have previously been tried, successful, truly effective treatment options for this condition have been few and quite elusive. Objectives To compare the therapeutic efficacy of topical tranexamic acid (TXA) with microneedling versus microneedling alone in the treatment of melasma and to evaluate the changes that occur clinically, histologically, and immunohistochemically. Patients and methods This study was conducted on 42 patients with melasma, randomly divided into two groups. In group I, each patient was subjected to a series of six sessions of skin microneedling and TXA application, whereas in group II, six sessions of microneedling alone were performed, with 2-week interval. Results Clinically, the mean melasma area and severity index (MASI) score was significantly decreased in both groups with statistically significant higher reduction scores in group I compared with group II. Histopathologically, epidermal hyperpigmentation and dermal melanophages were significantly reduced after treatment with more obvious reduction in group I. The number of melanoma antigen recognized by T cells-1-positive cells showed significant reduction in both groups; this reduction was statistically higher in group I than group II. Conclusions Although microneedling alone produced significant lightening effect, topical TXA combined with microneedling achieved more satisfactory results.

Pellagra: A forgotten ailment in current clinical practice

We rarely come across deficiency of niacin in the current clinical practice. Deficiency of niacin (Vitamin B3) leads to pellagra with constellation of symptoms affecting gut, skin, and nervous system. We present a case of nutritional deficiency of niacin presenting as pellagra in a 45-year-old female. The patient was treated successfully with Vitamin B3 supplementation. Pellagra shall be considered in differential diagnosis of chronic diarrhea when associated with skin lesions affecting sun-exposed areas.

Increasing incidence of lentigo maligna and lentigo maligna melanoma in Catalonia.

Recent epidemiological studies suggest that past data where superficial spreading melanoma was by far the most common subtype of melanoma may not reflect current patterns of sun exposure or other risk factors more involved in other subtypes of melanoma as lentigo maligna (LM) or lentigo maligna melanoma (LMM). In order to measure the current situation in our country, all cases of LM and LMM diagnosed in 23 hospitals in Catalonia, from 2000 to 2007, were recorded. Although for the global period LM/LMM represented only 8.4% of cases, an increasing trend in this percentage was observed throughout the study period (from 6.9% [27 cases] in 2000 to 13.1% [94 cases] in 2007). Also, an increasing incidence of LM/LMM was observed, especially in chronically sun-exposed areas (85.5% involving the head and neck region). During the 8years of the registry, the mean Breslow thickness of LMM remained stable. However, the increase in the number of LM (insitu) cases was significantly higher than the increase of the invasive ones. An important observation from this data is that aging of population and current sun exposure patterns could keep increasing the incidence of LM/LMM, which may become an important public healthcare problem, over the other histological subtypes. In order to establish primary or secondary preventive measures to the LM/LMM risk-population, it is imperative to highlight the importance of chronic sun damage as a melanoma risk factor, and not only sunburn, most commonly addressed in melanoma prevention campaigns.

Blisters on the sun-exposed area: as a clue for underlying hepatitis C virus infection

A 45-year-old woman presented with recurrent fluid-filled blisters over hands, feet, forearm and face for the last 5 years. Blisters ruptured with minor trauma or spontaneously after 6–7 days. Lesions...

Demographics, Risk Factors, and Incidence of Melanoma in Patients in the New England VA Healthcare system.

A recent study found that the incidence of melanoma and melanoma-related mortality was decreasing in residents of the New England region. However, it is unknown whether this trend is conserved in Veterans of New England who constitute more than 14% of the national Veteran population. Given this, our goal was to analyze the incidence of melanoma in patients of Veteran Integrated Service Network-1 (VISN-1) (geographically consisting of VA health care facilities in Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont) and to calculate an incidence rate ratio (IRR) of melanoma in VISN-1 compared to the general population. Additional goals were to ascertain the risk/susceptibility of this patient population with a view to improve quality of care and outcomes. Data for 523 cases of melanoma [2000-2011] were obtained from the regional branch of the Veterans Affairs Central Cancer Registry (VACCR) within the geographic area comprising VISN-1. A detailed retrospective chart review was conducted on these cases to gather demographic, risk factor, and clinical practice data. Demographic and incidence data from VISN-1 were compared to the general population via data from Surveillance, Epidemiology and End Results Program (SEER) from the same time period. Person-years (PY) were calculated for both populations to measure IRRs which was further standardized for age and gender. VISN-1 patients were predominantly older (94.26% >50 years), Caucasian (99.43%) males (96.75%). Compared to the general population, VISN-1 patients experienced more invasive lesions defined as stage T1 or greater (4.33% vs. 57.12%, p < 0.001), but reduced melanoma-associated mortality (40.96% vs. 19.05%, p < 0.001) although all-cause mortality was approximately doubled (52.20% vs. 26.14%, p < 0.001). Metastatic disease-rates were similar in both [approximately 4% in both]. IRR of melanoma in VISN-1 patients was 0.36 (95% CI: 0.20-0.67; p = 0.0063) which persisted in all age groups/genders. 60.92% of VISN-1 patients had recreational sun-exposure history and 72.41% of tobacco use. 95.02% of melanomas were located in continuously/intermittently sun-exposed areas, 93.28% were surgically-treated with a median treatment delay of 31 days [range 18-48]. Median lost to follow-up was 0 day [range 0-681 days]. Compared to the general population, melanoma incidence was lower in the VISN-1 cohort, possibly due to decreased UV index in the New England region, protective effects of past tobacco use, improved access to care through the VA and regional public health educational efforts. Yet melanomas were more often invasive in the VISN-1 cohort due to advanced age and male sex both of which are associated with more advanced disease at diagnosis. A strength of this study is the calculation of IRR using PY as this method enhances accuracy of incidence calculations. The data were limited by the fact that the population was from one geographic region and consisted mainly of elderly Caucasian males. Descriptive variable data such as sun-protective habits and risk factors from military service are limited by potential recall bias given the retrospective study design. Further study is necessary to replicate these results and to compare our data to Veteran populations from different geographic regions within the USA.

IATROGENIC SYSTEMIC ALLERGIC CONTACT DERMATITIS FROM CETIRIZINE AND LEVOCETIRIZINE

Introduction H1 antihistamines are frequently utilized in the management of dermatitis-associated pruritus; they may be overlooked and are rarely considered as an etiology for dermatitis. Case Description A 76-year-old woman with a history of allergic rhinitis and hypertension was referred for one year of pruritic, erythematous papules/plaques scattered throughout the body, worse over sun-exposed areas. Prior dermatologic evaluation and biopsy were suggestive of allergic contact dermatitis. Patch testing was positive for fragrance mix, ethylenediamine, and balsam of peru. The patient discontinued all products containing these substances without improvement. She continued to develop new lesions. There were no new medications except cetirizine and then levocetirizine, which she continued for the management of pruritus. She was treated with multiple courses of systemic and topical corticosteroids, and hydroxychloroquine, without resolution. The patient was advised to discontinue levocetirizine, avoid cetirizine, and initiate fexofenadine. At follow up at two weeks and one year later, she reported complete resolution of the rash after discontinuation of levocetirizine. Discussion Piperazine derivative antihistamines, such as hydroxyzine, cetirizine, and levocetirizine, share a similar structure with ethylenediamine, which is a common etiology of contact dermatitis. Hypersensitivity to H1 antihistamines is rare. Continued use of H1antihistamines, despite lack of improvement or worsening of symptoms, may be incorrectly interpreted as a failure of response to treatment. Development of generalized dermatitis induced by cetirizine or levocetirizine is rarely reported. This case illustrates the importance of re-evaluation in patients who fail to respond to treatment with consideration of piperazine derivative H1 antihistamines as a possible trigger. H1 antihistamines are frequently utilized in the management of dermatitis-associated pruritus; they may be overlooked and are rarely considered as an etiology for dermatitis. A 76-year-old woman with a history of allergic rhinitis and hypertension was referred for one year of pruritic, erythematous papules/plaques scattered throughout the body, worse over sun-exposed areas. Prior dermatologic evaluation and biopsy were suggestive of allergic contact dermatitis. Patch testing was positive for fragrance mix, ethylenediamine, and balsam of peru. The patient discontinued all products containing these substances without improvement. She continued to develop new lesions. There were no new medications except cetirizine and then levocetirizine, which she continued for the management of pruritus. She was treated with multiple courses of systemic and topical corticosteroids, and hydroxychloroquine, without resolution. The patient was advised to discontinue levocetirizine, avoid cetirizine, and initiate fexofenadine. At follow up at two weeks and one year later, she reported complete resolution of the rash after discontinuation of levocetirizine. Piperazine derivative antihistamines, such as hydroxyzine, cetirizine, and levocetirizine, share a similar structure with ethylenediamine, which is a common etiology of contact dermatitis. Hypersensitivity to H1 antihistamines is rare. Continued use of H1antihistamines, despite lack of improvement or worsening of symptoms, may be incorrectly interpreted as a failure of response to treatment. Development of generalized dermatitis induced by cetirizine or levocetirizine is rarely reported. This case illustrates the importance of re-evaluation in patients who fail to respond to treatment with consideration of piperazine derivative H1 antihistamines as a possible trigger.

A clinico-epidemiological study of melasma

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Melasma is an acquired increased pigmentation of the skin, characterized by gray-brown symmetrical patches, mostly in the sun-exposed areas of the skin.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; The proposed study is an epidemiological cross sectional study which was carried out in the department of dermatology in a teaching institute from October 2007 to September 2008 at Pramukh Swami Medical College, Karamsad, Gujarat. A total of 60 patients were enrolled for the study over a period of one year.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; The main age group affected was 30-39 years i.e. 48.33% patients. 50 patients were females.18 patients had a positive family history of melasma. 12 patients had a positive history of using OC Pills. Malar region was the commonest affected area found in 52 patients followed by Centro-facial in 31 and least involvement was seen in forehead region in 24 patients. 20 patients reported association of occurrence of the lesions with pregnancy, 09 patients reported sunlight to be the offending agent.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Females were affected more commonly during their late third decade of life. Although we did not find the exact cause of melasma, we noticed that sun-exposure, pregnancy, and taking of oral contraceptive pills could precipitate or exacerbate the melasma.&lt;/p&gt;

Granuloma multiforme: an uncommon differential for leprosy.

Granuloma multiforme (GM) is a chronic granulomatous skin condition which is clinically characterised by annular lesions mainly over sun-exposed areas and histologically by focal necrobiosis and histiocytic granulomas. Its significance lies in the fact that it can clinically resemble tuberculoid leprosy and hence it can be missed. Here, we report a case of GM from India in a 55-year-old female agriculturist, with multiple asymptomatic large annular rings of papules over the photo-distributed areas. Histopathology helps in confirming the diagnosis and in differentiating it from similar clinical and histologic mimics such as granuloma annulare, tuberculoid leprosy, interstitial granulomatous dermatitis or annular sarcoid. Though a high degree of suspicion is needed to diagnose GM, it should be considered as a differential for various annular conditions.

A Unique Case of Metastatic Merkel Cell Carcinoma Without a Dermatologic Primary

INTRODUCTION: Merkel cell carcinoma (MCC) is a rare neuroendocrine carcinoma. It is predominately seen on sun-exposed areas in elderly patients or in immunocompromised populations. About 80% of cases are associated with Merkel cell polyomavirus, suggesting a viral-induced oncogenesis. The most common presentation is a rapidly growing pink-red, dome-shaped nodule on the skin. We present a rare case of metastatic MCC diagnosed by endoscopic ultrasound of an incidentally discovered portacaval lymph node. CASE DESCRIPTION: An 81-year-old male with no dermatologic history presented to the emergency department with fever and chills. His fever was documented at 39.3 deg C, was tachycardic at a HR of 117, and a leukocyte count of 11.6. He also endorsed unintentional weight loss of nearly 20 lbs. The ED obtained abdomen/pelvis which noted radiographic evidence of diverticulitis as well as a large portacaval lymph node measuring 8.6 x 4.5 cm. He was discharged oral antibiotics for treatment of diverticulitis with plan for outpatient endoscopic evaluation of the enlarged lymph node. An upper endoscopy was performed and no intraluminal masses or lesions were noted. Next, linear endoscopic ultrasound was performed which identified the portacaval lymph node which measured 42.3 mm x 37.4 mm. We used a 25-gauge fine needle biopsy with on-site cytopathology confirming cellular adequacy. Cytology demonstrated positive CK20, CD56, and synaptophysin with high rate of KI-67 and negative TTF-1 consistent with neuroendocrine differentiation and a diagnosis of Merkel cell carcinoma. The patient was referred to oncology for further management. Staging workup with a PET/CT noted metastatic disease also involving the right shoulder and he was subsequently initiated on systemic immunotherapy with the checkpoint inhibitor pembrolizumab.1275_A.tif Figure 1: Coronal view of CT abdomen/pelvis which identified a bilobed porta-caval lymph node measuring 55.2 mm x 64.5 mm.1275_B.tif Figure 2: Endoscopic Ultrasound view of porta-caval lymph node measured at 48.5 mm sampled via FNA which diagnosed the finding of Merkel Cell Carcinoma.DISCUSSION: MCC is a rare, aggressive neuroendocrine carcinoma that usually presents with a skin lesion. Only 0.4% of cases have been reported in locations other than the skin. While there are multiple reports of recurrence of MCC in the gastrointestinal tract, very few cases present initially without an apparent skin lesion. Gastroenterologists should be aware of this uncommon neoplasm, given that MCC is an aggressive malignancy that requires prompt diagnosis and oncologic treatment in order to optimize patient outcomes.

Enhanced expression of nidogen 1 around the nest of basal cell carcinoma compared with that around squamous cell carcinoma.

Basal cell carcinoma (BCC) is a malignant skin tumor originating from cells of the epidermal basal layer and adnexal epithelium, especially in sun-exposed areas. Unlike squamous cell carcinoma (SCC), BCC has a propensity to grow only locally possibly due to differences in the surrounding microenvironment including the basement membrane (BM) and stroma. To investigate the components constituting the BM and surrounding connective tissue in BCC and SCC, we analyzed the expression of BM proteins, nidogen 1 (NID1) and type IV collagen (COL4). We compared the immunohistochemical expressions of NID1 and COL4 among tumor specimens from BCC, SCC and its precancerous condition, actinic keratosis (AK), (n = 5 each condition). The expressions of NID1 and COL4 were both decreased around the tumor nest of SCC. In contrast, the expressions of both NID1 and COL4 around the nest of BCC were much higher than in the peri-lesional normal skin not only at the BM, but also in the surrounding stromal tissue. Our findings imply that the surrounding stromal cells of BCC, but not SCC or AK, excessively produce NID1 and COL4, which may be involved in preventing BCC cells from destroying the BM and invading the dermis.

Primary Merkel cell carcinoma of the earlobe in a young healthy man.

Merkel cell carcinoma (MCC) is an uncommon neuroendocrine cutaneous tumor with poor prognosis. It has the high rate of recurrence, mortality, regional nodal involvement, and distant metastases. It is difficult to diagnose MCC because of its non-specific clinical findings. It usually occurs on sun-exposed areas of the skin, mostly at head and neck. There is a difference in the incidence and prognosis according to site in the head and neck. However, there is no consented site-specific diagnosis, treatment or follow-up protocol for MCC at the head and neck. We herein report a case of MCC arising in the right earlobe of an otherwise healthy young man who has been diagnosed early, thereby successfully treated. With our closed follow-up, there was no tumor recurrence or complication at 33 months after diagnosis.

Clinically amelanotic or hypomelanotic melanoma: Anatomic distribution, risk factors, and survival

The recognition and diagnosis of clinically amelanotic or hypomelanotic melanoma is a challenge. This study aimed to examine the anatomic distribution and risk factors associated with clinically amelanotic or hypomelanotic melanoma and compare the survival of patients with clinically amelanotic or hypomelanotic melanoma with that of patients with pigmented melanoma. A prospective cohort study of all cases of primary invasive melanoma managed at a tertiary referral center was performed. There were a total of 3913 invasive melanomas, and 384 (9.8%) were clinically amelanotic or hypomelanotic. Skin phototype I; red as well as blonde hair color; actinic keratoses; nodular, desmoplastic, and lentigo maligna subtype; increased Breslow thickness; and mitoses were independently associated with amelanotic or hypomelanotic melanoma (P<.05). After adjustment for subtype and thickness, the face, ears, lateral aspect of the neck, upper portion of the arm, posterior aspect of the forearm, dorsal aspect of the hand, and anterior aspect of the lower portion of the leg were associated with increased odds of amelanotic or hypomelanotic melanoma when compared with the upper portion of the back (P<.05). Mortality risk from melanoma appeared greater for amelanotic or hypomelanotic melanoma than for pigmented melanoma (hazard ratio, 1.5; 95% confidence interval, 1.1-2.1) but was similar once Breslow thickness was taken into account. Single tertiary referral center. Although clinically amelanotic or hypomelanotic melanoma can occur on all body sites, it is more common on chronically sun-exposed areas. Clinicians should have an increased index of suspicion in patients with a sun-sensitive skin phenotype, red hair, and associated actinic keratoses.