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Journal of Personalized Medicine May 2024Acral amelanotic melanomas (AAMs), a rare subset of melanomas located on acral sites such as the palms, soles, and subungual areas, are diagnostically challenging due to... (Review)
Review
BACKGROUND
Acral amelanotic melanomas (AAMs), a rare subset of melanomas located on acral sites such as the palms, soles, and subungual areas, are diagnostically challenging due to their lack of typical pigmentation and often benign clinical appearance. Misdiagnosis is common, leading to delays in treatment and potentially worse outcomes. This systematic review aims to synthesise evidence on cases of AAM initially misdiagnosed as other conditions, to better understand their clinical and epidemiological characteristics, diagnostic pitfalls, and management strategies.
METHODS
A comprehensive search of the MEDLINE/PubMed, EMBASE, and SCOPUS databases was conducted up to March 2024. Case reports and small case series of AAMs initially misdiagnosed as other conditions were included. Data on patient demographics, clinical presentation, and diagnostic methods were collected and analyzed.
RESULTS
Of the 152 records identified, 26 cases from 23 articles met the inclusion criteria. A demographic analysis revealed that the gender distribution appears to be perfectly balanced, with an age range of 38 to 91 years. Misdiagnoses included non-healing ulcers or traumatic lesions (37.5%), benign proliferative lesions (29.2%) and infectious lesions (20.8%). The foot was the most affected site (53.8%). Notably, a histological evaluation was performed in 50% of cases involving the upper extremities, in contrast to only 7.1% of cases involving the foot and 0% of cases of the heel. This discrepancy suggests a reluctance to perform biopsies in the lower extremities, which may contribute to a higher misdiagnosis rate in these areas.
CONCLUSIONS
The underutilization of biopsy in the diagnosis of lower extremity lesions contributes significantly to the misdiagnosis and delay in treatment of AAMs. Especially when the clinical assessment and dermoscopy are inconclusive, biopsies of suspicious lesions are essential. Immunohistochemistry and markers such as PRAME are critical in differentiating melanoma from other malignancies such as clear cell sarcoma. This review highlights the need for increased vigilance and a proactive diagnostic approach to increase early detection rates and improve prognostic outcomes.
PubMed: 38793100
DOI: 10.3390/jpm14050518 -
Life (Basel, Switzerland) Apr 2024Desmoplastic melanoma accounts for 5% of all cases of melanoma, but its diagnosis can be difficult due to its frequent clinical presentation with amelanotic lesions....
Desmoplastic melanoma accounts for 5% of all cases of melanoma, but its diagnosis can be difficult due to its frequent clinical presentation with amelanotic lesions. Histologically, spindled melanocytes surrounded by a collagenous stroma are observed. Compared with other types of melanoma, the desmoplastic types presents greater local aggression, and is more prone to local recurrence, but has a lower risk of lymph node metastasis. Early detection, accurate staging, and proper surgical management are the main factors associated with higher survival rates in melanoma patients. Reflectance confocal microscopy (RCM) has proven to be a valuable imaging tool in the diagnosis of skin neoplasms, being useful for orientating practitioners towards the diagnosis of melanoma and indicating the necessity of performing a diagnostic biopsy. We present the case of 52-year-old woman, who presented to the dermatology department with an irregular, dark-colored plaque in the right deltoid region. Dermoscopy showed asymmetry with an atypical network and some areas of regression. RCM revealed pagetoid cells in the upper epidermis, cell atypia, non-edged papillae, dermal inflammation, and nucleated cells in the dermis, which are highly suggestive of melanoma. A biopsy was also performed. A histopathology exam confirmed the diagnosis of superficially spreading melanoma with a desmoplastic component, and revealed a Breslow index of 0.9 mm, Clark level IV, an absence of mitoses, angiolymphatic invasion and regression, and complete excision. The CT and PET-CT scans were negative. A biopsy of the axillary sentinel lymph node was conducted, with a negative result obtained, establishing the IB stage of the disease. The patient will remain under follow-up to look for a recurrence or a new primary melanoma.
PubMed: 38792595
DOI: 10.3390/life14050574 -
Veterinary Sciences May 2024Twelve dogs with oral malignant melanomas (MM) were evaluated in this study, with demographic details indicating a balanced distribution of gender, age, and weight among...
Twelve dogs with oral malignant melanomas (MM) were evaluated in this study, with demographic details indicating a balanced distribution of gender, age, and weight among various breeds. Tumor locations varied, with diverse surgical procedures being performed, including mandibulectomies and maxillectomies. Lymphadenectomies were conducted, revealing a 16.66% metastatic rate in regional lymph nodes. At the time of surgery, clinical staging identified stages I, II, and III, with most cases having non-infiltrated margins and a high mitotic index. Follow-up revealed local recurrences and metastases, prompting additional surgeries and affecting survival rates. This study reports varying outcomes, with some dogs completing one year without recurrence, while others experienced progressive disease, leading to six oral melanoma-related deaths. The characteristics of melanotic melanoma and amelanotic melanoma are observed in order to study differences between them, the degree of aggressiveness, the mortality rate and the possibility of future therapeutic targets. Although high pigmentation has been correlated with a better outcome, we could not find any significant correlation between survival and achromia. Oral benign melanomas might exist, and this could justify variabilities between stage and survival; however, carefulness is required due to their unpredictable behavior. The findings underscore the complexity of oral melanoma cases and highlight the need for further research on effective management strategies.
PubMed: 38787198
DOI: 10.3390/vetsci11050226 -
Cureus Apr 2024Oral malignant melanoma (OMM) is extremely rare and usually has a poor prognosis. Early diagnosis is very important and can improve survival but it is usually difficult...
Oral malignant melanoma (OMM) is extremely rare and usually has a poor prognosis. Early diagnosis is very important and can improve survival but it is usually difficult due to a lack of symptomatology. We present the first case of a 39-year-old East European woman with oral amelanotic melanoma, who underwent surgery and adjuvant immunotherapy; however, after six months, she developed local recurrence. The patient continued immunotherapy with external radiotherapy targeting the oral tumor recurrence. During therapy, imagistic reevaluation brought evidence of bones, lungs, liver, endotracheal, and brain metastases. Histological differential diagnosis between amelanotic OMM and leiomyosarcoma was necessary to establish the right course of treatment. A series of complications further delayed chemotherapy administration, making the treatment in this case very challenging. The patient had a significant, although late response to immunotherapy, and maintained a good performance status during disease progression with a survival of 15 months until present.
PubMed: 38725781
DOI: 10.7759/cureus.57875 -
Oxford Medical Case Reports Apr 2024Amelanotic melanoma (AM) is a subtype of melanoma where the lesion demonstrates no pigmentation. This can lead to delays in referral with studies showing a higher...
Amelanotic melanoma (AM) is a subtype of melanoma where the lesion demonstrates no pigmentation. This can lead to delays in referral with studies showing a higher mortality rate. To determine the characteristics of AM lesions, we conducted a retrospective analysis of patients with confirmed AM. Of the 16 patients, 68.75% were male and the mean age at diagnosis was 78 years. The most common location for AM was the head (37.5%) which also demonstrated a higher mitotic rate (10.67 mm) compared to the average (7.31 mm). More than half of the lesions (56%) had been present for more than 1 year. With a misdiagnosis rate of 87.5%, the likelihood of delays were evident. There was no unifying feature on clinical assessment, however conspicuous vessel findings were noted on 62.5% of lesions. We have demonstrated that AM continues to remain a missed diagnosis with the potential for a more lethal cancer to form.
PubMed: 38680773
DOI: 10.1093/omcr/omae029 -
Oxford Medical Case Reports Apr 2024Immunosuppressed individuals face a significantly elevated risk of developing aggressive cutaneous malignancies, often surpassing the aggressiveness observed in...
Immunosuppressed individuals face a significantly elevated risk of developing aggressive cutaneous malignancies, often surpassing the aggressiveness observed in immunocompetent counterparts. Our patient exhibited several risk factors associated with melanoma development in renal recipients, including skin type, sun exposure, and the duration of immunosuppression. The determination of staging holds paramount importance as it directly influences both prognosis and subsequent management. It is crucial to handle suspected lesions with caution in these patients to facilitate early melanoma detection and enhance overall prognosis.
PubMed: 38680765
DOI: 10.1093/omcr/omae035 -
International Journal of Molecular... Apr 2024Animal tumors serve as reasonable models for human cancers. Both human and animal tumors often reveal triplet EPR signals of nitrosylhemoglobin (HbNO) as an effect of...
Animal tumors serve as reasonable models for human cancers. Both human and animal tumors often reveal triplet EPR signals of nitrosylhemoglobin (HbNO) as an effect of nitric oxide formation in tumor tissue, where NO is complexed by Hb. In search of factors determining the appearance of nitrosylhemoglobin (HbNO) in solid tumors, we compared the intensities of electron paramagnetic resonance (EPR) signals of various iron-nitrosyl complexes detectable in tumor tissues, in the presence and absence of excess exogenous iron(II) and diethyldithiocarbamate (DETC). Three types of murine tumors, namely, L5178Y lymphoma, amelanotic Cloudman S91 melanoma, and Ehrlich carcinoma (EC) growing in DBA/2 or Swiss mice, were used. The results were analyzed in the context of vascularization determined histochemically using antibodies to CD31. Strong HbNO EPR signals were found in melanoma, i.e., in the tumor with a vast amount of a hemorrhagic necrosis core. Strong Fe(DETC)NO signals could be induced in poorly vascularized EC. In L5178Y, there was a correlation between both types of signals, and in addition, Fe(RS)(NO) signals of non-heme iron-nitrosyl complexes could be detected. We postulate that HbNO EPR signals appear during active destruction of well-vascularized tumor tissue due to hemorrhagic necrosis. The presence of iron-nitrosyl complexes in tumor tissue is biologically meaningful and defines the evolution of complicated tumor-host interactions.
Topics: Animals; Nitric Oxide; Ditiocarb; Mice; Hemoglobins; Electron Spin Resonance Spectroscopy; Spin Trapping; Neovascularization, Pathologic; Cell Line, Tumor; Disease Models, Animal; Mice, Inbred DBA; Ferrous Compounds
PubMed: 38673758
DOI: 10.3390/ijms25084172 -
Anais Brasileiros de Dermatologia 2024
Topics: Humans; Melanoma, Amelanotic; Diagnosis, Differential; Skin Neoplasms; Leprosy; Male; Biopsy; Middle Aged
PubMed: 38658240
DOI: 10.1016/j.abd.2022.12.012 -
JAAD Case Reports May 2024
PubMed: 38650592
DOI: 10.1016/j.jdcr.2024.02.030 -
Annals of Medicine and Surgery (2012) Apr 2024Melanoma represents only 1% of all skin cancers. Acral lentigious melanoma (ALM) which usually arises from feet, is the rarest main subtype of melanoma. Subungual...
INTRODUCTION AND IMPORTANCE
Melanoma represents only 1% of all skin cancers. Acral lentigious melanoma (ALM) which usually arises from feet, is the rarest main subtype of melanoma. Subungual melanoma (SUM) is a rare variant of ALM. Amelanotic melanoma (AM) is found only in 4-27.5% of melanomas, and the mean age for patients affected by AM exceeds 50 years. Late diagnosing leads to unfavourable prognosis.
CASE PRESENTATION
The authors present a case of subungual amelanotic melanoma that affected the nail unit of the right thumb which is a rare case, especially when the patient is only 39 years old. The lesion enlarged over a year and was misdiagnosed many times and treated with no response. Sentinel node biopsy was positive and the patient was moved to a specialized hospital for treatment.
CLINICAL DISCUSSION
Diagnosing subungual amelanotic melanoma is challenging, not only because it is the rarest, but also it mimics many benign and malignant neoplasms due to the lack of pigmentation, in addition to the absence of clinical diagnostic features. AM exhibits a high growth rate helping in limiting the window for early detection.
CONCLUSIONS
Lately diagnosed subungual amelanotic melanoma usually associates with an increased risk of metastases, So it should be considered as a cause of any non-healing lesion. Early diagnosing gives patients the best chance for survival.
PubMed: 38576910
DOI: 10.1097/MS9.0000000000001860