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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 -
Veterinary Pathology Apr 2024Histologic diagnosis of less well-differentiated cases of canine extramedullary plasmacytomas (CEMPs) may require immunohistochemical confirmation to discriminate these...
Histologic diagnosis of less well-differentiated cases of canine extramedullary plasmacytomas (CEMPs) may require immunohistochemical confirmation to discriminate these tumors from other round cells tumors including lymphoma, cutaneous histiocytoma, and amelanotic melanomas. CEMPs are characterized by widespread immunoreactivity for multiple myeloma 1 (MUM1) antigen and λ light chains, while the melanocytic marker melan-A has been reported to yield negative results. Here, 33 randomly selected CEMPs, 20 melanocytomas, and 20 malignant melanomas were immunohistochemically tested for MUM1, melan-A, and PNL2. In addition, CEMPs were examined for PAX5, E-cadherin, CD3, CD18, CD20, S100, as well as λ and κ light chain immunoreactivity. All CEMPs were characterized by labeling for MUM1 and λ light chain, as well as variable immunopositivity for the remaining antibodies. Notably, 13 cases of CEMPs (39.4%) exhibited immunolabeling for melan-A. Melanocytic tumors immunolabeled for melan-A (40/40; 100%) and PNL2 (34/40; 85%). An unexpected cytoplasmic immunoreactivity for MUM1 was observed in 2 melanocytic tumors. Summarized, MUM1 or melan-A immunomarkers alone are not sufficient to differentiate between CEMPs and amelanotic melanomas and should be part of a larger immunopanel including λ light chain, CD20, and PNL2.
PubMed: 38642035
DOI: 10.1177/03009858241246979 -
Veterinary Pathology Apr 2024In felines, ocular and nonocular melanomas are uncommon tumors that represent a diagnostic challenge for pathologists, especially when amelanotic. To date, the...
In felines, ocular and nonocular melanomas are uncommon tumors that represent a diagnostic challenge for pathologists, especially when amelanotic. To date, the immunohistochemical diagnostic panel in cats is based on specific melanocytic markers (Melan-A and PNL2) and a nonspecific but sensitive marker (S100). In human medicine, SOX-10 is reported to be a sensitive antibody for the detection of melanoma micrometastasis in the lymph node. TRP-1, an enzyme involved in melanogenesis, has recently been used in humans and dogs as a specific melanocyte marker. The aim of this study was to evaluate the cross-reactivity and the expression of SOX-10 and TRP-1 antibodies in feline normal tissue and melanocytic tumors. Thirty-one cases of ocular, cutaneous, and oral melanomas were retrospectively evaluated and confirmed by histopathological examination and by immunolabeling with Melan-A and/or PNL2. SOX-10 nuclear expression in normal tissues was localized in epidermal, subepidermal, hair bulb, and iridal stromal melanocytes and dermal nerves. In melanomas, nuclear expression of SOX-10 was detected in ocular (11/12; 92%), oral (6/7; 86%), and cutaneous sites (12/12; 100%). TRP-1 cytoplasmic immunolabeling in normal tissue was observed in epidermal and bulbar melanocytes and in the lining pigmented epithelium of the iris and in its stroma. Its expression was positively correlated to the degree of pigmentation in the tumor and was observed in 75% of ocular (9/12), 43% of oral (3/7), and 33% of cutaneous melanomas (4/12). This study demonstrated the cross-reactivity of SOX-10 and TRP-1 antibodies in feline non-neoplastic melanocytes and their expression in ocular and nonocular melanomas.
PubMed: 38613415
DOI: 10.1177/03009858241244850 -
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 -
Journal of the European Academy of... Apr 2024Differential diagnosis of amelanotic/hypomelanotic melanoma among solitary flat pink lesions is challenging, due to limited clinical and dermoscopic clues. Dermoscopy...
BACKGROUND
Differential diagnosis of amelanotic/hypomelanotic melanoma among solitary flat pink lesions is challenging, due to limited clinical and dermoscopic clues. Dermoscopy and reflectance confocal microscopy assessments improve diagnostic accuracy, but their combined capacity among solitary flat pink lesions is yet to be defined.
OBJECTIVES
To determine (i) whether diagnostic accuracy is improved with combined dermoscopy and reflectance confocal microscopy, (ii) a model to estimate probability of flat amelanotic/hypomelanotic melanoma among solitary flat pink lesions.
METHODS
A retrospective single-centre study of solitary flat pink lesions, excised for suspected malignancy between 2011 and 2022 was performed. Images were independently evaluated by two dermatologists, blinded to histopathological diagnosis. Diagnostic performance was evaluated on the receiver operating characteristic curve and the area under the curve. Predictive features were identified by univariate and multivariate logistic regression analyses. A final predictive nomogram of independent risk factors was calculated by backward likelihood ratio. Hypothesis being tested was formulated before data collection.
RESULTS
A total of 184 patients (87 females, 47.3%) were included; mean age was 57.6 years (19-95). Combined dermoscopy and reflectance confocal microscopy was more sensitive (83%, CI 69.2-92.4 and 91.5%, CI 79.6-97.6) than dermoscopy alone (76.6%, CI 62.0-87.7 and 85.1%, CI 71.7-93.8). Predictive features defined the new model, including linear irregular vessels (4.26-folds, CI 1.5-12.1), peripheral pigment network (6.07-folds, CI 1.83-20.15), remnants of pigmentation (4.3-folds, CI 1.27-14.55) at dermoscopy and atypical honeycomb (9.98-folds, CI 1.91-51.96), disarranged epidermal pattern (15.22-folds, CI 2.18-106.23), dendritic pagetoid cells in the epidermis (3.77-folds, CI 1.25-11.26), hypopigmented pagetoid cells (27.05-folds, CI 1.57-465.5), and dense and sparse nests (3.68-folds, CI 1.24-10.96) in reflectance confocal microscopy. Diagnostic accuracy of the model was high (AUC 0.91).
CONCLUSIONS
Adjunctive reflectance confocal microscopy increases diagnostic sensitivity of flat amelanotic/hypomelanotic melanoma differential diagnosis. The proposed model requires validation.
PubMed: 38572809
DOI: 10.1111/jdv.19991