A rare case of endobronchial melanoma of unknown primary

Endobronchial melanoma metastasis. A rare relapse

Melanomas are skin derived malignant tumors exhibiting extreme diversity during disease progression in terms of time and site of metastasis. This is a rare case of a 68 year old, former smoker male, with a history of a cutaneous head melanoma which was treated 20 years ago. He presented with dyspnea and mild hemoptysis. On examination a solid mass found at the right lower lobe. Bronchoscopy performed and biopsies taken revealing endobronchial metastatic melanoma. Tissue genomics revealed two rare mutations. Finally patient received a doublet of immunotherapy and targeted therapy regiments. To the best of our knowledge this is a rare case of endobronchial metastasis 20 years after the treatment of the primary site. After so many years elapsed it is difficult to make a differential diagnosis between metastasis and a second primary endobronchial melanoma. Surgery and bronchoscopic modalities are promising only if they can be combined with immunotherapy and targeted therapies which are the game changers regarding the treatment of the disease.

Comprehensive Literature Review on Melanoma of Unknown Primary Site Triggered by an Intriguing Case Report

Melanoma is one of the most aggressive forms of skin cancer. While most melanomas have a discernible primary site, a small subset, approximately 3.2%, present as a metastatic disease without an identifiable primary origin, a condition known as melanoma of unknown primary (MUP). Unusual cases of primary melanoma have also been previously reported in the respiratory, gastrointestinal, and urogenital tracts. MUP typically is found in lymph nodes, subcutaneous sites, and visceral organs, with hypotheses about its origin including spontaneous primary tumor regression and ectopic melanocytes. MUP presents unique challenges in diagnosis and treatment due to the absence of a detectable primary tumor. Understanding its genetic and molecular features, epidemiology, prognostic factors, and treatment options is crucial for optimizing patient care and outcomes in this subset of melanoma patients. We conducted an extensive literature review triggered by a case report of a patient with suspected MUP. A 51-year-old woman was transferred from another hospital where an incision was performed for a suspected superinfected hematoma of the left thigh. Since the patient showed high leukocytosis and redness and swelling of the thigh, local debridement, drainage, and excisional biopsy of the tumor mass were performed in our unit in the emergency setting, and the tumor was taken for histopathology evaluation. Intraoperatively, the mass appeared nonspecific. The permanent histopathology report established a diagnosis of melanoma, with tumor proliferation also involving lymphoid tissue, and despite broad clinical and imagistic assessments, the primary melanoma could not be identified. Clinicians must be aware of the varied clinical manifestations of malignant melanoma, especially in cases of occult melanoma where the primary site is not evident.

Melanoma of Unknown Primary With Metastasis to the Brain: A Case Report and Review of the Literature

We present the case of a 72-year-old male found to have melanoma of unknown primary (MUP) in the lung with brain metastasis. The patient has a history of prostate cancer with radical proctectomy in 1999, hypertension with right-sided heart failure, and bilateral cataracts treated operatively. He presented to their home hospital after an unwitnessed fall, with a history of left-sided weakness. He was found to have a parietal lobe mass and two lung masses, where he was transferred to our hospital for a higher level of care. Biopsy of the lung lesion revealed melanoma, and the patient did not have any skin or mucosal foci present to indicate a primary source. We present this case in conjunction with a review of the literature. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, our review resulted in 31 MUP case reports. Data was extracted on epidemiology, clinical presentations, diagnostics, treatment, and outcomes. The mean age was 57.5 with a male-to-female ratio of 1:1.3. The greatest instances of MUP occurred in prior smokers and patients with comorbidities, accounting for 17.95% of cases each. Thirty-one percent of patients presented with a growing palpable mass, 21% with gastrointestinal symptoms, and 21% with B-symptoms. Biopsy was the diagnostic standard, and the majority of patients also underwent biomarker studies. Treatment varied widely, and many patients underwent multiple phases. Outcomes ranged from death within several months to a disease-free period of three years. Our paper highlights the complexity and nuances of diagnosing MUP and primary malignant melanoma of the lung (PMML) and calls for further investigations to improve diagnostic and therapeutic approaches for rare presentations of melanoma. Despite limitations in sample size and data heterogeneity, this study highlights the diverse presentation and disease course of MUP, necessitating further studies to optimize patient outcomes.

Primary endobronchial melanoma: a case report and clinical management indications

BACKGROUND

While cutaneous melanomas are well-documented, primary melanoma of the lung (PMML), particularly with endobronchial origin, remains rare and poorly characterized. This case report addresses gaps in understanding by presenting a comprehensive case of a 71-year-old male with primary endobronchial melanoma and conducting a systematic review of PMML cases.

CASE PRESENTATION

The patient, a former smoker, presented with dyspnea, cough, and hemoptysis. Imaging revealed left lung atelectasis and a suspicious nodule. Bronchoscopy identified an endobronchial mass, subsequently treated with argon plasma coagulation and resection. Biopsy confirmed melanoma. Extensive examinations ruled out a primary skin lesion. Despite initial treatment, recurrence led to pneumonectomy. Histopathology confirmed melanoma. The patient received treatment with pembrolizumab and ipilimumab, but with poor clinical benefit.

CONCLUSIONS

Primary endobronchial melanoma is a rare entity, comprising 0.01% of lung tumors. This case underscores diagnostic challenges and emphasizes histological criteria to distinguish primary from metastatic lesions. The pathogenesis remains unclear, with theories proposing foetal melanocyte migration or squamous metaplasia. Prognosis varies, necessitating radical surgical extirpation. A systematic review revealed diverse outcomes, supporting the need for further research. In conclusion, endobronchial melanoma involves an endoscopic and surgical management, but evolving therapies, such as immunotherapy, may reshape treatment paradigms. This case contributes to our understanding of PMML, guiding future research and clinical management. As therapeutic options evolve, continued research is crucial to refine our understanding and improve outcomes for this rare malignancy.