Pulmonary melanoma and "crazy paving" patterns in chest images: a case report and literature review

A rare radiological presentation of pulmonary metastases from malignant melanoma

Malignant melanoma is a highly aggressive cancer with metastatic potential to various locations such as the lymph nodes, lungs, liver, brain, and bone. After the lymph nodes, the lungs are the most common site of malignant melanoma metastases. Pulmonary metastases from malignant melanoma commonly presents as solitary or multiple solid nodules, sub-solid nodules or miliary opacities on CT chest. We present a case of pulmonary metastases from malignant melanoma in a 74-year-old man which presented unusually on CT chest as a combination of patterns like "crazy paving," upper lobe predominance with subpleural sparing, and centrilobular micronodules. Video-assisted thoracoscopic surgery, wedge resection and tissue analysis were performed, which confirmed the diagnosis of malignant melanoma metastases, and the patient further underwent PET-CT for staging and surveillance. Patients with pulmonary metastases from malignant melanoma can have atypical imaging findings, therefore radiologists should be aware of these unconventional presentations to avoid any misdiagnoses.

Primary Pulmonary Malignant Melanoma Presenting as Bilateral Multiple Subsolid Nodules: A Case Report

Primary pulmonary malignant melanoma is an extremely rare type of melanoma. The radiologic features of primary pulmonary malignant melanoma are nonspecific; however, it almost always presents as a well-demarcated round or lobulated solitary solid nodule or mass. Herein, we report the case of a 78-year-old male with primary pulmonary malignant melanoma that was mistaken for primary pulmonary adenocarcinoma with lepidic growth and was seen as bilateral multiple subsolid nodules on CT.

Lung-only melanoma: UV mutational signature supports origin from occult cutaneous primaries and argues against the concept of primary pulmonary melanoma

Primary pulmonary melanoma (PPM) is an entity recognized by the thoracic WHO classification. However, given the absence of native melanocytes in the lung and the known phenomenon of regression of cutaneous melanomas, the existence of PPM has remained controversial. Herein we investigate clinicopathologic and genomic features of lung-only melanomas with the goal to clarify their site of origin. We identified 10 melanomas involving exclusively lung with no current or previous cutaneous, uveal, or mucosal primaries. Four patients had solitary lesions with mean size of 5.1 cm (range 3.0-10.1 cm), meeting the criteria of PPM. Four patients had 2-3 lesions and 2 patients had >10 lesions. All cases underwent targeted next-generation sequencing interrogating up to 468 cancer genes, which revealed mean tumor mutation burden of 42.6 per megabase (range 1.8 to 126) and frequent mutations involving BRAF, NRAS, NF1, KIT, and KRAS - a genomic profile typical of UV-associated cutaneous melanoma. Mutational signature was assessable for eight cases harboring >20 mutations. This revealed that all evaluable cases harbored a dominant UV signature. In addition, one nonevaluable case harbored a GG > AA TERT promoter variant that is highly specific for UV-mutagenesis. As control groups, using the same methodology, a dominant UV signature was identified in 97% (470/486) of cutaneous melanomas, whereas no lung adenocarcinoma (n = 291) exhibited this signature. Notably, the clinical and pathologic features of solitary melanomas, especially those with large size and epithelioid morphology, closely mimicked primary lung carcinomas, highlighting a major potential for misdiagnosis. In conclusion, presence of a UV signature provides direct evidence that nearly all lung-only melanomas in this series, including solitary lesions meeting the strict criteria of PPM, represent metastases from occult cutaneous melanomas. This suggests that lung-only melanomas should be considered as likely metastatic even in the absence of a known primary melanoma elsewhere.

Primary Melanoma of the Lung: A Systematic Review

Background and Objectives: The respiratory apparatus, generally affected by highly aggressive tumors like lung cancer and mesothelioma, is rarely affected by primary malignant melanoma. The aim of this review was to identify cases of primary malignant melanoma of the lung (PMML) published in the modern scientific literature, and to describe their main clinical, pathological and therapeutic features. Materials and Methods: A systematic search of publications in the electronic database PubMed has been performed using keywords, and the references of the selected articles were checked to identify additional missing studies. Results: Globally 52 papers reporting on 76 cases were identified. Among them there were 47 reports of a single case, three papers reporting on two cases each, and two larger case series published in 1997 and 2005 including eight and 15 cases, respectively. Conclusions: PMML was generally diagnosed in middle-aged males, without any apparent correlation with cigarette smoking. It was more frequently found in the lower lobes and the left lung. The tumors were generally pigmented, composed by epithelial and/or spindle cells with large nuclei and prominent nucleoli, nuclear atypia, and numerous mitotic figures; they commonly showed immunostaining for S-100, HMB 45 and Melan-A. Early detection and surgical resection were the main determinants of survival from this rare malignancy.

Pulmonary alveolar microlithiasis: no longer in the stone age

Pulmonary alveolar microlithiasis (PAM) is a rare parenchymal lung disease caused by variants in the SCL34A2 gene and characterised by the accumulation of intra-alveolar microliths. PAM has been reported in fewer than 1100 cases throughout the world. It is an autosomal recessive hereditary disease and often associated with consanguinity. Progress with respect to the genetic background and pathophysiology has resulted in an increased understanding of the disease in recent years. Until now, 30 genetic different SLC34A2 variants have been reported, which all are considered significant for disease development. There is no sex difference and the majority of cases are diagnosed at the age of 30–40 years. Many patients are asymptomatic and the diagnosis is made at random. When symptomatic, dyspnoea, cough, chest pain and fatigue are common complaints. The diagnosis of PAM can confidently be based on typical radiographic findings and genetic testing proving rare biallelic SCL34A2 gene variants. Bronchoalveolar lavage and histopathology may show microliths. There is no disease-specific treatment and management is supportive. Lung transplantation should be considered in advanced cases.

Pulmonary alveolar microlithiasis is a rare, autosomal recessive lung disease. Formation of alveolar microliths is caused by SCL34A2 variants. The prognosis is severe; respiratory failure is common. Lung transplantation is the only effective therapy.https://bit.ly/3dpkbRw

Concurrence of primary pulmonary malignant melanoma with invasive pulmonary adenocarcinoma: a case report

Background

Primary pulmonary malignant melanoma (PPMM) is an extreme rarity in clinic practice, accounting for only 0.01% of all primary pulmonary tumors. And its diagnosis should meet clinical and pathological diagnosis criteria in addition to excluding the possibility of metastatic melanoma. The mainstay of treatment is surgery. The concurrence of primary pulmonary malignant melanoma and invasive pulmonary adenocarcinoma has not been reported before.

Case presentation

Herein we report the case of a 39-year-old woman who was asymptomatic and accidently found to have the concurrence of PPMM with invasive pulmonary adenocarcinoma. Before considering the diagnosis of primary pulmonary malignant melanoma, a systemic positron emission tomography-computed tomography (PET-CT) was done to excluding primary tumor metastasis from other sites. The pathological biopsy proved that two lesions in the right middle lobe were invasive pulmonary adenocarcinomas and the mass in the right lower lobe was malignant melanoma. She underwent right middle and lower lobectomy of the lung with mediastinal and hilar lymph dissection. She refused adjuvant chemotherapy, genetic molecular testing or immunotherapy. Fifteen months later she had brain metastasis. Then she received brain radiotherapy and underwent follow-up at the outpatient clinic regularly.

Conclusions

We experienced a case of concurrent PPMM and invasive pulmonary adenocarcinoma. The patient reported here is the first case of primary pulmonary malignant melanoma combined with invasive pulmonary adenocarcinoma. This patient remained disease-free 15 months after lung surgery.

Primary Pulmonary Malignant Melanoma Found While Evaluating New Onset Cough: A Case Presentation and Literature Review

Malignant melanoma is a nonepithelial neoplasm of melanocytes. It is tremendously rare for this condition to primarily involve the respiratory tract, accounting only for 0.01% of the lung malignancies. It often presents as a solitary nodule provoking mass effect and/or obstructive symptom. It most commonly affects patients 50 years old and older, with no gender predilection. Complete surgical excision is the treatment of choice; nevertheless, chemotherapy or radiation might be necessary depending on tumor location and/or metastasis status. Recently, biochemotherapy and immunotherapy have emerged as promising treatment modalities. We present a case of Primary Pulmonary Malignant Melanoma (PPMM) in a 76-year-old male with no previous personal or family history of cancer who presented with new onset nonproductive cough. We also present an analysis with high yield points summarizing clinical features, diagnostic workup, and management of PPMM. Finally, we post a table summarizing all the cases ever reported in English literature.

Primary Pulmonary Malignant Melanoma: Report of an Important Entity and Literature Review

Malignant melanoma involving the respiratory tract is nearly always metastatic in origin, and primary tumors are extremely rare. Published data on primary pulmonary malignant melanomas are limited. Up to now 40 relevant cases have been reported in the English literature. Herein, we report a case of a 56-year-old female patient who presented with intracranial metastases due to primary pulmonary melanoma. She underwent bronchoscopy and died 5 months after the initial diagnosis despite the administered biochemotherapy and subsequent immunotherapy. To establish the diagnosis of primary pulmonary malignant melanoma, any extrapulmonary origin was excluded by detailed examination and radiographic imaging. Moreover, an extensive review of the literature regarding this rare entity has been performed.