Mesenchymal-epithelial transition factor exon 14 skipping mutation-positive granulocyte colony-stimulating factor-producing lung adenocarcinoma mimicking lung abscess: A case report.

Granulocyte colony-stimulating factor (G-CSF)-producing lung tumours are rare, with their imaging features and effective treatments remaining elusive. Similarly, mesenchymal-epithelial transition (MET) exon 14 skipping mutations are also uncommon. Herein, we report a case of G-CSF-producing lung adenocarcinoma positive for a MET exon 14 skipping mutation, mimicking lung abscess. A 61-year-old man presented with cough and high fever. Contrast-enhanced chest computed tomography revealed a mass with a cavity and internal fluid accumulation. The patient initially underwent diagnostic treatment for a lung abscess but was ultimately diagnosed with lung adenocarcinoma positive for a MET exon 14 skipping mutation. Following tepotinib therapy, the primary lesion shrank, and serum G-CSF levels decreased, leading to a diagnosis of G-CSF-producing lung cancer. G-CSF-producing lung tumours can present imaging findings that mimic lung abscesses. Tepotinib therapy may be effective for patients with MET exon 14 skipping mutation, including those with G-CSF-producing lung cancer.

Unusual Manifestation of Dermatomyositis: Exacerbation of Hypertriglyceridemia.

Systemic lupus erythematosus is known to cause autoimmune hyperlipidemia. We present a case in which hypertriglyceridemia was exacerbated by dermatomyositis. A 53-year-old woman with a medical history of undertreated hypertriglyceridemia complained of dyspnea and arthralgia. Despite the treatment, her triglyceride levels increased concurrently with the onset of arthralgia. She had characteristic skin manifestations and tested positive for anti-Jo-1 autoantibodies, leading to a diagnosis of dermatomyositis. Chronic inflammation may result in elevated triglyceride levels. When dermatomyositis is diagnosed, evaluating lipid abnormalities is important.