An unusual metastasis of lung adenocarcinoma: Biceps brachii muscle

Right Thigh Mass Metastasis from Lung Cancer Mimicking Primary Soft Tissue Sarcoma: A Case Report

BACKGROUND Soft tissue metastases (STMs) are less common than bone metastases and sometimes misdiagnosed as primary soft tissue malignancies. Skin, lungs, and breast are the most common primary lesions of STMs and rarely the presenting symptoms. We present an STM from lung adenocarcinoma that became a presenting symptom in nonsmoking woman. CASE REPORT A 47-year-old woman presented to our hospital with a painful mass in her right thigh and weight loss of 10 kg for 4 months. Femoral radiograph revealed a lesion suggestive of bone sarcoma. However, magnetic resonance imaging (MRI) showed it was more likely a primary soft tissue sarcoma. A small mediastinal mass was noticed on preoperative chest radiograph, and the patient denied any symptoms except the mass in the right thigh. Our clinicopathological conference team decided to perform a biopsy of mediastinal and right thigh masses. Histopathology examinations confirmed the right thigh mass as soft tissue metastasis from mediastinal mass, confirmed as lung adenocarcinoma. We treated the patient with palliative care with zoledronic acid and gefitinib. At the 6-month follow-up, the patient's symptoms significantly improved, and MRI showed a marked size reduction. CONCLUSIONS Diagnosis of STM can be difficult when presenting as the primary manifestation. Failure to identify promptly can lead to rapid disease progression and unfavorable prognosis. Failure to diagnose primary malignancy during biopsy occurs in approximately 28% of cases. This report has the potential to facilitate the avoidance of unnecessary procedures and highlight the importance of using a multidisciplinary approach in managing cases with malignancy.

An Unusual Case of Lung Adenocarcinoma Metastasis to the Tricep Muscle: Four Years Disease-Free After Surgical Resection and Radiotherapy

Lung cancer is one of the leading causes of cancer-related death worldwide. Lung cancer commonly metastasizes to the liver, bone, and brain, but metastasis to skeletal muscles is rare. The development of metastasis in skeletal muscles indicates stage IV disease with a poor prognosis. The most effective treatment strategy is unclear. Palliative radiotherapy is often used to treat skeletal muscle metastases, and patient survival is poor, with an average survival of one year. Here we discuss the case of a 76-year-old female diagnosed with lung adenocarcinoma with metastasis to the trapezius muscle. Initially, she was treated with stereotactic body radiotherapy for stage T1 lung adenocarcinoma. Her follow-up surveillance positron emission tomography (PET) scan in 11 months showed an abnormal focal area of increased activity localizing to the long head of the right triceps muscle. The diagnosis was confirmed with an ultrasound-guided biopsy of the trapezius muscle. Following that, the patient underwent wedge resection of the right middle and upper lobe of the lung and partial right trapezius resection. Afterward, she was given radiation therapy at the tricep resection site. She remained disease-free for four years after excision and radiation therapy.

Immunization against ROS1 by DNA Electroporation Impairs K-Ras-Driven Lung Adenocarcinomas ​

Non-small cell lung cancer (NSCLC) is still the leading cause of cancer death worldwide. Despite the introduction of tyrosine kinase inhibitors and immunotherapeutic approaches, there is still an urgent need for novel strategies to improve patient survival. ROS1, a tyrosine kinase receptor endowed with oncoantigen features, is activated by chromosomal rearrangement or overexpression in NSCLC and in several tumor histotypes. In this work, we have exploited transgenic mice harboring the activated K-Ras oncogene (K-Ras^G12D) that spontaneously develop metastatic NSCLC as a preclinical model to test the efficacy of ROS1 immune targeting. Indeed, qPCR and immunohistochemical analyses revealed ROS1 overexpression in the autochthonous primary tumors and extrathoracic metastases developed by K-Ras^G12D mice and in a derived transplantable cell line. As proof of concept, we have evaluated the effects of the intramuscular electroporation (electrovaccination) of plasmids coding for mouse- and human-ROS1 on the progression of these NSCLC models. A significant increase in survival was observed in ROS1-electrovaccinated mice challenged with the transplantable cell line. It is worth noting that tumors were completely rejected, and immune memory was achieved, albeit only in a few mice. Most importantly, ROS1 electrovaccination was also found to be effective in slowing the development of autochthonous NSCLC in K-Ras^G12D mice.

Pulmonary Adenocarcinoma Presenting as Paraspinal Muscle Metastatic Mass

A 39-year-old male presented with a painful paraspinal mass, which had been present for several weeks. The mass had previously been treated with oral sulfamethoxazole and trimethoprim DS, as the patient reported a history of “boils,” with no improvement in his pain or size of the mass. No further diagnostic workup was pursued until he was admitted with intractable pain. Eventual biopsy revealed adenocarcinoma, likely of pulmonary origin. This report, as well as other incoming cases, highlights this rare phenomenon of muscular metastases as the sole presentation of a distant primary malignancy.