Long-term complete response in a breast cancer patient with skeletal muscle metastases diagnosed using 18F-FDG-PET

Detection of muscle metastases on 18F-fluorodeoxyglucose positron emission tomography/computed tomography scan in 13 cases

Muscular metastases (MMs) form an infrequent entity, and their physiopathology is still not well-defined. In this study, we estimated the incidence of MMs that were detected by ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography and also specified their metabolic characteristics. This study includes 13 patients with MMs from a remotely located primary tumor. The results of this study showed an incidence of MMs at about 1%, with the most frequently involved muscles being iliopsoas and paraspinal. Lung cancer seems to be the most common tumor that causes MMs. Furthermore, these MMs vary in size and physiological uptake; they seem to be out of the ordinary and easily detected. They are often associated with other extra muscular locations and frequently involve the trunk muscles. Their detection in the course of the evolution of a specific neoplasia testifies to their aggressiveness and portends an unfavorable prognosis. The data in our series confirm that in the literature regarding the underlying primary tumors and anatomical sites involved by MMs.

Solitary biceps muscle metastasis from breast cancer

Although direct muscle invasion by carcinoma is well recognised, skeletal muscle metastases are rare. Breast cancer very rarely metastasises to skeletal muscles. We present a case of breast cancer that metastasised to the biceps muscle. The woman developed breast cancer in 1990 and then developed axillary subcutaneous metastasis in 2001. In 2015, she presented with pain in the left forearm extending to the hand. Initial imaging showed no abnormalities, but the positron emission tomography-CT scanning revealed a hot spot in the left biceps muscle. Additionally, the nerve conduction study showed feature of carpal tunnel syndrome. The hot spot was deemed inconclusive in the view of normal CT and MRI scans, and the patient was treated with carpal tunnel decompression. A few months later, the patient developed a lump in the left biceps muscle, which appeared to be a metastatic lesion from her primary breast cancer. The patient was treated with radiotherapy and responded satisfactorily.

A Unique Case of Muscle-Invasive Metastatic Breast Cancer Mimicking Myositis

Breast cancer rarely metastasizes to the muscles, and it is even more unusual for this phenomenon to result in airway compromise. We present a unique case of an 84-year-old female who presented with neck swelling and upper airway obstruction due to metastatic breast cancer invading the sternocleidomastoid muscles. After establishing the diagnosis and discussing possible treatment options, the patient elected for antiestrogen therapy, palliative tracheostomy, radiation therapy, and hospice services.