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

Abstract

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.

Keywords: 18F-fluorodeoxyglucose; iliopsoas; muscular metastases; neoplasia; paraspinal; physiological uptakes; positron emission tomography/computed tomography.

Figure 1

A 67-year-old patient suffered from a high grade of neuroendocrine tumor. Recurrence detection report. (a) Fusion image in axial section shows reached muscle of the left diaphragmatic abutment. (b) Fusion image in axial section shows a secondary localization of the myocardium (localization of the apex proved by a cardiac magnetic resonance imaging)

Figure 2

Assessment report after radiochemotherapy for a 53-year-old patient with lung adenocarcinoma. (a) Sagittal sectional fusion image shows involved paravertebral muscle at the height of L1 (maximum standardized uptake value = 32.6). (b and c) Computed tomography and fusion images in axial sections for a metastasis in the left psoas muscle (maximum standardized uptake value = 37.1)

Figure 3

Fusion images in axial sections in a patient with a bronchial adenocarcinoma, showing, in addition to reached iliac bone, two hypermetabolic masses of secondary muscle localizations. (a) Hypermetabolic mass of the right psoas muscle with necrotic ametabolic center. (b) intercostal hypermetabolic focus at the height of K5–K6. Initial extension repor

Figure 4

Coronal sectional fusion image showing a reached muscle of the right popliteal fossa (maximum standardized uptake value = 23.4) which corresponds to a mass of tissue tone on the morphological image