Metástasis musculares no sospechadas detectadas con 18F-FDG PET/TC / Unsuspected muscle metastases detected with 18F-FDG PET/CT Abstract

Objetivo: Evaluar la prevalencia de metástasis musculares (MM) no sospechadas en pacientes con enfermedad maligna conocida, estudiados con tomografía por emisión de positrones integrada con tomografía computada con flúor-18 deoxiglucosa (18F-FDG PET/TC). Materiales y métodos: Se analizaron retrospectivamente 2953 18F-FDG PET/TC, identificando las MM. Se registraron los tumores primarios, el número y localización de las MM y el SUV máximo en cada caso. Fueron incluidos pacientes oncológicos con histología conocida y múltiples lesiones secundarias. Se utilizó el examen 18F-FDG PET/TC como método de referencia para detectar metástasis. Resultados: Se identificaron MM en 33 pacientes (prevalencia: 1,12%) entre los 18 y 88 años de edad. Los tumores primarios incluyeron: riñón en 7 casos, mama en 5, melanoma en 4, pulmón en 3, ovario en 3, tiroides en 3, sarcomas en 3, región colorrectal en 2, vejiga en 2 y endometrio en 1. Se encontraron 96 MM en 33 pacientes: 24 en muslo, 15 en glúteo, 13 en pared torácica, 10 en psoasilíaco,10 en músculos paravertebrales, 7 en pared abdominal, 7 en pierna, 4 en brazo y 6 en otras localizaciones (pelvis, cuello, etc.). Las MM afectaban un solo músculo en 22/33 pacientes y varios en 11/33. El patrón de captación más frecuente fue el foco hipermetabólico, con SUV máximo entre 1,5 y 34. Discusión: Nuestra muestra incluye un número importante de casos comparada con la literatura y coincide con los hallazgos de otros autores en la incidencia y localización de las MM. Conclusión: Las MM son infrecuentes y pueden pasar inadvertidas. Es posible detectarlas con 18F-FDG PET/TC como focos hipercaptantes únicos o múltiples.

Objective: To assess the prevalence of unsuspected muscle metastases (MM) in patients with known malignant disease, examined with 18F-fuorodeoxyglucose positron emission tomography integrated with computed tomography (18F-FDG PET/CT). Materials and methods: A total of 2,953 18F-FDG PET/CT examinations were retrospectively analysed, looking for cases with MM. Primary neoplasm, number and location of MM and SUV max were recorded on each patient. Oncology patients with known histology and multiple secondary lesions were included. The 18F-FDG PET/CT was the reference method for detection of metastases. Results: MM were observed in 33 patients (prevalence: 1.12%) aged between 18 and 88 years. The primary tumours included: kidney in 7 cases, breast in 5, melanoma in 4, lung in 3, ovary in 3, thyroid in 3, sarcomas in 3, colorectal in 2, bladder in 2, and endometrial in 1. A total of 96 MM were observed in 33 patients, and located in: thigh muscles 24, gluteal 15, chest wall 13, iliopsoas 10, paravertebral muscles 10, abdominal wall 7, leg 7, arm 4, and other locations 6 (pelvis, neck, etc.). MM affected only one muscle in 22/33 patients and several muscles in 11/33. Hypermetabolic focus was the most frequent uptake pattern, with SUV max between 1.5 and 34. Discussion: Our series has a significant number of cases, and is consistent with other authors on the incidence and location of MM. Conclusion: MM are uncommon and may be overlooked. MM may be detected with 18F-FDG PET/CT as single or multiple hypermetabolic foci.

Skeletal muscle metastasis from carcinoma cervix: a case report / 부인종양

Cervical cancer is the most common malignancy in Indian women. Cervical cancer usually spread by local extension and through the lymphatics to the retroperitoneal lymph nodes. Direct invasion of muscles by primary growth is more common than by metastatic involvement. We present a case of carcinoma of the cervix post radiotherapy to pelvis who on follow up presented with biceps muscle metastases as the initial sign of disseminated disease.

Metastases to Skeletal Muscles from Non-Small Cell Lung Cancer Demonstrated by 18F-FDG PET/CT

Hematogenous metastases to skeletal muscles are extremely rare metastases that may present as painful masses in the proximal skeletal muscles. The reasons for the rarity of metastatic tumors in skeletal muscle are not clear. However, the whole body coverage and high sensitivity of 18F-FDG PET/CT make it suitable for evaluating distant metastasis. We report here the findings of 18F-FDG PET/CT in a 66-year-old female with non-small cell lung cancer (adenocarcinoma) and multiple metastases to skeletal muscles