Upper Tract Urothelial Carcinoma Complicated by Skeletal Muscle Metastases

Abstract

Urothelial carcinoma typically metastasizes via a lymphatic route to sites such as lymph nodes, bone, and liver. As in other malignancies, metastasis to skeletal muscle is rare. We present a case of a 66-year-old male with severe muscular pain after diagnosis of upper tract urothelial carcinoma, who was found to have extensive metastasis to skeletal muscles including gluteal, sternocleidomastoid, deltoid, vastus lateralis, and gastrocnemius muscles. Literature review demonstrated 18 previously reported cases of urothelial cell carcinoma with skeletal muscle metastasis, all male and all with bladder involvement. This case emphasizes the importance of thoroughly evaluating all muscular pain in patients with a history of malignancy as it may represent skeletal muscle metastasis with an associated increase in morbidity and mortality.

Keywords: JAK2; Skeletal muscle metastasis; Upper tract urothelial carcinoma; Urothelial carcinoma.

Figure 1

Widespread intramuscular metastases, axial views, seen in areas of increased uptake depicted with warmer colors. (a) Left gluteal muscle. (b) Right deltoid muscle. (c) Right vastus lateralis muscle. (d) Left calf musculature.

Figure 2

Widespread intramuscular metastases, coronal views, seen in areas of increased uptake depicted with warmer colors. (a) Left sternocleidomastoid, right deltoid, right vastus lateralis, and left thigh intramuscular metastases visible. (b) Left gluteal and left calf intramuscular metastases visible.