case_images: PMC6588148_01
case_images: Clinical features: The lesion located in the posteromedial region of the left leg (a) pre-operative X-rays showed a nodular mass at the proximal third of the left leg (b) magnetic resonance imaging (MRI) (c) and vascular MRI (d) showed a posterolateral dislocation of the distal part of popliteal artery and tibioperoneal trunk, without alterations in canalization.
case_images: JOCR-9-74-g001.jpg
case_images: PMC6588148_01_JOCR-9-74-g001.jpg
case_images: F1
case_images: A 42-year-old woman presented at our observation with a 4-year history of a slow-growing, painful swelling on the posteromedial region of her left leg (Fig. 1a). X-rays evidenced the presence of a nodular mass at the proximal third of the left leg arising from the soft tissues next to the medial aspect of tibia (Fig. 1b); multiple calcific components were also observed. Subsequent magnetic resonance imaging (MRI) showed the presence of a 13 cm x 6 cm, 3 cm x 6 cm, 1 cm capsulated mass occupying soleus muscle, compressing, and displacing anteriorly gastrocnemius muscle (Fig. 1c). Moreover, the patient underwent vascular MRI of leg arteries which showed a posterolateral dislocation of the distal part of popliteal artery and tibioperoneal trunk (Fig. 1d), without alterations in canalization.
case_images: Surgical and histological images: En bloc excision of the tumor (a) gross examination of a well-circumscribed, nodular, white-gray, stiff mass (b) microscopic findings x120 (c) and x200 (d) showing that the lesion consisted in a multinodular growth with lobules of hyaline cartilage with a low cellularity and bland-looking chondrocytes (hematoxylin/eosin stain).
case_images: JOCR-9-74-g002.jpg
case_images: PMC6588148_01_JOCR-9-74-g002.jpg
case_images: F2
case_images: However, to exclude the possibility of chondrosarcoma, which is a common differential diagnosis, especially when dealing with small biopsies, a surgical excision of the entire tumor, including the capsule, was performed (Fig. 2a). Gross examination revealed a well-circumscribed, gray-white, nodular mass of 13 cm in greatest diameter (Fig. 2b). Histological examination showed an encapsulated lesion with multinodular growth, composed of the lobules of hyaline cartilage surrounded by mature adipose tissue (Fig. 2c).