A 52-year-old man presented with a 6-month history of a soft tissue mass around the right axillary region, which appeared to be gradually increasing in size. He had no history of any major illness or trauma. Physical examination showed a nontender mass measuring 3×3 cm with a hard-elastic consistency that was palpable over the right axillary area. The mass was well demarcated from the surrounding structures, and no skin changes or neurovascular deficit were present.\nPlain radiographs showed soft tissue swelling with stippled calcification on the right medial axillary region (). Pathologic findings showed no osteolysis or cortical destruction around the lesion. CT also depicted calcification without an osteolytic lesion, and without thinning or expansion of the cortex of bone around the lesion (). In MR images, the peripheral area exhibited high intensity in both T1-weighted and T2-weighted images, whereas the central area exhibited low intensity in both (). Enhanced MRI revealed peripheral and mild speculated enhancement around the lesion, which was regarded to be due to calcification (). Chest and abdominal CT and a bone scan showed no evidence of metastasis.\nThe mass, lying on the latissimus dorsi muscle was excised. The tumor measured 3×3×3 cm in dimensions and appeared to be well-encapsulated. The longitudinal section of the resected mass revealed tan-white tissue with central and focal areas of hemorrhage and necrosis (). The histologic examination was consistent with a diagnosis of mesenchymal chondrosarcoma. The tumor consisted of undifferentiated small neoplastic cells, varying from round to spindle-shaped, and interspersed with well differentiated foci of cartilaginous tissue ().\nThe patient underwent a course of postoperative external beam radiation (6,000 cGy over 30 treatment sessions). At 1 year after surgery, the patient had remained free of local recurrence or metastasis.
A 47-year-old Iranian male patient referred to our outpatient clinic in the Imam Khomeini Hospital, Sari, with a palpable and painless mass in his left shoulder.\nThe patient did not complain about pain or weakness in this location. On examination, the mass was small, mobile, firm, and nontender located in the soft tissue of left shoulder. The skin covering the mass was intact, and there was no ecchymosis and even erythema (). The shoulder range of motion had no functional impairment, and the patient was able to do the routine tasks with no neurovascular disturbance. Medically speaking, important clinical signs and symptoms such as fever, weight loss, and respiratory symptoms were not detected.\nThere was no visible fluctuation in this field, and it was estimated 0.5-1 cm in length and width. Tumor consistency was not similar to bone, and it seemed to be a soft tissue mass. The patient denied any history of trauma and also no significant family history was identified. Interestingly, the patient was operated by general surgeon 6 times because of relapses in a way the last one was 1.5 years ago. At the first time, the patient was referred to the outpatient clinic because of gradual mass enlargement. The patient was operated by wrong method as transverse approach in the lateral border of the shoulder ().\nIn the recent recurrence, chest X-ray showed no obvious lung or bone involvement ( and ). Magnetic resonance imaging (MRI) illustrated a small extraskeletal nodular lesion with ring enhancement and no bone involvement at subcutaneous fat on lateral aspect of shoulder measuring about 13 mm which could be due to a recurrence of the previous tumor ( and ). Unfortunately, no previous documentation such as MRI was found. Thus, this caused difficulty for interpretation of the course of the main disease.\nFirst, we decided to operate the tumor as an incisional biopsy because we were not sure about the nature of the lesion. An important note in this approach was limited access to the lesion because of an incorrect previous approach. Pathologic specimen confirmed the diagnosis of chondrosarcoma. Then, he underwent a wide resection of the lesion in the beach-chair position. In surgery, the five dense fibrotic and firm masses measuring from 0.5 to 2 cm and the middle part of deltoid muscle (because of involvement) were excised and sent to pathology ward. Microscopic examination showed infiltrative hypercellular islands of pleomorphic chondrocytes composed of enlarged cells with irregular hyperchromatic nuclei and inconspicuous cytoplasm which was compatible with the diagnosis of chondrosarcoma with free surgical margins ( and ). We should say that the diagnosis was based on the characteristic clinical, radiologic, and pathological criteria; moreover, it was confirmed by immunohistochemistry. Hence, after consulting with the oncologist, radiation therapy was done. We have followed the patient for 6 months after operation, and until now, no recurrence is recognized.