Imaging features of extraskeletal mesenchymal chondrosarcoma of the hand

Extraskeletal mesenchymal chondrosarcoma of the distal thumb: A case report

INTRODUCTION AND IMPORTANCE

Chondrosarcoma is the most common primary malignant bone tumor of the hand, Mesenchymal chondrosarcoma (MCS) is a rare subtype of chondrosarcoma, extraosseous mesenchymal chondrosarcoma (EMCS) is even rarer.

CASE PRESENTATION

We presented a case of primary EMCS involving the distal thumb in a 59-year-old man. The patient had abnormally grown nails and a higher skin temperature than the contralateral finger. After admission to our hospital, we found that the tumor has the possibility of malignant transformation, but imageological examinations did not reveal invasive bone lesions and calcification. Finally, due to the patient's strong desire to preserve the thumb, a conservative surgical approach was selected to preserve the patient's finger function, and histological examination indicated MCS.

CONCLUSION

EMCS is a highly malignant tumor with strong tendency of invasion and metastasis. Imaging is sometimes difficult to diagnose, and pathology is a necessary part of distinguishing between benign and malignant tumors. Operation is the major treatment to EMCS, meanwhile, adjuvant radiotherapy and chemotherapy also be effective. The overall prognosis is poor.

Primary extraskeletal myxoid chondrosarcoma of bone: Report of three cases and review of the literature

Extraskeletal myxoid chondrosarcoma is a rare neoplasm of soft tissue. The usual location is in deep parts of the proximal extremities and limb girdles in middle-aged adults. The bone location as primary location is extremely rare and few cases are reported. We present three cases arising in bone with molecular confirmation using both RT-PCR and FISH analysis. Patients include two men and one woman with an age of 62, 69 and 73 years old. The mean size of the lesion was 13cm (range 8-18cm). Tumors arose in the iliac bone in two cases and in the proximal humerus in the other case. At time of diagnosis the three cases show bone cortex and soft tissue involvement. On imaging, lesions have a lobular pattern, are purely lytic, but take up contrast medium after injection. Two patients are alive with disease (local recurrence and lung metastasis) after five years and five years and six months, respectively and one patient died of disease two years after the diagnosis. The primary extraskeletal myxoid chondrosarcoma of bone seems to have a more aggressive behavior than the soft tissue counterpart. The molecular confirmation of diagnosis using RT-PCR is necessary to do the differential diagnosis with other entities, in particular with myoepithelioma that shows similar morphological features and EWSR1 and FUS genes rearrangement.

A diagnostic approach to popliteal fossa masses

There is a myriad of potential mass lesions that occur in the popliteal fossa, which present as palpable masses or are found incidentally on imaging. With a thorough knowledge and understanding of the appearances and locations of these different entities, one can narrow the differential diagnoses in the majority of cases. This will eliminate unnecessary additional investigations and enable a more rapid management. We present a review of frequently encountered and less common entities using an anatomical sieve, with the aim of providing a diagnostic approach to popliteal fossa masses.