No abstract

We present a case of extrapleural solitary fibrous tumor arising within the muscle, an unusual and hitherto-undescribed tumor lesion. A 42-year-old woman presented a painless mass in her left thigh. The lesion was depicted as an intramuscular mass that enhanced on both CT and MRI, showing quite rich tumor vascularity. The histological features of the tumor were spindle cell proliferation with various histological patterns, typical fibrocollagenous background, and positive immunoreactivity for CD-34.

In 1952, Christopherson et al. proposed that alveolar soft-part sarcoma (ASPS) was a distinct entity with unique clinical and pathological features. Since their report, its histogenesis has not been determined. In order to clarify the histogenesis of ASPS, a study using reverse transcription polymerase chain reaction using cDNAs from MyoD1 and myogenin, and the actin filament from human-skeletal-muscle-related mRNAs has been performed in 5 cases of ASPS. The expression of MyoD1 and myogenin was determined in 5 and 2 cases of the 5 cases, respectively. Moreover, expression of the many mRNAs from the actin filament of skeletal muscle was also found in ASPS. According to these findings, it is now postulated that ASPS is of skeletal muscle origin.

No abstract

Intraosseous ganglia occur most frequently in the long bones of the lower limbs, particularly in the medial malleolus of the tibia. They usually appear as radiographically well circumscribed juxta-articular cystic lesions, containing myxoid fibrous tissue histologically. Intraosseous ganglia in the hand are very rare. Most reported cases have involved the carpal bones, in particular the lunate and scaphoid. To our knowledge, the present case is the third report of an intraosseous ganglion appearing in the first metacarpal bone; it arose in a patient who had been on dialysis for 25 years, mimicking amyloidosis of bone.