Myxoid tumours of soft tissue: the so-called myxoid extracellular matrix is heterogeneous in composition.Histopathology. 2008 Mar;52(4):465-74.

AIM: Myxoid tumours of soft tissue are characterized by their so-called 'myxoid' extracellular matrix. The aim was to investigate the composition and possible function of this matrix which is poorly understood. METHODS AND RESULTS: Using Alcian Blue staining with and without pretreatment with hyaluronidase and application of the critical electrolyte concentration method followed by densitometry, the glycosaminoglycan composition of three different myxoid tumours was studied. The composition of glycosaminoglycans varied with tumour type and grade, despite their general characterization as myxoid tumours. Intramuscular myxoma contained similar amounts of the various glycosaminoglycans as grade I myxofibrosarcoma; grade III myxofibrosarcoma contained less hyaluronic acid and more heparan sulphate, whereas extraskeletal myxoid chondrosarcoma contained predominantly chondroitin-4 and -6 sulphates. Western blot identified albumin as a major protein in tumour lysates, and its presence in the extracellular matrix and cytoplasm of the majority of tumours was demonstrated by immunohistochemistry; production of albumin by the tumour cells was confirmed by quantitative polymerase chain reaction. CONCLUSIONS: The extracellular matrix of myxoid tumours of soft tissue has a heterogeneous composition consisting of, amongst others, glycosaminoglycans and albumin, which appear to play an active role in their morphogenesis.

Myxofibrosarcoma of the spermatic cord: a case report. Nippon Hinyokika Gakkai Zasshi. 2008 Mar;99(3):555-9.

A 77-year-old man visited our department with a painless mass in the left scrotum. He underwent left high orchiectomy with clinical diagnosis of testicular tumor. The tumor penetrated deeply into the internal inguinal ring. The tumor was resected as proximally as possible with positive surgical margin at the internal ring. Macroscopically, the left testis was intact in the resected specimen. Microscopic examination revealed that the tumor was consisted of myxoid stroma with spindle cells, and there was a large variation in histological findings. Immunohistchemical staining was positive with vimentin, and negative with alphaSMA, S-100, Myo D1, EMA, keratin, HMB45, and LCA. Accordingly, the tumor was diagnosed as myxofibrosarcoma, high-grade, of the spermatic cord. Postoperative CT scanning revealed multiple retroperitoneal lymph node metastases. He underwent radiation therapy, but soon developed lung metastases and pleural dissemination, and died 2 months after the operation. Myxofibrosarcoma, which had been called myxoid MFH is one of the most common soft tissue sarcomas. Myxofibrosarcoma or myxoid MFH of the spermatic cord is a rare disease. To our knowledge, only 7 cases have been reported in Japan to date.

Myxofibrosarcoma involving the external saphenous nerve: a case report. Acta Chir Belg. 2007 Jul-Aug;107(4):442-5.

Myxofibrosarcoma, also known as "myxoid malignant fibrous histiocytoma" is one of the most common soft tissue sarcomas in the extremities of adult patients. Most cases are characterized by a multinodular and/or infiltrative pattern with a tendency to infiltrate along fascial planes. We report a case of myxofibrosarcoma with an unusual presentation. Despite the clinical impression of a complete surgical resection, microscopic sarcomatous foci extended along the perineurium of the external saphenous nerve proximally up to 20 cm away from the main tumour. This unique case represents an extreme example of the locally agressive behaviour of soft tissue sarcomas and illustrates the microscopic tumour invasion along major nerves.