Low-grade abdominopelvic sarcoma with myofibroblastic features (low-grade myofibroblastic sarcoma): Clinicopathological, immunohistochemical, molecular genetic and ultrastructural study of two cases with literature review

Institute of Pathology, Nuremberg Clinic Centre, Nuremberg, Germany.
Journal of clinical pathology (Impact Factor: 2.92). 04/2008; 61(3):301-6. DOI: 10.1136/jcp.2007.048561
Source: PubMed


Low-grade myofibroblastic sarcoma (LGMS) represents a rare soft tissue neoplasm with a predilection for the head and neck. Intra-abdominal LGMS are rare with only four unequivocal examples reported so far. Two further cases in females in their 60s and 70s are analysed here.
Immunohistochemical stains were applied on fresh-cut sections using the avidin-biotin complex method and the following antibodies: vimentin, alpha-SMA, desmin, h-caldesmon, S-100, CD117, CD34, fibronectin, HMB45, Pan-keratin, Ki-67, beta-catenin, MDM2, PDGFRalpha, PDGFRbeta and ALK-1. Genomic DNA was isolated from microdissected formalin-fixed paraffin-embedded tumour tissue and examined for KIT and PDGFRA mutations by PCR and direct sequencing of KIT and PDGFRA. Ultrastructural studies were also performed.
The tumours arose in the mesentery and the pelvic peritoneum. Both revealed features intermediate between conventional fibrosarcoma and leiomyosarcoma with fascicles of spindled, stellated or plump cells possessing fusiform indented vesicular nuclei and pale eosinophilic cytoplasm. Mitotic activity ranged from 1 to 15 per 10 HPFs. The tumour cells strongly expressed vimentin, variably alpha-smooth muscle actin and fibronectin, but were negative for CD117, S-100, desmin, h-caldesmon, beta-catenin, ALK-1, MDM2, PDGFRalpha and PDGFRbeta. One tumour showed a weak expression of CD34. Molecular analysis revealed a wild-type KIT, exons 9, 11 and 13, and PDGFRA, exons 12 and 18. The patients developed multiple peritoneal recurrences at 5, 13 and 25 months, and 10, 19, 25 and 32 months, and were alive at 25 and 32 months, respectively. Distant metastases were not detected.
Abdominopelvic LGMS follows a more aggressive clinical course characterised by a higher propensity for local recurrence, contrasting their more superficially located counterparts. LGMS may mimic a variety of benign and low-grade malignant neoplasms and might be under-recognised.

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Available from: Andreas Gaumann, Feb 21, 2015
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    • "LGMS has infiltrative characteristics, and some cases have shown lesions with compression of the surrounding tissues (Montgomery et al., 2001). The recurrence rate in a large series was reported as 40% (24 out of 60 patients), and distant recurrence was rare (Meng et al., 2007; Mentzel et al., 1998; Montgomery et al., 2001; Qiu et al., 2008; Agaimy et al., 2008). Adjuvant chemotherapy or radiation therapy was conducted in some patients, but the therapeutic effect was unclear (Meng et al., 2007; Mentzel et al., 1998; Montgomery et al., 2001). "
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    Gynecologic Oncology Reports 08/2013; 5:34–36. DOI:10.1016/j.gynor.2013.03.006
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    • "samples were punched from formalin-fixed, paraffin-embedded tissue blocks and processed for electron microscopy, as described previously [2]. "
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    ABSTRACT: Low-grade myofibroblastic sarcoma is a recently characterized tumor showing features of myofibroblastic differentiation that is part of the spectrum of malignant mesenchymal tumors. This extremely rare type of tumor occurs most commonly in superficial locations. The case we describe herein is that of a 60-year-old man with two large hepatic masses. The patient’s tumor was removed radically through an incision due to the inconclusive imaging findings. Follow-up computed tomography showed no recurrence and metastasis after 37 months, suggesting that enucleation was adequate for tumor eradication. To our knowledge, this is the first reported case of low-grade myofibroblastic sarcoma in the liver in the English language literature.
    Clinical Oncology and Cancer Research 12/2011; 8(4). DOI:10.1007/s11805-011-0590-8
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