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Postradiation cutaneous pleomorphic rhabdomyosarcoma with extracellular collagen deposits reminiscent of so‐called amianthoid fibers
Author(s) -
SabaterMarco Vicente,
Zapater Latorre Enrique,
Martorell Cebollada Miguel
Publication year - 2014
Publication title -
journal of cutaneous pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 75
eISSN - 1600-0560
pISSN - 0303-6987
DOI - 10.1111/cup.12282
Subject(s) - rhabdomyosarcoma , desmin , pathology , myogenin , vimentin , cd99 , extracellular matrix , immunohistochemistry , biology , sarcoma , medicine , anatomy , skeletal muscle , microbiology and biotechnology , myogenesis
Rhabdomyosarcoma is a malignant mesenchymal neoplasm that rarely presents as primary skin tumor. So‐called amianthoid fibers are hyalinized collagen mats that have been described in myofibroblastic tumors but not in rhabdomyosarcoma. A 65‐year‐old male developed a submandibular nodule 9 years after an oral squamous cell carcinoma, which had been treated with chemotherapy and radiotherapy. Histological examination of the nodule revealed a pleomorphic rhabdomyosarcoma with extracellular collagen deposits reminiscent of so‐called amianthoid fibers. By immunohistochemistry, the tumor cells were positive for vimentin, desmin, smooth muscle actin (SMA), muscle‐specific actin (MSA), CD10, CD56, CD99, β‐catenin and D2‐40. However, only 15–20% of the tumor cells were positive for myoglobin, MyoD1 and myf‐4/myogenin. We describe first so‐called amianthoid fibers harboring blood capillaries in a rhabdomyosarcoma, suggesting that they are rigid collagen structures that lead to tumor vascularization. The low expression for myogenic regulatory proteins and strong expression for other markers may be misleading and do not contribute to the diagnosis of rhabdomyosarcoma.