Superficial collagenous fibroma: immunohistochemical, ultrastructural, and flow cytometric study of three cases, including one pemphigus vulgaris patient with a dermal mass

Desmoplastic fibroblastoma (collagenous fibroma): a case identified in the buccal mucosa

Desmoplastic fibroblastoma is a rare, benign, soft tissue tumor affecting mainly the subcutaneous and muscle tissue. Only five cases identified in the oral cavity have been reported in prior literature. This article presents a case report of a 56-year-old man, with no previous history of trauma, who presented a slow-growing mass in the buccal mucosa. Histopathology and immunohistochemistry staining studies were performed, and a diagnosis of the desmoplastic fibroblastoma was made. The patient has been disease-free for one year.

Desmoplasia: not always a bad thing

Desmoplasia describes a histological pattern characterized by a hyalinized stroma and a minimal cellular infiltrate. In non-cutaneous neoplasms, this pattern of stromal response is classically associated with malignancy, whereas in cutaneous pathology, desmoplasia is observed in malignant as well as benign neoplasms. Given this, the obvious question is whether desmoplasia associated with a benign neoplasm is any different from that associated with malignant tumours. Is the stromal response a mere epiphenomenon, or does it actually contribute to the biological behaviour of the neoplasm? What happens at the tumour-host interface? Which molecules are involved in mediating the desmoplastic reaction pattern? This review is an attempt to answer these questions. Examples of benign and malignant cutaneous neoplasms associated with the desmoplastic reaction pattern will be included.

Collagenous fibroma (desmoplastic fibroblastoma) of the neck presenting with neurological symptoms

Collagenous fibromas are rare fibrous soft tissue tumours that usually arise in subcutaneous tissue or skeletal muscle at a variety of anatomical sites. These lesions commonly present as painless, slow-growing mobile masses. We describe a unique case of a 41-year-old woman presenting with a posterior neck swelling and longstanding history of severe ongoing pain in the right scapular region, shoulder and neck, weakness of the palmar grip and limited right lateral neck flexion and rotation. A history of trauma to the right neck in adolescence was noted. Histological analysis revealed a paucicellular lesion with spindle and stellate-shaped fibroblasts involving the cervical nerve roots, typical of collagenous fibroma. In a literature search on Medline and Pubmed, we found no reported cases of collagenous fibromas presenting with neurological symptoms. This report highlights the potential of these lesions to present with neurological symptoms due to infiltration of surrounding tissues, and that preceding trauma may contribute to the aetiology.

Collagenous fibroma of the deltoid muscle: clinical, surgical and histopathological aspects

We report the case of a 66-year-old woman with a tumorous swelling of the right shoulder of approximately 6 months' duration with morphological features consistent with desmoplastic fibroblastoma or collagenous fibroma, a benign fibrous soft tissue tumor with distinct clinico-pathological features. Clinical history, radiological and pathological findings are presented and other cases of collagenous fibroma with unusual location are discussed.

Desmoplastic fibroblastoma: a light and ultrastructural description of two cases

The authors report 2 cases of collagenous fibroma in which ultrastructural analysis revealed the presence of fibronexus junctions, markers of myofibroblastic differentiation, never described in this rare lesion before. The tumors occurred in the trapezius muscle and in the right arms of a 41 -year-old and a 25-year-old man. They were both intramuscular and showed sharp edges. Grossly, the excised masses were whitish and firm. Microscopically, they were both composed of stellate or spindle-shaped cells separated by a collagenous hypovascular and focally myxoid stroma. Mitotic figures and necrotic areas were not identified. Immunohistochemistry showed positivity for vimentin and focal positivity for smooth and human muscle actin, and flow cytometry showed the tumoral cells to be diploid.