title: Solitary fibrous tumour of the chest wall.
abstract: Extrapleural solitary fibrous tumours (SFTs) are rare tumours characterized by patternless spindle cells with haemangiopericytoma-like vascular spaces. Previously the tumours have been classified as haemangiopericytoma, an entity that is now considered obsolete. We report a case of extrapleural SFT arising in the soft tissue of the chest wall. The patient was a 31-year-old Malay lady presenting with a mobile swelling of the right chest wall for more than five years. During excision the tumour was noted to be well-circumscribed and yellowish in colour, giving an impression of lipoma. Microscopically, the tumour had patternless architecture, characterized by hypocellular and hypercellular areas. It was composed of uniform, spindle-shaped cells displaying oval nuclei, inconspicuous nucleoli, pale cytoplasm and indistinct cell borders. The mitotic count was 2 per 10 HPF. Branching, medium-sized thin-walled blood vessels in a haemangiopericytomatous growth pattern, some with hyalinised wall were identified. The neoplastic cells were immunoreactive to CD99 and CD34 and were non-immunoreactive to Desmin, Smooth Muscle Actin, S100 protein and EMA. We elucidate the challenges in diagnosing this tumour in this unusual location.
authors.affiliation: Universiti Putra Malaysia, Faculty of Medicine and Health Sciences, Department of Pathology, 43400 UPM Serdang, Selangor, Malaysia. norhafizahm@upm.edu.my.
authors.forename: N
authors.initials: N
authors.lastname: Mohtarrudin
authors.forename: Z
authors.initials: Z
authors.lastname: Nor Hanipah
authors.forename: N
authors.initials: N
authors.lastname: Mohd Dusa
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis; D001706:Biopsy; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008938:Mitosis; D054364:Solitary Fibrous Tumors / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D013899:Thoracic Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D035441:Thoracic Wall / Q000737:chemistry / Q000473:pathology* / Q000601:surgery
chemical_list: D014408:Biomarkers, Tumor