title: Tumefactive foreign body giant cell reaction following high-pressure paint injection injury: A case report and review of literature.
abstract: High-pressure paint injection injury is an uncommon but well-described injury. The histologic features of long-term paint injection injury with retained material are less recognized. A 46-year-old male presented clinically as "recurrent giant cell tumor of tendon sheath." The right index finger demonstrated fusiform enlargement by a pigmented mass with diffuse infiltration into the soft tissue of the hand. Histologically the tumor showed multiple giant cells in a fibrotic stroma extending into the dermis. There were multiple types of foreign material including diffuse brown black pigment, weakly optically polarizing foreign material and white inclusions with a "train track" appearance. The cells were positive for CD68 and negative for S100 antigen. Further investigation revealed that the patient had a history of high-pressure paint injection injury to his digit 6 years prior. Foreign material injected under high pressure into tissues may result in a pseudo-neoplastic foreign body granulomatous reaction that can mimic giant cell tumor of tendon sheath. Our case demonstrates that this reaction can be florid and can have slow growth over years. A high index of suspicion, a good clinical history and careful examination can distinguish these 2 entities.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at Houston, Houston, Texas.
authors.forename: Shakuntala H
authors.initials: SH
authors.lastname: Mauzo
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at Houston, Houston, Texas.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Swaby
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at Houston, Houston, Texas.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Covinsky
mesh_terms: D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D005383:Finger Injuries / Q000378:metabolism / Q000473:pathology; D005385:Fingers / Q000473:pathology; D005549:Foreign-Body Reaction / Q000378:metabolism / Q000473:pathology; D000070779:Giant Cell Tumor of Tendon Sheath / Q000378:metabolism / Q000473:pathology; D015743:Giant Cells, Foreign-Body / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism; D010150:Paint; D009418:S100 Proteins / Q000378:metabolism; D012509:Sarcoma / Q000378:metabolism / Q000473:pathology; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D009363:Neoplasm Proteins; D009418:S100 Proteins; C067980:CD68 antigen, human; D000097382:CD68 Molecule
keywords: fibrohistiocytic proliferation; giant cell tumor of tendon sheath; paint injection injury; pseudoneoplasm