Mast cell involvement in fibrodysplasia ossificans progressiva.

Gannon FH, Glaser D, Caron R, Thompson LD, Shore EM, Kaplan FS.
Hum Pathol. 2001 Aug;32(8):842-8.
Fibrodysplasia ossificans progressiva (FOP) is a catastrophic genetic disorder of progressive heterotopic ossification associated with dysregulated production of bone morphogenetic protein 4 (BMP4), a potent osteogenic morphogen. Postnatal heterotopic ossification in FOP is often heralded by hectic episodes of severe post-traumatic connective tissue swelling and intramuscular edema, followed by an intense and highly angiogenic fibroproliferative mass. The abrupt appearance, intense size, and rapid intrafascial spread of the edematous preosseous fibroproliferative lesions implicate a dysregulated wound response mechanism and suggest that cells and mediators involved in inflammation and tissue repair may be conscripted in the growth and progression of FOP lesions. The central and coordinate role of inflammatory mast cells and their mediators in tissue edema, wound repair, fibrogenesis, angiogenesis, and tumor invasion prompted us to investigate the potential involvement of mast cells in the pathology of FOP lesions. We show that inflammatory mast cells are present at every stage of the development of FOP lesions and are most pronounced at the highly vascular fibroproliferative stage. Mast cell density at the periphery of FOP lesional tissue is 40- to 150-fold greater than in normal control skeletal muscle or in uninvolved skeletal muscle from FOP patients and 10- to 40-fold greater than in any other inflammatory myopathy examined. These findings document mobilization and activation of inflammatory mast cells in the pathology of FOP lesions and provide a novel and previously unrecognized target for pharmacologic intervention in this extremely disabling disease.
PubMed ID: 11521229
Article Size: 2 MB

Osteomyelitis.

Gannon FH, Thompson LD.
Ear Nose Throat J. 2005 Nov;84(11):694.
FIRST PARAGRAPH: The proper treatment and clinical management of osteomyelitis (bone infection) depend on a successful correlation of its clinical features with radiologic and pathologic findings. Diagnostic difficulties may arise, and the final arbiter is intraoperative culture. The importance of intraoperative culture obtained in a ‘sterile’ environment cannot be overemphasized.
PubMed ID: 16381128
Article Size: <1 MB

Traumatic fracture callus

Gannon FH, Thompson L.
Ear Nose Throat J. 2007 Apr;86(4):200
FIRST PARAGRAPH: Bones of the craniofacial region are frequently broken, traumatically or iatrogenically. Whereas traumatic fractures can be readily identified clinically and radiologically, they can represent a diagnostic challenge histologically. A short discussion about the histologic evolution of traumatic fractures will help a pathologist know what to expect histologically, based on the time frames of development. The repair process follows a predictable histologic evolution of five distinct phases: culatory, cellular, vascular, metabolic, and mechanical.
PubMed ID: 17500387
Article Size: <1 MB