Comparative immunohistochemical expression of RANK, RANKL and OPG in radicular and dentigerous cysts.

OBJECTIVE: Receptor activator of nuclear factor-κB (RANK), RANK ligand (RANKL) and osteoprotegerin (OPG) are members of the superfamily of ligands and receptors of tumour necrosis factor family involved in bone metabolism. The formation, differentiation and activity of osteoclasts are regulated by these proteins. To clarify the roles of osteoclast regulatory factors in cystic expansion of odontogenic cysts, expression of these proteins were analysed in radicular and dentigerous cysts. DESIGN: The immunohistochemistry expression of these biomarkers were evaluated and measured in lining epithelium and fibrous capsule of the radicular (n=20) and dentigerous cysts (n=20). RESULTS: A similar expression in lining epithelium was observed in the lesions. The fibrous capsule of dentigerous cyst showed a higher content of RANK-positive and RANKL-positive cells than fibrous capsule of radicular cyst. In the lining epithelium the RANKL/OPG ratio showed higher numbers of OPG-positive than RANKL-positive cells, whereas fibrous capsule of the cysts had a tendency to present a similar expression (OPG=RANKL). CONCLUSION: Ours findings indicate the presence of RANK, RANKL and OPG in cysts. Moreover, increased expression of OPG compared to RANKL in the lining epithelium could contribute to the differential bone resorption activity in theses lesions.

Familial malignant osteopetrosis in children: a case report.

The clinical, radiological, pathological and laboratory findings of two brothers with autosomal recessive malignant osteopetrosis are presented. Our findings are similar to characteristics previously reported in the literature about patients with osteopetrosis. The 6-year-old male patient was pale and had petechiae on his arms and legs. He also had macrocephalia, splenomegaly, severe pancytopenia, genu valgus, hypocalcemia, amaurosis, cessation of physical development, generalized bone sclerosis and recurrent infections with a history of multiple incidences of acute otitis media. Generalized bone sclerosis and irregular sclerosis of the maxilla and mandible were seen on radiographs. The oral mucosa was apparently normal but permanent tooth eruption was delayed although there was early loss of deciduous teeth. The recommended treatment was blood transfusion and therapy with antibiotics when necessary; a bone marrow transplant was not possible due to lack of a compatible donor.

Imaging modality correlations of an odontogenic keratocyst in the nevoid basal cell carcinoma syndrome: a family case report.

Multiple maxillary and mandibular cysts are principle features of nevoid basal cell carcinoma syndrome (NBCCS; Gorlin-Goltz syndrome). We present a family case report of NBCCS with odontogenic keratocyst where the findings on plain films, CT, clinical, and histopathologic examinations are compared and analyzed. The systemic manifestations included frontal bossing, odontogenic keratocyst, ectopic calcification in 1 patient, and bifid rib in 1 patient. CT examination displayed aspects of bone morphology not visible on the plain films. Odontogenic keratocyst diagnosis was confirmed by histopathological examination. The features identified by these combined clinical, imaging, and histologic findings are helpful in identifying an NBCCS patient, distinguishing keratocyst from others cysts or neoplasic lesions, and can therefore influence surgical management. NBCCS is a rare autosomal dominant cancer predisposition syndrome, which is important to recognize when a patient has multiple odontogenic keratocysts, because lifelong monitoring is essential for patient management.

Investigation of the GSalpha gene in the diagnosis of fibrous dysplasia.

Fibrous dysplasia is a benign fibro-osseous disease of bone and its etiology has been previously established. Activating mutations in the gene that encodes the alpha subunit of stimulatory G protein (G(S)alpha) has been described in monostotic and polyostotic fibrous dysplasia and in the McCune-Albright syndrome. The present report describes a patient with monostotic fibrous dysplasia which diagnosis was confirmed by sequencing of the G(S)alpha gene, demonstrating a heterozygous missense mutation on codon 201 (201C --> T). Due to the high prevalence of G(S)alpha gene mutations in fibrous dysplasia in contrast to other benign and malignant fibrous-osseous lesions, mutational analysis are an additional and helpful parameter for the diagnosis of fibrous dysplasia in selected cases.