A rare incidence of mandibular metastasis of papillary thyroid carcinoma: A case report and review of literature.

Papillary Thyroid Carcinoma (PTC) primarily metastasizes via regional lymphatics making its spread to the oral cavity exceedingly rare. Although this disease remains the most common endocrine malignancy, comprising roughly 85%-90% of all thyroid cancers, its occurrence within the oral cavity happens in less than 1% of oral malignancies. This study identifies a case involving a 77-year-old male with a history of well-differentiated PTC that was initially treated with a total thyroidectomy and adjuvant radioactive iodine. Five years after his initial treatment, surveillance imaging demonstrated a 3 cm expansile mass of the left mandible. An incisional biopsy then confirmed the diagnosis of metastatic PTC. A segmental resection of his mandible was completed with final reconstruction utilizing a fibula free flap. Given the limited number of cases involving metastatic spread of PTC to the oral cavity, a standardized treatment algorithm does not exist. Thus, this case serves to provide a documented report of this rare occurrence and to review literature that may help other clinicians treat patients with this malignancy type. There remains a need for future studies to create risk stratification models for patients with metastatic PTC that consider margin analysis, genetic characteristics, and risk factors to tailor individual treatment plans.

1,25-Dihydroxyvitamin D3 and 20-Hydroxyvitamin D3 Upregulate LAIR-1 and Attenuate Collagen Induced Arthritis.

Vitamin D plays a crucial role in regulation of the immune response. However, treatment of autoimmune diseases with 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] doses sufficient to be effective is prohibitive due to its calcemic and toxic effects. We use the collagen-induced arthritis (CIA) model to analyze the efficacy of the noncalcemic analog of vitamin D, 20S-hydroxyvitamin D3 [20S(OH)D3], as well as 1,25(OH)2D3, to attenuate arthritis and explore a potential mechanism of action. Mice fed a diet deficient in vitamin D developed a more severe arthritis characterized by enhanced secretion of T cell inflammatory cytokines, compared to mice fed a normal diet. The T cell inflammatory cytokines were effectively suppressed, however, by culture of the cells with 20S(OH)D3. Interestingly, one of the consequences of culture with 1,25(OH)2D3 or 20S(OH)D3, was upregulation of the natural inhibitory receptor leukocyte associated immunoglobulin-like receptor-1 (LAIR-1 or CD305). Polyclonal antibodies which activate LAIR-1 were also capable of attenuating arthritis. Moreover, oral therapy with active forms of vitamin D suppressed arthritis in LAIR-1 sufficient DR1 mice, but were ineffective in LAIR-1-/- deficient mice. Taken together, these data show that the effect of vitamin D on inflammation is at least, in part, mediated by LAIR-1 and that non-calcemic 20S(OH)D3 may be a promising therapeutic agent for the treatment of autoimmune diseases such as Rheumatoid Arthritis.