RESUMO
OBJECTIVE: To evaluate bone mineral density (BMD) in children with Cushing disease before and after transphenoidal surgery (TSS). STUDY DESIGN: Hologic dual-energy x-ray absorptiometry (DXA) scans of 35 children with Cushing disease were analyzed retrospectively. Sixteen of the 35 patients had follow-up DXA scans performed 13 to 18 months after TSS. BMD and bone mineral apparent density (BMAD) for lumbar spine (LS) L1 to L4 and femoral neck (FN) were calculated. RESULTS: Preoperatively, 38% and 23% of patients had osteopenia of the LS and FN, respectively. Both BMD and BMAD Z-scores of the LS were worse than those for the FN (-1.60 +/- 1.37 versus -1.04 +/- 1.19, P = .003), and (-1.90 +/- 1.49 versus -0.06 +/- 1.90, P < .001); postoperative improvement in BMD and BMAD were more pronounced in LS than in the FN (0.84 +/- 0.88 versus 0.15 +/- 0.62, P<.001; and 0.73 +/- 1.13 versus -0.26 +/- 1.21, P = .015). Pubertal stage, cortisol levels, and length of disease had no effect on BMD. CONCLUSIONS: In children with Cushing disease, vertebral BMD was more severely affected than femoral BMD and this effect was independent of degree or duration of hypercortisolism. BMD for the LS improved significantly after TSS; osteopenia in this group may be reversible.
Assuntos
Densidade Óssea , Hipersecreção Hipofisária de ACTH/fisiopatologia , Absorciometria de Fóton , Adolescente , Criança , Síndrome de Cushing/fisiopatologia , Feminino , Fêmur/fisiopatologia , Humanos , Hidrocortisona/sangue , Hidrocortisona/urina , Masculino , Estudos Retrospectivos , Coluna Vertebral/fisiopatologiaRESUMO
Odontogenic myxomas are rare benign neoplasms affecting the jaw. Myxomas of bones and other sites occur as part of Carney complex (CNC), a multiple neoplasia syndrome caused by mutations in the PRKAR1A gene, which codes for the regulatory subunit of protein kinase A (PKA). In the present study, 17 odontogenic myxomas from patients without CNC were screened for PRKAR1A mutations and PRKAR1A protein expression by immunohistochemistry (IHC). Mutations of the coding region of the PRKAR1A gene were identified in 2 tumors; both these lesions showed no or significantly decreased immunostaining of PRKAR1A in the tumor compared to that in the surrounding normal tissue. One mutation (c.725C>A) led to a nonconservative amino acid substitution in a highly conserved area of the gene (A213D); the other was a single base-pair deletion that led to a frameshift (del774C) and a stop codon 11 amino acids downstream of the mutation site; both tumors were heterozygous for the respective mutations. Of the remaining tumors, 7 of the 15 without mutations showed almost no PRKAR1A in the tumor cells, whereas IHC showed that the protein was abundant in nontumorous cells. We concluded that PRKAR1A may be involved by its down-regulation in the pathogenesis of odontogenic myxomas caused by mutations and/or other genetic mechanisms. Of the sporadic, nonfamilial tumors associated with PRKAR1A mutations, the odontogenic type was the first myxomatous lesion found to harbor somatic PRKAR1A sequence changes.