Brown tumors of the femur and pelvis secondary to a parathyroid carcinoma: Report of one case / Tumores pardos de fémur y pelvis secundarios a carcinoma de paratiroides: Informe de un caso

ABSTRACT

Brown tumors result from excess osteoclast activity and consist of collections of osteoclasts intermixed with fibrous tissue and poorly mineralized woven bone. They are secondary to hyperparathyroidism (HPT). Their incidence is higher in primary than in secondary hyperparathyroidism. We report a 69 years-old male, admitted in a state of confusion, lethargy and bedridden, with a pathological fracture of the femur caused by a brown tumor. The laboratory examination revealed a hypercalcemia (8.85 mEq/L), with high levels of ionized Ca (5.48mEq/L), serum alkaline phosphatases (416 U/L) and serum parathormone (120 pg/mL). Ultrasound examination of the neck showed a large parathyroid tumor, probably corresponding to a carcinoma. A primary HPT was diagnosed. The patient was hydrated and high doses of diuretics and bisphosphonates were administered. After correction of serum calcium and neurologic symptoms, the patient was operated, performing an extensive resection of the tumor. The pathology report confirmed the diagnosis of parathyroid carcinoma.

RESUMEN

Los tumores pardos son una consecuencia de una actividad osteoclástica excesiva y consisten en osteoclastos mezclados con tejido fibroso y tejido óseo mal mineralizado. Son secundarios a hiperparatiroidismo y más comunes en hiperparatiroidismo primario. Informamos de un hombre de 69 años que ingresa confuso y letárgico con una fractura patológica del fémur causada por un tumor pardo. El laboratorio mostró hipercalcemia de 8,85 mEq/L, fosfatasas alcalinas de 416 U/L y parathormona de 120 pg/mL. La ecografía del cuello mostró un tumor paratiroideo sospechoso de carcinoma. Se diagnosticó un hiperparatiroidismo primario. El paciente se hidrató y estabilizó con diuréticos y bifosfonatos. Una vez estabilizado, se operó efectuando una extensa resección del tumor. El estudio anatomopatológico confirmó el diagnóstico de cáncer de paratiroides.