[Multiple insufficiency fractures (metatarsial, calcaneal and sacral) as the first manifestation of lung adenocarcinoma. A case report and literature review]

Abstract

Insufficiency fractures, or pathological fractures, are produced after minimal trauma or no prior trauma and normally affect weakened bone. Their presence should be suspected in fractures showing abnormal patterns, when several fractures occur in a short period of time and in those with no apparent or only minimal trauma. On confirmation of an insufficiency fracture, a differential diagnosis should be made between tumoral and metastatic fractures if there is a history of underlying primary malignancy. The epidemiology of lung cancer has changed due to women's adoption of smoking. In women, the most frequent type of lung cancer is adenocarcinoma, which is less aggressive and has lower mortality, with 5-year survival of 9.5%. Consequently, in Spain, 44% of pulmonary nodules are due to adenocarcinomas. Therefore, all solitary pulmonary nodules should be followed-up for at least 5 years. A history of solitary pulmonary nodule is found in one out of every 1,000 x-rays. However, in patients younger than 35 years, only 1% is malignant. In persons with a history of malignancy and age older than 35 years, this percentage increases to 68%. Size larger than 3cm increases the percentage of malignancy to up to 93%. Therefore, in female smokers older than 50 years with a history of solitary pulmonary nodule, the nodule should be considered malignant until demonstrated otherwise. We report for the first time in Spain the case of a woman with risk factors (smoking, age older than 50 years, with a 3-cm solitary pulmonary nodule that showed no significant growth in 3 years) who had multiple insufficiency fractures in a short period of time. Rehabilitation therapy was unsuccessful and the patient underwent investigation for malignancy. Unfortunately, histopathological study confirmed that the fractures were the initial manifestation of lung adenocarcinoma.

Keywords: Adenocarcinoma; Cáncer de pulmón; Fracturas por estrés; Fracturas por insuficiencia; Insufficiency fractures; Lung cancer; Nódulo pulmonar solitario; Paraneoplastic syndrome; Solitary pulmonary nodule; Stress fractures; Síndrome paraneoplásico.