Atypical Hypertrophic Osteoarthropathy as a Presenting Complaint in a Non-Smoker

Abstract

A 70-year-old non-smoker initially presented to accident and emergency with a painful left foot. This was an atypical presentation of hypertrophic osteoarthropathy (HPOA) secondary to grade 4 adenocarcinoma of the lung, highlighting the importance of routine chest x-ray in clinical assessment of atypical bone pain. Diagnosis was made using an isotope bone scan, the most sensitive method for detecting HPOA. The tumour and HPOA symptoms responded well to the first line chemotherapy regimen of cisplatin and pemetrexed. This supports the current understanding that treatment of the primary lung lesion will treat HPOA. The mechanism of this action is hypothesised to be by reduction of endogenous growth factor production, either by reduction in cell numbers producing the factor or direct inhibition of factor production: VEGF is emerging as the predominant growth factor causing HPOA. We believe the mechanism of cisplatin action on HPOA symptoms may be two fold; firstly, by direct reduction in VEGF secreting tumour bulk and secondly, by reduction of VEGF transcription. After disease progression of the lung tumours and recurrence of HPOA symptoms the patient received second line docetaxel. HPOA symptoms were unchanged but the chemotherapy stabilised the tumours. This lack of effect on HPOA symptoms may be due to a lack of tumour reduction or more speculatively the lack of suppression of VEGF transcription. HPOA symptoms were significantly improved when the patient was started on octreotide and current studies suggest that VEGF inhibition may be the mechanism of octretotides effect.




J Med Cases. 2013;4(4):204-207
doi: https://doi.org/10.4021/jmc1057w