Underlying Adenocarcinoma of the Lung Metastasizing to the Proximal Phalanx of the Foot Causing Complex Regional Pain Syndrome A Case Report .

We report an unusual case of adenocarcinoma of the lung metastasizing to the proximal phalanx of the third digit in a 56-year-old woman with overlying complex regional pain syndrome. The patient was initially treated for neuroma, fracture, and neuropathic pain with no improvement over a 4-month period before presenting to the emergency department for left third digit pain. Radiographic imaging showed substantial osteopenia and mottling; magnetic resonance imaging demonstrated an aggressive lesion to the proximal phalanx. The patient underwent excision of the lesion, revealing metastatic moderately differentiated adenocarcinoma.