An Innocent Appearing Subcutaneous Nodule Diagnoses a Small Cell Lung Cancer in a Never-Smoker Female

Lung cancer among never-smokers is recognized as the 7th most common cause of cancer death globally. Adenocarcinoma is the most commonly reported histology. Small cell lung cancer (SCLC) has the strongest association with smoking and is rarely reported in never-smokers. Although lung cancer in never-smokers is more common in women, the overall incidence of SCLC in female never-smokers still remains low. Soft tissue metastases from any cancer are rare with an overall prevalence of 1.8%. Soft tissue metastases from lung primary are uncommon, mostly from adenocarcinoma, and portend a poor prognosis. Cutaneous metastases from SCLC are exceptionally rare with reported incidence of 0.3% to 0.8%. We believe ours is the first reported case of SCLC presenting as subcutaneous nodule, in a never-smoker, otherwise asymptomatic female. The diagnosis of SCLC was made incidentally by the excisional biopsy of the subcutaneous nodule. Subsequent CT chest and PET scan revealed a hypermetabolic right lower lobe spiculated lung mass with adrenal and liver involvement. Platinum and etoposide chemotherapy with prophylactic cranial irradiation was initiated for advanced SCLC, and she required further irinotecan and taxol for subsequent pancreatic and adrenal metastases. With continued deterioration, she died approximately 36 months from diagnosis, while under hospice care. 1. Introduction Lung cancer in never-smokers is increasingly being recognized as a distinct entity and ranks as the seventh most common cause of cancer death globally [1, 2]. Worldwide, 15% of men and 53% of women with lung cancer are never-smokers [2]. Adenocarcinoma is the most commonly reported histology in never-smokers [1, 2]. Recognized as an entity distinct from other lung cancers in 1926 by Dr. W. G. Bernard, small cell lung cancer (SCLC) accounts for 15% of annual lung cancers in the USA and is known to have the strongest association with tobacco use. More than 95% occur in smokers, with 95% fatality [3]. Small cell lung cancer in never-smokers is rarely reported. Soft tissue metastases from lung cancer are uncommon with reported overall prevalence of 2.3% [4], and rarely reported from SCLC. We report the first case of SCLC in a never-smoker woman presenting as subcutaneous nodule. 2. Case Presentation A 54-year-old woman presented with a two-month history of an enlarging, slightly painful left flank nodule. There was no preceding history of trauma or insect bite to the involved region. She denied fever, chills, rash, cough, shortness of breath, hemoptysis, mouth ulcers, arthralgias, dysuria, or