SESSION TYPE: Cancer Student/Resident Case Report Posters
PRESENTED ON: Tuesday, October 23, 2012 at 01:30 PM - 02:30 PM
INTRODUCTION: While fludeoxyglucose-avid lung nodules often represent cancer, a broader differential diagnosis must be considered.
CASE PRESENTATION: A 74 year old woman presented with multiple, progressive symptoms of lower motor neuron leg weakness, left ptosis, papular rash on the extremities, weight loss and a fludeoxyglucose-avid lung nodule. Past medical history was significant for malignant melanoma 11 years prior, colon cancer 8 years prior, and hypertension. She was a lifetime non-smoker. Her only medication was metoprolol. On physical examination, vital signs, cardiac and pulmonary systems were unremarkable. There was no lymphadenopathy or hepatosplenomegaly. Neurologic examination revealed a left ptosis and 4+/5 weakness and decreased sensation to light touch in the bilateral lower extremities with a distal, symmetric distribution. Multiple non-tender erythematous papules over the arms and legs were noted. Complete blood count, serum creatinine and urinalysis were unremarkable. Carcinoembryonic antigen level, anti-nuclear antibody, anti-neutrophil cytoplasmic antibodies (ANCA), erythrocyte sedimentation rate and C-reactive protein were normal. Computed tomography of the chest showed a spiculated 1.6 cm right lower lobe pulmonary nodule, and innumerable diffuse bilateral pulmonary nodules measuring up to 6 mm. Only the dominant nodule was found to be hypermetabolic on a subsequent positron emission tomography scan (standardized uptake value 8.6). A transthoracic needle aspiration of the lung nodule demonstrated a lymphohistiocytic infiltrate with poorly formed granulomas and necrosis. Grocott's methenamine silver and acid-fast bacillus stains were negative. No malignant cells were seen. Flow cytometry demonstrated no clonal proliferation, and Epstein-Barr virus (EBV) stains were negative. Multiple skin biopsies demonstrated an atypical lymphohistiocytic infiltrate with granulomatous features. A repeat biopsy of the same lung nodule revealed identical pathology. A diagnosis of probable ANCA-negative systemic vasculitis was made, with pulmonary, neurologic and cutaneous manifestations. The patient was initiated on corticosteroid therapy with significant improvement in her symptoms.
DISCUSSION: Lymphoma and related lymphoid granulomatosis are less likely given normal flow cytometry and the lack of EBV, respectively. Conversely, the lack of positive serum markers does not rule out vasculitis. Routine immunsuppression by corticosteroids may be inadequate in the treatment of lymphohistiocytic lung tumor. Aggressive efforts may be required to break the cycle of lymphocyte-histiocyte activation, potentially by cell-specific monoclonal antibodies.
CONCLUSIONS: Inflammatory lung tumors, although rare, may mimic malignant tumors both clinically and radiologically. Clinical suspicion and tissue biopsies are required for the diagnosis.
1) Brown KK. Pulmonary Vasculitis. Proc Am Thoracic Soc. 3(1): 48-57. 2006
DISCLOSURE: The following authors have nothing to disclose: Ryan Van Wert, Daya Upadhyay
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