SESSION TITLE: Lung Cancer Student/Resident Case Report Posters
SESSION TYPE: Student/Resident Case Report Poster
PRESENTED ON: Tuesday, October 27, 2015 at 01:30 PM - 02:30 PM
INTRODUCTION: Combined Small Cell Carcinoma (C-SCLC) with squamous admixture is very uncommon. It is a difficult subtype to diagnose bronchoscopically. Limited existing data on C-SCLC are found exclusively in the pathology and oncology literature.
CASE PRESENTATION: A 65-year-old male smoker presented with a new generalized tonic-clonic seizure. Vital signs and cardiopulmonary examination were normal. Initially he was awake, alert, and oriented. There were no focal neurological findings. The portable chest radiograph was unremarkable. Head computerized tomography (CT) revealed no acute process. Subsequently, his level of consciousness deteriorated, leading to endotracheal intubation for impaired secretion handling. Lumbar puncture yielded a mild lymphocytic pleocytosis with eventual negative cultures and cytology. Magnetic resonance imaging of the brain did not reveal any focal lesions or leptomeningeal enhancement. Electroencephalography was normal. Out of concern for a paraneoplastic encephalitis, cerebrospinal fluid (CSF) was sent for anti-Hu antibodies and CT of the chest was performed, the latter significant for intrathoracic lymphadenopathy. At bronchoscopy, multiple endobronchial masses were visualized and biopsied. Histology revealed small cell neuroendocrine carcinoma with interspersed foci of squamous differentiation (Figure 1), leading to the diagnosis of C-SCLC. Positive staining for synaptophysin and chromogranin was observed within the small cell component; the islets of squamous histology stained positive for CK903. Fluorescence was detected by enzyme-linked immunosorbent assay of CSF for anti-Hu antibodies, but the confirmatory Western blot was negative.
DISCUSSION: The reported incidence of C-SCLC ranges from 2% to 28% of all Small Cell Carcinoma (SCC). However, the majority of these represent combinations with large cell carcinoma. The squamous variety constitutes a small fraction of all C-SCLC cases and an even smaller percentage of SCC overall. The squamous component usually occupies only about 5% of the entire tumor, so it may not be sampled in the course of bronchoscopic biopsy. This could have important implications in light of evidence that prognosis of C-SCLC may be superior to that of pure SCC. The behavior of C-SCLC also tends to be closer to that of non-small cell carcinoma, namely presentation at an earlier stage and consequent greater resectability. Of note, the finding of endobronchial disease in our patient was much more reminiscent of pure squamous cell carcinoma than of pure SCC. Unresectable cases are treated with platinum-based chemotherapy with or without radiation.
CONCLUSIONS: The patient was successfully extubated prior to the initiation of sequential chemotherapy and radiation. He ultimately succumbed to his malignancy 10 months after diagnosis.
Reference #1: Babakoohi S, Fu P, Yang M, Linden PA, Dowlati A. Combined SCLC clinical and pathologic characteristics. Clin Lung Cancer. 2013 Mar;14(2):113-9.
DISCLOSURE: The following authors have nothing to disclose: Viral Gandhi, Elizabeth Awerbuch, Anatoly Leytin, Oleg Epelbaum
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