Title: A Case of Histoplasmosis Mimic Metastatic Esophageal Cancer
Abstract: SESSION TITLE: Student/Resident Case Report Poster - Imaging SESSION TYPE: Student/Resident Case Report Poster PRESENTED ON: Tuesday, October 25, 2016 at 01:30 PM - 02:30 PM INTRODUCTION: FDG (fluorodeoxyglucose) PET-CT is an important modality for characterizing, staging and restaging of esophageal cancer[1]. FDG as an analog of glucose is a nonspecific agent for tumor imaging. A focal esophageal FDG uptake on PET should bring up the differential diagnosis of esophageal cancer, metastatic disease, infection and inflammation[2]. The presence of lymphadenopathy follows the drainage pathway of esophageal cancer could be helpful. However, an infectious process may have similar appearance. The definite diagnosis relies on tissue biopsy. CASE PRESENTATION: 50 years old female was found to have a para-esophageal mass incidentally on CT for workup of hematuria. The mass is 2 x 3 cm on CT with central necrosis concerning for metastatic lymph node by CT finding. A questionable nodule is also seen in the esophagus on CT. A FDG PET shows intense focal FDG uptake in this area corresponding to the enlarged lymph node without abnormal uptake of esophagus. Patent underwent VATS and biopsy of para-esophageal mass after failed with EGD with biopsy. The pathology shows necrotizing granuloma with caseation suggestive of fungal infection especially histoplasmosis. Itraconazole was started after consult of infectious disease. On follow-up PET-CT, feasible response is noted on the mass reflected by significant decrease of FDG avidity on FDG PET. DISCUSSION: Histoplasmosis, a condition caused by histoplasma capsulatum, primary affects the pulmonary system and causes cavitating lesions. Histoplasmosis is likely to be a cause of false positive result for FDG PET evaluation of lung cancer[3]. Adrenal histoplasmosis is one of the most common adrenal granulomatous infections. Adrenal histoplasmosis should be considered as one of the differential diagnosis of focal adrenal uptake in area where histoplasmosis is endemic. CONCLUSIONS: Here we report a case of solitary lesion of histoplasmosis mimicking esophageal cancer without pulmonary or other evidence of histoplasmosis. A focal FDG uptake of fungal infection of esophagus could be as intense to mimic esophageal cancer therefore should always be in the differential diagnosis. Reference #1: Schmidt, T., et al., Value of functional imaging by PET in esophageal cancer. J Natl Compr Canc Netw, 2015. 13(2): p. 239-47. Reference #2: Sharma, P., et al., Potential role of 18F-FDG PET/CT in patients with fungal infections. AJR Am J Roentgenol, 2014. 203(1): p. 180-9. Reference #3: Croft, D.R., et al., FDG-PET imaging and the diagnosis of non-small cell lung cancer in a region of high histoplasmosis prevalence. Lung Cancer, 2002. 36(3): p. 297-301. DISCLOSURE: The following authors have nothing to disclose: yuyang zhang, Darko Pucar, Jayanth Keshavamurthy No Product/Research Disclosure Information