PET-CT scan positive pulmonary nodule revealing histoplasmosis: a case report

Our medical staff identified a case of a forty-six years old Armed Force active duty female that presented with multiple systemic and pulmonary signs and symptoms, such as hemoptysis, arthralgias, chest pain and dyspnea after being exposed to a humid and old wooden building one year ago in the state of Georgia. Various imaging studies (cervical & thoracic x-rays and CT Scans), revealed diffuse small nodules at cervical & thoracic areas, osteolytic lesions and lymphadenopathy. Suspecting a malignant process, a PET-CT Scan was performed revealing a right lung lower lobe nodule consistent with a primary malignancy, metastatic disease, active infectious or inflammatory process. She underwent a CT-guided needle biopsy followed by an open thoracotomy. These results were negative for malignancy and positive for chronic granulomatous inflammatory process. Therefore, special immunologic stains were undertaken revealing a granulomatous process with Histoplasmosis capsulatum. This case was diagnosed in the most unusual manner, given the presenting symptoms and pathological findings which suggested a malignant process, later confirmed by multiple specialized imaging studies and tests. This presumptive diagnosis turned out to be an inflammatory/infectious (fungal) process. We must keep in mind that not all mass lesions encountered by special imaging studies should be considered malignant. This case exemplifies the need of clinicians to exercise strong clinical and critical thinking skills to consider the broad diagnostic possibilities of pulmonary nodules presenting as a malignancy.