Introduction: Case # 1

40 year old male status post living unrelated renal transplant in 2001, and undergoing immunosuppressive therapy. Presented to Emory University Hospital with an “abnormal chest CT”, performed at an outside institution in 2004. Three previews chest X-Rays were negative for pulmonary nodules.  Initial chest CT w/o contrast from outside institution demonstrated an ovoid, approximately 1 cm nodule in the right lower lobe, with a round, approximately 1 cm right lower lobe nodule located immediately inferiorly.

F-18 FDG PET/CT (See figures 1A. -1B.) at Emory demonstrated RLL nodules consistent with infection > likely than malignancy, in the setting of an immunocompromised patient.  Patient later underwent VATS biopsy which showed a necrotizing granuloma, consistent with a cryptococcal fungal infection.  Patient was started on appropriate anti-fungal therapy, and avoided further unnecessary invasive procedures.

Impression: 2 foci of hypermetabolic FDG uptake in the RLL (red arrows, max SUV 6.4).

Introduction: Case # 2

72 year old male status post cadaveric renal transplantation in 1998, undergoing evaluation workup for Large B-Cell Lymphoma with right tonsillar and pericardial involvement. Patient complaints of persistent right sided headache with increased intensity in the right maxillary sinus. F-18 FDG PET/CT (See figure 2A. - 2B.) demonstrated a hypermetabolic focus of FDG uptake in the right posterior maxillary sinus.  Differential diagnosis included infection vs. malignancy. Patient underwent CT guided Biopsy, followed by a right maxillary antrostomy. Pathology showed necrotizing inflammation and associated septate fungal hyphae, suggestive of Aspergillus species. Patient was started on appropriate therapy.

 

MIP Images demonstrating 2 foci of hypermetabolic FDG uptake in the RLL (red arrows), and transplanted kidney (blue arrow).

 

Impression: RLL nodules consistent with infection vs. malignancy in the setting of an immunocompromised patient (red arrows).

 

MIP image demonstrating a hypermetabolic focus of FDG uptake in the right posterior maxillary sinus (red arrow), and transplanted kidney (blue arrow).