Usefulness of positron emission tomography in the differentiation between tumor and infectious lesions in pediatric oncology: a case report.
BACKGROUND
Sometimes, in pediatric oncology, it is difficult to differentiate the relapse of primary tumor from other diagnoses such as post-ischemic lesions or fungal abscess, without performing an organ biopsy. In addition, patients frequently are not under clinical conditions to be biopsied, mainly due to febrile neutropenia. A growing number of studies has focused on the use of Positron emission tomography/computed tomography with 18 Fluorodeoxyglucose ([(18)F]FDG-PET/CT) to distinguish tumor relapse from infectious lesions in patients with febrile neutropenia.


METHODS
This case report describes a 6 years-old girl with febrile neutropenia during the treatment of neuroblastoma. Blood culture showed Candida sp. Abdominal ultrasonography revealed multiple unspecific hypoechoic areas of variable sizes in spleen, which might be either tumor or Candida-induced abscesses. [(18)F]FDG-PET/CT was performed to help the diagnosis and revealed small splenic lesions highly suggestive of disseminated candidiasis. Patient was then treated with systemic antifungal agent. After the recovery from febrile neutropenia, a spleen biopsy was performed, confirming the diagnosis of fungal abscess. Due to the small size of lesions, modalities such as ultrasonography, CT and magnetic nuclear resonance were not able in distinguishing tumor relapse from infectious lesions.


CONCLUSIONS
This case provides an excellent example in which the use of [(18)F]FDG-PET/CT is valuable in helping to localize potential sites of disseminated fungal infection to be diagnosed within clinical context. [(18)F]FDG-PET /CT seems to have a role in the evaluation of pediatric patients with febrile neutropenia.
Pediatric Oncology Service, Clinics Hospital, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil. fernandatiburcio@yahoo.com.br.
Fernanda Rodrigues
FR
Tibúrcio
Pediatric Oncology Service, Clinics Hospital, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil. kesrodrigues@gmail.com.
Karla Emília
KE
de Sá Rodrigues
Center of Molecular Imaging, National Institute of Science and Technology of Molecular Medicine (INCT-MM), Belo Horizonte, MG, Brazil. hmmvasconcelos@gmail.com.
Hérika Martins Mendes
HM
Vasconcelos
Center of Molecular Imaging, National Institute of Science and Technology of Molecular Medicine (INCT-MM), Belo Horizonte, MG, Brazil. debora.m.miranda@gmail.com.
Débora Marques
DM
Miranda
Center of Molecular Imaging, National Institute of Science and Technology of Molecular Medicine (INCT-MM), Belo Horizonte, MG, Brazil. acssilva@hotmail.com.|Department of Pediatrics, Interdisciplinary Laboratory of Medical Investigation, Faculty of Medicine, UFMG, Avenida Alfredo Balena, 190, 2nd floor, room# 281, CEP: 30130-100, Belo Horizonte, Minas Gerais, Brazil. acssilva@hotmail.com.
Ana Cristina
AC
Simões e Silva
D000038:Abscess / Q000000981:diagnostic imaging* / Q000188:drug therapy; D000310:Adrenal Gland Neoplasms / Q000000981:diagnostic imaging*; D002177:Candidiasis / Q000000981:diagnostic imaging* / Q000188:drug therapy; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D064847:Multimodal Imaging; D009447:Neuroblastoma / Q000000981:diagnostic imaging*; D009503:Neutropenia / Q000150:complications; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D013158:Splenic Diseases / Q000000981:diagnostic imaging* / Q000188:drug therapy; D014057:Tomography, X-Ray Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18