Gunjan Garg

INTRODUCTION: We undertook this prospective study to compare amino acid metabolism, glucose metabolism, and proliferation in primary and recurrent low grade gliomas using positron emission tomography (PET)/computed tomography with F-18 FDOPA, F-18 FDG, and F-18 FLT. METHODS: Fifteen patients with newly diagnosed or previously treated low grade gliomas (WHO grade I or II) were subjected to F-18-FDOPA, F-18 FDG, and F-18 FLT PET/computed tomography studies on consecutive days. This included 2 patients in remission as control subjects. Uptake of all the 3 tracers were analyzed visually and quantified using standardized uptake values and tumor to normal (T/N) ratios. The accuracy of all the 3 PET tracers in the detection of newly diagnosed and recurrent low grade gliomas was compared. RESULTS: F-18 FDOPA was positive in all cases of primary and recurrent low grade gliomas and negative in the patients in remission. Tumor was visualized on F-18 FDG in 7 of 13 cases, F-18-FLT was positive in 4 of 13 cases. Average tumor standardized uptake values max for F-18 FDOPA (5.75 +/- 4.9) and F-18 FLT (1.8 +/- 0.91) was lower than that of F-18 FDG (8.5 +/- 4.4). T/N ratios for F-18-FDOPA (2.3 +/- 0.51) and F-18 FLT (1.8 +/- 0.91) were higher than F-18 FDG (1.03 +/- 0.64) providing good image contrast for tumor detection in positive cases. CONCLUSION: F-18 FDOPA scan is superior to both F-18 FLT and F-18 FDG for visualization of primary and recurrent low grade gliomas. F-18-FLT should not be considered for evaluation of recurrent low grade gliomas.

Acquired ectopic splenic tissue is called splenosis, which is common after the history of trauma or surgical exploration. We present a rare case of intrahepatic splenosis in 36-year-old male patient mimicking a liver neoplasm on imaging however presented with left flank pain for 5 months and had remote history of splenectomy after splenic rupture from trauma. We discuss various imaging modalities and the role of various magnetic resonance imaging sequences and nuclear medicine examination. We also discuss the differentiating features to be kept to make the correct diagnosis along with a brief review of literature. We mentioned signal intensities of splenic lesions and normal signal intensity of spleen in different magnetic resonance imaging sequences and with high suspicion how we can diagnose splenosis and avoid unnecessary biopsy and its result related stress.

A 20-year-old man diagnosed as a case of desmoplastic cerebellar medulloblastoma had undergone shunting of the lateral ventricles and resection of the mass followed by postoperative irradiation to the entire neuraxis. There was evidence of residual disease in the posterior fossa on craniospinal MRI for which he had undergone cranial radiation and adjuvant chemotherapy. Two serial cranial MRI's (4 months apart) were done following this and though the lesion in the posterior fossa remained essentially the same with no evidence of progression the patient had a general decline in his ability to function and he was sent for a FDG-PET/CT study to evaluate for recurrent disease. The study revealed abnormal FDG uptake along the entire length of the thecal sac from the cervical to the lumbosacral level suggesting the possibility of metastasis. Spinal MRI with gadolinium contrast confirmed diffuse leptomeningeal metastasis. Thus FDG-PET/CT is a useful tool to evaluate for metastasis in medulloblastoma.

We report a case of a 68-year-old female who was a known case of diabetes mellitus and chronic liver disease and presented with complaints of dry cough and other constitutional symptoms since one month. During initial investigations, the patient was found to have peripheral blood eosinophilia. Upon investigating further,the patient was found to have mediastinal lymphadenopathy and fine-needle aspiration of mediastinal lymph nodes showed features of tuberculosis. The patient was started on anti-tubercular treatment and her eosinophil counts returned to normal levels. Correlation between eosinophilia and tuberculosis has not been established in classical literature. This case highlights the same association and raises awareness on this crucial finding. Coexistence of eosinophilia and tuberculosis in our patient is suggested since peripheral blood eosinophilia improved with anti-tubercular treatment. The exact pathogenesis of coexistence of tuberculosis and peripheral blood eosinophilia yet remains to be deciphered, but tissue pathology is mainly associated with the discharge of toxic eosinophil products.