solitary fdg avid liver lesion in oncological setting is often metastatic in nature . at the same time , such lesions are less likely to be of tuberculous etiology . however , we report an unusual scenario in a 15 year old boy , of a solitary liver lesion in a case of round cell tumor , which on follow up imaging , turned out to be hepatic tuberculosis . a 15-year - old boy , presented with a right leg swelling , which increased in size over 2 months . radiograph of right lower limb showed a lytic sclerotic mass in proximal meta - diaphysis of right fibula , which on biopsy was suggestive of ewing 's sarcoma . whole body 18f - fluoro - deoxyglucose positron emission tomography / computed tomography ( fdg pet / ct ) was performed as a part of staging work - up . maximum intensity projection ( mip ) image [ figure 1a ] showed intense focus of tracer uptake in the right leg ( arrow ) and liver ( arrow - head ) . axial fused pet / ct images revealed intense tracer uptake in destructive lytic - sclerotic soft tissue mass in upper end of right fibula , with a maximum standardized uptake value ( max suv in millicurie / kilogram of body weight ) of 7.8 . an intense solitary focus of fdg uptake was seen in hypodense lesion in caudate lobe of liver [ figure 1c - arrow ] , which was presumed to be metastatic on the basis of imaging findings . follow - up fdg pet / ct study after treatment completion showed complete regression of tracer concentration at primary site in tibia on mip image [ figure 1b - arrow ] , as well as reduction in size of the soft tissue mass with post treatment healing changes in the fibula seen on axial ct images . contrary to this , the focal hepatic lesion in caudate lobe of liver showed significant increase in size and metabolic activity [ figure 1b - arrow head ] ; measuring 31 mm , with max suv of 14.6 on axial fused pet / ct images [ figure 1d - arrow ] . this prompted a histological correlation and fine - needle aspiration ( fna ) was done from the liver lesion . microscopic examination showed collection of epitheloid cells on papanicolaou stain [ figure 2a - arrows and figure 2b ] with pale oval shaped cells showing slipper shaped nuclei [ figure 2b - inset ] . mip image showing focal intense tracer uptake at the primary site in right tibia ( a - arrow ) with another focus of fdg uptake in liver ( a - arrowhead ) , which was confirmed on axial fused pet / ct image ( b - arrow ) . post chemotherapy mip image shows complete regression of fdg uptake in right tibia ( c - arrow ) ; however , there is increase in size and metabolic activity of fdg uptake in liver ( d - arrow , compared with b ) photomicrographs ( a : 100 , papanicolaou stain ) show epithelioid cells ( a - arrow ) , with pale elongated oval shaped cells ( b - 200 , papanicolaou stain ) showing slipper or sole of the foot shaped nuclei ( b - inset ) hepatic tuberculosis is rare and constitutes 1% of all cases of tuberculosis . in 70% patients , on morphologic imaging , it commonly appears as miliary tubercles , abscesses or as cholangitis . very rarely , multiple tuberculomas are seen ; however , there is no report which shows solitary focal hepatic tuberculosis . on fdg pet , there is intense tracer uptake in tuberculous lesions due to glut receptor expression on lymphocytes . this forms the basis of multiple reports of tuberculosis mimicking malignancy on fdg pet ; majority of these in cases with fdg avid disseminated nodal disease , few with skeletal lesions , but none demonstrating focal solitary lesions . report of hepatosplenic tuberculosis shows diffuse  hot  liver on fdg pet / ct . only a single report , similar to our case , shows hepatic tuberculosis in the setting of malignancy , seen as focal fdg uptake on pet / ct ; but , the patient had past history of disseminated tuberculosis , unlike our case where there was no past history or stigmata on examination to suggest old tuberculosis . considering the fact that liver is not the most common of metastatic sites for ewing 's family of tumors , an upfront histological confirmation should ideally be obtained if the imaging findings suggest an unusual pattern of disease spread . however , the focal nature of uptake and the intensity of metabolic activity , depicted by max suv , which was identical for the primary site and metastatic lesion , tilted the odds more in favor of metastases . there were other factors which also were considered , like the focality of lesion which also favors metastatic disease . delbeke et al . , have shown that a focal pattern of fdg uptake in liver favors a metastatic etiology over infection . furthermore , the fact that such a lesion was seen in the setting of ewing 's sarcoma which also demonstrates high grade fdg avidity , ruled it more in favor of metastases on baseline imaging . hence , an isolated focal hepatic fdg avid lesion , in a clinically unremarkable scenario like ours , is bound to pose a diagnostic dilemma . post chemotherapy scan showed complete regression of primary lesion ; however , the focal liver lesion showed metabolic and morphological progression . treatment failure at the metastatic site with good response at primary site , indicated that the liver lesion was non - metastatic which was proven on fna . thus , focal solitary liver lesion in an oncological setting , though fdg avid , should not be assumed to be metastatic particularly in tumors such as ewing 's sarcoma which do not have a high propensity for hepatic metastases at presentation . clinically , occult focal tuberculosis of liver , which also shows similar uptake pattern on fdg pet , though rare , should be kept at the back of the mind and a tissue diagnosis should be asked for before starting treatment .