Currently, obesity is one of the leading causes death in the world. Shortly before 2000, researchers began describing metabolically active adipose tissue on cancer-surveillance ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in adult humans. This tissue generates heat through mitochondrial uncoupling and functions similar to classical brown and beige adipose tissue in mice. Despite extensive research, human brown/beige fat’s role in resistance to obesity in humans has not yet been fully delineated. FDG uptake is the de facto gold standard imaging technique when studying brown adipose tissue, although it has not been rigorously compared to other techniques. We, therefore, present a concise review of established and emerging methods to image brown adipose tissue activity in humans. Reviewed modalities include anatomic imaging with CT and magnetic resonance imaging (MRI); molecular imaging with FDG, fatty acids, and acetate; and emerging techniques. FDG-PET/CT is the most commonly used modality because of its widespread use in cancer imaging, but there are mechanistic reasons to believe other radiotracers may be more sensitive and accurate at detecting brown adipose tissue activity. Radiation-free modalities may help the longitudinal study of brown adipose tissue activity in the future.

Objective: To assess the association of adipocyte size with cellular lipolysis and between cellular lipolysis and whole‐body lipid oxidation. This study also assessed the association between adipocyte size and cellular lipolysis with weight and fat mass gain.Methods: Subjects had assessment of percent body fat (%fat) and adipose tissue biopsy forin vitrolipolysis (n =325), and a subset of subjects had measurement of whole‐body lipid oxidation (n =112). A subset of subjects (n =243) returned for repeated measurements of body weight and composition (mean follow‐up 8.2 ± 5.5 years).Results: In vitrolipolysis (r =0.47,P <0.0001) and adipocyte size (r =0.49,P <0.0001) were strongly associated with %fat.In vitrolipolysis (P =0.04) but not adipocyte size (P =0.44) was associated with whole‐body fat oxidation. Adipocyte size was not associated with rate of percent weight gain (P =0.20) but was negatively associated with rate of percent fat mass gain (P =0.01).In vitrolipolysis was negatively associated with rate of percent weight gain (P =0.02) and had a marginal negative association with rate of percent fat mass gain (P =0.08).Conclusions: These results indicate inherent characteristics of adipocytes, including size and lipolytic activity, may be important determinants of whole‐body lipid oxidation and subsequent weight gain.

Chordoma is a rare invasive bone tumor that may occur anywhere along the neuraxis. A total of three primary histological varieties have been identified: conventional, chondroid, and dedifferentiated. We report a case of an 8-year-old white girl who presented with conventional chordoma, was treated with surgical resection and mixed proton and photon beam therapy, and had a recurrence in the resection cavity 2.5 years later with dedifferentiated morphology. The recurrent tumor did not express brachyury, a recently identified protein specific to tissue of notochordal origin. The short time period between radiation therapy and dedifferentiation, low dose of photons, and rarity of dedifferentiated skull base chordomas in pediatric patients should alert clinicians to the possibility of chordoma dedifferentiation after proton beam therapy.

Parastomal gallbladder herniation is a rare complication of enterostomies with only 6 previously reported cases. Most cases have occurred in elderly women. Patients typically presented with acute abdominal pain and the majority was managed operatively. Here, we report the clinical course of an 88-year-old female who presented with signs of sepsis and minimal abdominal symptoms. She was subsequently found to have a parastomal gallbladder herniation and Klebsiella pneumoniae bacteremia. Given the patient's multiple comorbidities, she was managed nonoperatively with manual reduction of the parastomal hernia and antibiotics.