F(18) -2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) has become a well established tool in staging and assessing therapy response in lymphoma. Incidental thyroid uptake on PET is not uncommon and can pose a diagnostic and management challenge. We retrospectively evaluate the prevalence and clinical significance of incidental FDG uptake in the thyroid gland in patients with lymphoma. 1868 lymphoma patients underwent PET and PET-CT between August 2002 and August 2008. 52 patients (2.8%) demonstrated FDG thyroid uptake (M  =  17, F =  35; mean age 63 yr). Thyroid uptake was determined as focal or diffuse, maximum standardized uptake values (SUVmax) recorded as well as SUV max ratio compared to background mediastinum activity (SUVR). Corresponding CT findings on PET-CT were evaluated independently. Results were correlated with clinical, histopathological and imaging follow-up. 30 (1.6%) patients had focal thyroid uptake. 16 (53%) had histological confirmation either by surgery (n  =  7) or FNA under USS (n  =  9). The final diagnosis was benign in 12/30 patients and malignant in 9/30. The malignancy risk for focal thyroid uptake was 30%. Five patients had intercurrent thyroid cancer (four papillary, one microinvasive follicular) and four had lymphomatous involvement. There was no significant difference between the mean sizes of benign (23.7 mm, range 12-34) and malignant nodules (23.6 mm, range 8-48). The mean SUVmax of malignant and benign nodules was 4.4 (range 1.8-10.1) and 3.2 (range 1.8-6.9) respectively with no statistically significant difference. 22 (1.2%) patients had diffuse FDG uptake in thyroid and benign aetiology was found in all with adequate follow-up (15/22). Focal FDG thyroid uptake on PET or PET-CT in lymphoma patients warrants further investigations. The malignancy risk is 30% either due to intercurrent thyroid cancer or lymphomatous involvement. SUVmax, SUVR and CT attenuation characteristics are not helpful in distinguishing between benign and malignant aetiologies. Diffuse thyroid uptake has a benign aetiology.

Focal FDG uptake in the thyroid gland on PET/CT showed a malignancy risk of 32%. The intensity of uptake does not predict histology and underpins the importance of further investigations to exclude intercurrent thyroid cancer in suitable patients.

This review article focuses on the dermatologic manifestations of selected nutrient deficiencies, including protein-energy and micronutrient-related malnutrition. The various nutrient deficiencies presented may share common features. However, distinctive cutaneous signs may prompt clinicians to consider a nutritional cause and help distinguish a nutrient deficiency from other common dermatologic conditions. The recent reemergence of forgotten nutritional deficiencies, such as scurvy and pellagra, in the context of predisposing risk factors that may uniquely affect women more than men makes this topic timely. Recognition of nutritional disorders is important because appropriate treatment may reverse cutaneous signs and prevent irreversible sequelae.

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