CASE REPORT 68 Ga-DOTATATE uptake in pineal gland, a rare physiological variant: case series Saima Riaz 1 • Rizwan Syed 1 • Evangelia Skoura 1 • Alshaima Alshammari 1 • Mark Gaze 2 • Rakesh Sajjan 1 • Richard Halsey 1 • Jamshed Bomanji 1 Received: 9 March 2015 / Accepted: 3 July 2015 Ó The Japanese Society of Nuclear Medicine 2015 Abstract 68 Ga-DOTATATE PET–CT is widely used for the evaluation of neuroendocrine tumours. Knowledge of the physiological distribution of the radiotracer is of critical importance in characterizing focal areas of uptake. In this case series, we report three paediatric cases (average age 4.7 years ± 0.6 SD) with diagnosed advanced stage IV Neuroblastoma. Two had 68 Ga-DOTATATE PET–CT scans and one underwent 68 Ga-DOTATATE PET–MRI scan to assess for suitability of molecular therapy. Focal increased tracer uptake in the pineal gland was noted in all cases with no morphological abnormality on the corre- sponding CT and MRI scans. The uptake within the gland was thought to be a physiological variant rather than metastases owing to the heterogeneity of somatostatin receptors expression. The pineal gland has been reported to express somatostatin receptors. The physiological distri- bution of 68 Ga-DOTATATE uptake in the pineal gland is not routinely seen. Furthermore, the possibility of pineal meningioma is very unlikely as pineal meningiomas are very rare and there was no convincing morphological evidence of meningiomas on CT/MRI scan. Keywords Somatostatin receptor Á 68 Ga-DOTATATE Á PET–CT scan Á PET–MRI scan Á Pineal gland Introduction 68 Ga-DOTATATE is a somatostatin analogue with high affinity for somatostatin receptor subtype 2 (SST2). 68 Ga- DOTATATE is used for PET imaging of neuroendocrine tumours with over-expression of somatostatin receptors [1]. The recognised physiological bio-distribution of 68 Ga- DOTATATE is to pituitary, salivary glands, thyroid, gastric lining, liver, spleen, adrenal glands, pancreas and the pros- tate. All these organs express SST2 receptors. Urinary and bowel activities are the excretory routes for the tracer [2]. In the head and neck region, somatostatin receptors have been reported in the cerebral cortex and subcortical structures including the limbic system and basal nuclei [3]. However, the hydrophilic 68 Ga-DOTATATE does not cross the blood– brain barrier and shows no brain uptake. Occasionally small foci of increased activity are seen over the cerebral convexities or at the base of skull, which are usually indicative of meningiomas, in the absence of clinical symptoms [2]. The pineal gland is a part of the epithalamus and expresses somatostatin receptors. This small endocrine gland produces melatonin and maintains the circadian rhythm [4]. In this case series, we describe 3 patients with stage IV Neuroblastoma with unusual 68 Ga-DOTATATE uptake in the pineal gland and no corresponding morphological abnormality on CT and MRI scans. Informed consent was attained prior to the PET/CT or PET/MRI imaging in all three cases. Case 1 A 5-year-old female patient was diagnosed with stage IV Neuroblastoma. Baseline 123 I-MIBG scan showed right suprarenal primary tumour and widespread skeletal & Saima Riaz saimarz.dr@gmail.com 1 Institute of Nuclear Medicine, University College Hospitals NHS Trust, 235 Euston Road, London NW1 2BU, UK 2 Department of Paediatric and Adolescent Oncology, University College London Hospitals NHS Foundation Trust, London, UK 123 Ann Nucl Med DOI 10.1007/s12149-015-1000-8