No abstract

Background To evaluate FCH‐PET/CT and parathyroid 4D‐CT so as to guide surgery in patients with primary hyperparathyroidism (pHPT) and prior neck surgery. Methods Medical records of all patients referred for a FCH‐PET/CT in our institution were systematically reviewed. Only patients with pHPT, a history of neck surgery (for pHPT or another reason) and an indication of reoperation were included. All patients had parathyroid ultrasound (US) and Tc‐99m‐sestaMIBI scintigraphy, and furthermore, some patients had 4D‐CT. Gold standard was defined by pathological findings and/or US‐guided fine‐needle aspiration with PTH level measurement in the washing liquid. Results Twenty‐nine patients were included in this retrospective study. FCH‐PET/CT identified 34 abnormal foci including 19 ectopic localizations. 4D‐CT, performed in 20 patients, detected 11 abnormal glands at first reading and 6 more under FCH‐PET/CT guidance. US and Tc‐99m‐sestaMIBI found concordant foci in 8/29 patients. Gold standard was obtained for 32 abnormal FCH‐PET/CT foci in 27 patients. On a per‐lesion analysis, sensitivity, specificity, positive and negative predictive values were, respectively, 96%, 13%, 77% and 50% for FCH‐PET/CT, 75%, 40%, 80% and 33% for 4D‐CT. On a per‐patient analysis, sensitivity was 85% for FCH‐PET/CT and 63% for 4D‐CT. FCH‐PET/CT results made it possible to successfully remove an abnormal gland in 21 patients, including 12 with a negative or discordant US/Tc‐99m‐sestaMIBI scintigraphy result, with a global cure rate of 73%. Conclusion FCH‐PET/CT is a promising tool in the challenging population of reoperative patients with pHPT. Parathyroid 4D‐CT appears as a confirmatory imaging modality.

We propose the denomination 'T-cell papulosis associated with B-cell malignancy' (TCP-BCM) for this distinctive eruption. Although resulting in various histopathological pictures, it can be easily recognized by clinicians and may be identified by informed pathologists relying on some key features. An extravasation of tumour B cells with skin-homing properties associated with a secondary, predominant, T-cell immune reaction could explain the clinicopathologic aspect and the prolonged regressive and recurrent course of the disease.