Endocrine Abstracts

Rothmund-Thomson syndrome (RTS) usually presents with physical stigmata (poikiloderma, ectodermal dysplasia, juvenile cataracts…) and it´s associated with malignancies in patients with homozygous or compound heterozygous mutations in the RECQL4 helicase gene (RTS-II). Neoplasms include osteosarcoma in childhood and skin cancer later in life, with occasional malignancies affecting other tissues (leukemia, lymphoma and gastrointestinal adenocarcinomas). To our best knowledge, its association with neuroendocrine tumors has not been reported. We present one patient with this association. A 33-year-old woman was admitted in February 2020 for diarrhoea (4–5 stools/day) with urgency and mucus. At six she had been diagnosed with RTS-II after detecting osteosarcoma of the right femur, treated with amputation and chemotherapy with no evidence of disease in check-ups. In 2015, an ultrasound showed two liver lesions in segment VI and biopsy of the larger one was reported as a benign hepatocyte proliferation. In 2018, a cutaneous squamous cell carcinoma on the left heel had been resected and a CT scan showed a tumor in the duodenal setting, with two endoscopic US-guided FNAC obtaining insufficient cytological material for diagnosis. Colonoscopy disclosed a 1.8 cm tubule-villous adenoma with high-grade dysplasia and gastroscopy showed a tumor located posterior to the duodenal bulb, about 15 mm in diameter. Endoscopic biopsy showed a well-differentiated NET (G2). Biochemistry revealed dissociated cholestasis and elevation of chromogranin A (3, 001ng/ml; NV<100) with slightly elevated glucagon (153 pg/ml; NV<100). SPECT-CT with Tektrotyd confirmed the uptake of the lesion, as well as of adjacent adenopathies, without hepatic involvement. Operated on May 2020, a hard lesion on the posterior aspect of the duodenal bulb and adjacent adenopathies were resected. Intraoperative ultrasound showed more than 10 liver lesions in both lobes, whose biopsy confirmed their metastatic nature. Pathology diagnosed a well-differentiated NET of 2 cm, infiltrating up to muscularis propria, with lymphatic invasion and lymph nodes affected. Ki-67:15%. Genetic study discovered two variants of the RECQL gene in compound heterozygosis: c.1620+1G>C (NM_004260.3) and c.2547_2548delGT (NM-004260.3). After surgery, two sessions of transarterial chemoembolization with adriamycin were performed. Seven months later, a SPECT-CT with Tektrotyd shows uptake in non-treated hepatic segments and regional periduodenal adenopathies. CgA levels have reduced to 923 ng/ml. In conclusion, this is the first reported case of NET in a patient with RTS. Duodenal malignancy was previously reported in association with RTS-II. Increased awareness of the risk of gastrointestinal malignancy in patients with RTS could improve detection and outcomes in these patients.