Calcitonin levels in autoimmune atrophic gastritis-related hypergastrinemia.

PURPOSE: Calcitonin (Ct) is currently the most sensitive biochemical marker of C-cell disease (medullary thyroid cancer [MTC] and C-cell hyperplasia), but its specificity is relatively low. Our aim was to examine whether autoimmune atrophic gastritis (AAG) and chronic hypergastrinemia, with or without chronic autoimmune thyroiditis (AT), are conditions associated with increased Ct levels. METHODS: Three groups of patients were consecutively enrolled in this  multicentric study: group A consisted of patients with histologically-proven AAG (n = 13; 2 males, 11 females); group B fulfilled the criteria for group A but also had AT (n = 92; 15 males, 77 females); and group C included patients with AT and without AAG (n = 37; 6 males, 31 females). RESULTS: Median Ct levels did not differ between the three groups. Ct levels were undetectable in: 8/13 cases (61.5%) in group A, 70/92 (76.1%) in group B, and 27/37 (73.0%) in group C. They were detectable but ≤ 10 ng/L in 4/13 (30.8%), 20/92 (21.7%) and 7/37 (18.9%) cases, respectively; and they were > 10 ng/L in 1/13 (7.7%), 2/92 (2.2%) and 3/37 (8.1%) cases, respectively (P = 0.5). Only three patients had high Ct levels (> 10 ng/L) and high gastrin levels and had an MTC. There was no correlation between Ct and gastrin levels (P = 0.353, r = 0.0785). CONCLUSIONS: High gastrin levels in patients with AAG do not explain any hypercalcitoninemia, regardless of whether patients have AT or not. This makes it mandatory to complete the diagnostic process to rule out MTC in patients with high Ct levels and AAG.

Papillary thyroid carcinoma (PTC) in Lynch syndrome: Report of two cases and discussion on Lynch syndrome behaviour and genetics.

We present here two cases of papillary thyroid carcinoma (PTC) in patients affected by Lynch syndrome (LS). The first case is a 47-year-old woman with typical hereditary non-polyposis colorectal cancer (HNPCC) syndrome, reported with endometrial and ovarian carcinoma at age 43, and colon cancer at age 45. The patient underwent total thyroidectomy and central node dissection in 2007, at 47years old, with a histological diagnosis of PTC (T1aN1a). Molecular genetics showed a germ-line mutation of the MLH1 gene, 1858 G>T(E620X), with substitution of glycine with a stop codon at position 620. This mutation has pathogenetic significance and was considered responsible for the various tumours of the HNPCC spectrum. In particular, in the same kindred, spanning 5 generations, there were 5 members with colorectal cancer, 4 with endometrial cancer, 3 with gastric and 2 with breast cancer. The second case is a 34-year-old man with typical HNPCC syndrome with colonic resection for colon cancer at age 21. The patient underwent total thyroidectomy with central and lateral node dissection in 2010, at age 34, with a histological diagnosis of PTC with nodal metastases (pT4N1b). Molecular genetic analysis showed a germ-line mutation of the MSH2 gene (thymine insertion at position 907). This mutation had pathogenetic significance and was considered responsible for HNPCC development. Two similar cases have been reported: a 39-year-old woman, and a 44-year-old woman, affected by HNPCC syndrome, with anaplastic thyroid carcinoma and undifferentiated thyroid carcinoma, respectively. We reviewed the Lynch syndrome literature on the history, genetics and expanding tumour spectrum of this condition.