Gender-specific correlation of intranodular chronic lymphocytic thyroiditis with thyroid nodule size, echogenicity, and histologically-verified cytological class of malignancy risk

No data are available on the cytologically and histologically demonstrated presence of intranodular chronic lymphocytic thyroiditis (ICLT) and on the ICLT relationship with thyroid nodule characteristics such as size, echotexture and nature (benign or malignant). We wished to fill this gap by analyzing data in a gender-specific fashion. We studied 408 thyroid nodules from 408 consecutive persons (325 females and 83 males). Nodules were isoechoic (n = 268) or hypoechoic (n = 140), ICLT +ve (n = 113 [27.7%]) or ICLT −ve (n = 295), cytologically low-risk (n = 197) or high-risk (n = 211), histologically benign (n = 263) or malignant (n = 145). ICLT prevailed in females (97/113) and in hypoechoic nodules (58/140 [41.4%] vs 55/268 [20.5%], P < 0.0001). Compared to males, females had (i) smaller nodules (18.5 ± 9.4 vs 23.3 ± 13.4 mm, P = 0.0002), a difference due to the isoechoic nodules (21.1 ± 9.8 vs 26.6 ± 14.1 mm, P = 0.0006), (ii) lower rates of high-risk nodules (161/325 [49.5%] vs 50/83 [60.2%], P = 0.082) and malignant nodules (110/325 [33.8%] vs 35/83 [42.2%] P = 0.16). ICLT +ve nodules were smaller than the ICLT −ve ones (15.4 ± 6.9 vs 20.9 ± 11.2 mm, P < 0.0001), a difference due to the isoechoic nodules (17.5 ± 6.5 vs 23.6 ± 11.7 mm, P = 0.0003). The smallest nodules were hypoechoic, cancerous and ICLT +ve nodules in males (9.5 ± 4.0 mm); the largest were isoechoic, cytologically risky and ICLT −ve in males (29.1 ± 13.2 mm). Compared to ICLT −ve nodules, malignancy prevailed in ICLT +ve nodules (55/113 [48.7%] vs 90/295 [30.5%], P = 0.0006), both in hypoechoic (37/58 [63.8%] vs 41/82 [50.0%]) and isoechoic nodules (18/55 [32.7%] vs 49/213 [23.0%]). ICLT +ve hypoechoic nodules of females and ICLT −ve hypoechoic nodules of males had the greatest rate of malignancy (67% both), while ICLT −ve isoechoic nodules of females had the lowest (19%). In conclusion, presence/absence of ICLT is associated with some sexually dimorphic characteristics of thyroid nodules. Adding the specification of ICLT positivity/negativity in cytological reports may help improving the risk of malignancy at least in some groups of thyroid nodules.