Hyalinizing trabecular tumors (HIT) are very rare thyroid tumors whose diagnosis is difficult, particularly in cytology. They are frequently diagnosed as papillary carcinomas due to the cytological similarities between those two tumors (anisocariosis, intranuclear cytoplasmic inclusions, nuclear grooves and nuclear overlapping). Here, we report two HIT cases which were initially diagnosed as papillary carcinoma, on the preoperative cytology and for which the patients underwent total thyroidectomy with lymph node dissection. From these two cases and a literature review, we have searched for diagnostic criteria which could increase the sensitivity of HIT diagnosis in thin layer cytology. We have found that only the identification of the fibrillar and hyaline material within the cellular cluster of the HIT seems discriminating between both tumors, even though it is difficult to diagnose it is difficult to diagnose on thin layer cytology. One major help for the diagnosis would be the typical membranous and cytoplasmic MIB-1 immunostaining. However, no experiment has been undertaken with thin layer smears for HTT. (C) 2011 Elsevier Masson SAS. All rights reserved.

Objective: The objective of this study is to investigate whether preoperative ultrasound guided insertion of a hook-needle is useful in reoperations for cervical recurrent lymph node metastases of papillary thyroid cancer.Patients and methods: 8 patients with operated papillary thyroid cancer were included in this study. They all had suspicious nonpalpable cervical lymph nodes discovered during follow-up. These lymph nodes were identified by ultrasound imaging and their metastatic nature was confirmed by fine needle aspiration cytology and measurement of in situ thyroglobulin. In all cases, surgical excision of these lymph nodes was decided. All 8 patients had a hook-needle inserted in the suspicious lymph node(s) preoperatively and under ultrasound guidance.Results and conclusion: In all 8 patients, the suspicious lymph nodes were removed and their metastatic nature was confirmed by the final pathological examination. This localization technique is very helpful for the surgeon during the excision of small and nonpalpable lymph nodes, especially in previously operated area. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

II Gauge directional large core vacuum assisted biopsy has been used recently in the etiological diagnosis of microcalcifications. The objective of our work was to summarize the histological modifications resulting from vacuum biopsies observed on 31 surgical specimens issuing from a series of 109 biopsies performed over a 15-month period for malignant and borderline lesions. Histological modifications attributable to vacuum biopsies, scar tissue and displacements, were searched for in all cases. Scar tissue was seen as granulations, inflammation and hemorrhagic tissue associated or not with fat necrosis and/or foreign body giant-cell reaction. Displacements were seen as movements of injured tissue generally in the vicinity of scar tissue or vascular channels. Scar tissue was identified in all cases, presenting as star-shaped tissue measuring 12.8 mm on the average. Five displacements of either benign or malignant epithelia or of lymphovascular channels were observed (16% of the specimens). Scar tissue seen on surgical specimens indicates the location of the mammotome cut and confirms correctly directed surgery. It is particularly important to identify scar tissue because the lesions are nonpalpable and difficult to localize, or may have been totally removed at the initial biopsy. Displacements can be mistaken for infiltrating carcinoma or lymphatic invasion and must be carefully localized. They seem to be less frequent after vacuum biopsy.