A routine review was requested for the cytology specimen of a 26-year-old female patient. The specimen was obtained from a right thyroid nodule, processed as liquidbased preparation using ThinPrep technology (Hologic, Inc., Marlborough, MA) and Papanicolaou-stained. Review of the slide showed a cellular sample with variably sized clusters and single dispersed cells. The clusters were of rounded and papillary configuration and focally showed fibrovascular cores (Fig. 1). Dense material of round to elongated shape with knobby outlines was present at the center of some clusters (Fig. 2). The epithelial cells at the surface of the clusters were crowded and showed prominently vacuolated cytoplasm with sharp borders. Centrifugal positioning of the nuclei away from the center of the cluster was a conspicuous feature (Fig. 3). The nuclei showed irregular membranes with folds and grooves, dispersed chromatin, and tiny nucleoli. Intranuclear cytoplasmic pseudoinclusions or mitotic activity were not noticeable. Scattered foamy histiocytes were present in the background. Colloid, either thin or thick, was not identified. Material for ancillary studies was not available.The specimen was reported as suspicious for papillary thyroid carcinoma (PTC) by the original laboratory. The possibility of a PTC variant with hobnail morphology was raised upon review. The patient underwent total thyroidectomy 3 weeks later. An intraoperative consultation for an excised left paratracheal lymph node showed a small focus of bland follicular epithelium reported as suspicious for metastatic PTC. The surgical specimen of 18.7 g showed an encapsulated nodule (2.1 cm 3 1.7 cm 3 1.5 cm). The tumor displayed classical architecture with predominant papillary and focal micropapillary structures, 60% hobnail cytomorphology and very focal (<10%) tall cell features. The diagnosis of invasive hobnail cell variant PTC (HPTC) was rendered (Fig. 4). An incidental follicular variant papillary microcarcinoma was detected in the left lobe. The background thyroid parenchyma showed follicular nodular disease (adenomatoid nodules) and chronic lymphocytic thyroiditis. Three of five concurrently resected lymph nodes were positive for metastatic PTC.A series of eight cases of PTC with hobnail features was described by Asioli et al. in 2010. 1 Hobnail morphology in PTC had been noticed prior to this by other researchers.2-6 Morphologic criteria for inclusion in the 2010 case series were (1) nonsolid type of PTC, (2) 10% tall/columnar or diffuse sclerosing features, and (3) loss of polarity/cohesiveness with hobnail features in 30% of tumor cells.1 Based on these criteria, the prevalence of PTC with prominent hobnail features was estimated as 0.236% of all PTC at the author's institution. The cases described presented at an advanced age (mean 57.6 years, range 28-78) compared to classic PTC and more common variants (tall cell, columnar cell, diffuse sclerosing), showed an aggressive behavior with propensity for lymph node and distant metastases, and poor prognosis with...

The aim of this study was to find the most suitable manual measurements to estimate the age of preserved fetuses. A new technique was used to make successful ultrasonic measurements on 86 out of 100 preserved fetuses under conditions simulating the intrauterine environment. The ultrasonographic images of the preserved specimens were very similar to those of live fetuses. Ultrasonic measurements of standard parameters, and the ages derived from them, were computed directly by the ultrasound scanning machine. Manual measurements were made of the same parameters using established techniques and standard tables for estimating fetal age. The measurements and the ages obtained for each parameter by the two techniques were statistically compared using the limits of agreement (Bland and Altman, 1986). Of the manual measurements used in the estimation of fetal age, foot length was found to be the most suitable parameter for practical use. Biparietal diameter was equally good, but the head circumference was the most precise, especially when used in conjunction with the formulae developed for ultrasonic measurements. Crown‐rump length was found to be unsuitable to age fetuses beyond the first trimester due to distortion of the spine caused by compression in storage. Clin. Anat. 12:84–93, 1999. © 1999 Wiley‐Liss, Inc.

The aim of this study was to find the most suitable manual measurements to estimate the age of preserved fetuses. A new technique was used to make successful ultrasonic measurements on 86 out of 100 preserved fetuses under conditions simulating the intrauterine environment. The ultrasonographic images of the preserved specimens were very similar to those of live fetuses. Ultrasonic measurements of standard parameters, and the ages derived from them, were computed directly by the ultrasound scanning machine. Manual measurements were made of the same parameters using established techniques and standard tables for estimating fetal age. The measurements and the ages obtained for each parameter by the two techniques were statistically compared using the limits of agreement (Bland and Altman, 1986). Of the manual measurements used in the estimation of fetal age, foot length was found to be the most suitable parameter for practical use. Biparietal diameter was equally good, but the head circumference was the most precise, especially when used in conjunction with the formulae developed for ultrasonic measurements. Crown-rump length was found to be unsuitable to age fetuses beyond the first trimester due to distortion of the spine caused by compression in storage.