Free Silicone With Giant Cell Reaction Can Enhance on Breast MRI.

Background Breast augmentation with silicone implants is commonplace, and such implants have a risk of rupture which increases over time. Most implant ruptures are asymptomatic, and magnetic resonance imaging (MRI) is a recommended imaging modality for surveillance to detect these events. If a silicone leak enhances on MRI, it is currently categorized according to the Breast Imaging Reporting and Data System (BI-RADS) as category 4, which results in a recommendation for biopsy even when free silicone leakage is the most likely diagnosis. In this article, we present a case series that illustrates this issue with the BI-RADS system and propose an algorithmic approach that may allow some patients to be placed into BI-RADS category 3 and avoid biopsy. Methodology Eight cases of silicone breast implant rupture were identified at the University of Texas Medical Branch at Galveston over a five-year period. Two cases were excluded because MRI was not performed. The remaining six cases were evaluated for history and physical findings as well as mammogram, ultrasound, and MRI. All identified cases had been categorized as BI-RADS 4 and underwent biopsy. Results The six cases in this series exhibited pre-biopsy radiographic findings that were most consistent with silicone implant rupture. The ruptures were proven by biopsy, and no evidence of malignancy was identified in any of the patients. Conclusions Free silicone from breast implant rupture can present with enhancement on MRI. The two main categories of breast MRI enhancement, namely, mass and non-mass, include malignancies in their differential diagnoses and result in a BI-RADS category 4 designation. By correlating the findings with other imaging modalities, some of these patients can be classified as BI-RADS category 3 and biopsy can safely be avoided.

Intracystic Papillary Carcinoma: A Case Report.

Intracystic papillary carcinoma (IPC) of the breast is a rare form of in-situ carcinoma, which is contained within a dilated duct. Mammography and ultrasound may provide clues to its presence, but formal diagnosis always requires histologic evidence. Although IPC is associated with an excellent prognosis, surgical resection is important in order to rule out the possibility of any invasive component, which would result in the need for more aggressive treatment. In this paper, we review the radiographic and histologic features of this interesting diagnosis, present a patient case, and explore the possible reason why IPC does not require the same treatment modalities as the more common ductal carcinoma in situ (DCIS).

Elucidation of a lingual detection mechanism for high-viscosity solutions in humans.

While perception of high-viscosity solutions (η > 1000 cP) is speculated to be linked to filiform papillae deformation, this has not been demonstrated psychophysically. Presently, just-noticeable-viscosity-difference thresholds were determined using the forced-choice staircase method and high-viscosity solutions (η = 4798-12260 cP) with the hypotheses that the tongue would be chiefly responsible for viscosity perception in the oral cavity, and that individuals with more, longer, narrower filiform papillae would show a greater acuity for viscosity perception. Subjects (n = 59) evaluated solutions in a normal, "unblocked" condition as well as in a "palate blocked" condition which isolated the tongue so that only perceptual mechanisms on the lingual tissue were engaged. Optical profiling was used to characterize papillary length, diameter, and density in tongue biopsies of a subset (n = 45) of participants. Finally, psychophysical and anatomical data were used to generate a novel model of the tongue surface as porous media to predict papillary deformation as a strain-detector for viscosity perception. Results suggest that viscosity thresholds are governed by filiform papillae features. Indeed, anatomical characterization of filiform papillae suggests sensitivity to high-viscosity solutions is associated with filiform papillae length and density (r = 0.68, p < 0.00001), but not with diameter. Modelling indicated this is likely due to a reciprocal interaction between papillae diameter and fluid shear stress. Papillae with larger diameters would result in higher viscous shear stress due to a narrower gap and stronger fluid-structure interaction, but a larger-diameter papilla would also deform less easily.

Development of a "pure-tactile" assessment of edge discrimination in the hands and oral cavity.

Oral cavity edge perception acuity relative to the fingertip has previously been evaluated by the utilization of cognitively-loaded, stereognostic methods. However, with the lack of connection of the tongue to the visual association cortex, there is concern the superior acuity of the fingertip may be attributable to the cognitive component of the task. Here, perception acuity is evaluated by assessing participants' (n=29) just-noticeable-difference threshold for edge sharpness tiles using the finger and tongue. As expected, the pure-tactile task found greater acuity in the tongue, suggesting the cognitive component of the previous task confounded results and should not be used.

Comparative tactile sensitivity of the fingertip and apical tongue using complex and pure tactile tasks.

Both the tongue and fingertip are highly tactile tissues relevant in texture perception, but work comparing relative sensitivity to elucidate potential differences in stimulus processing is limited. Presently, the acuity of the tongue and fingertip were compared using a series of tactile acuity tasks. We hypothesized the tongue would show superior acuity regardless of stimuli due to an absent epidermal barrier and its involvement in many high-sensitivity behaviors (e.g. eating, speaking). Acuity was determined using three different tests, two "purely-tactile" just noticeable difference (JND) tasks (punctate pressure and roughness sensitivity) and a more-complex, stereognostic letter-recognition task to evaluate point-and-edge sensitivity. JNDs were determined using the forced-choice staircase method for the punctate deformation force of a monofilament (F;0.0044-0.010 g) and the surface roughness of stainless steel coupons (Ra; 0.177-0.465 µm) in populations of 30 and 31 individuals, respectively. Point-and-edge sensitivity was assessed by determining the letter recognition threshold (RT) based on height (h;1.5-8.0 mm) in an additional 28 individuals using a modified staircase method. While subjects had significantly lower JNDs with their tongues for both "purely-tactile" tasks (punctate: 0.0017 ±â€¯0.0001 g vs. 0.0023 ±â€¯0.0002 g (fingertip), p = .018; roughness: 0.039 ±â€¯0.004 µm vs. 0.112 ±â€¯0.020 µm (fingertip), p < .001), subjects had significantly higher RTs with their tongues for the letter identification task (3.98 ±â€¯0.84 mm vs. 4.54 ±â€¯1.41 mm (fingertip), p = .0417). The latter difference is likely attributable to the more complex nature of the RT task and the finger's frequent involvement in object recognition. Binomial statistics (p = 1/2, α = 0.05) showed a significant number of subjects were better at the roughness task with their tongues (p = .021); however, a significant majority were better at the letter identification task with their fingers (p = .049); no significant difference was found for the punctate pressure task. While data appear to suggest the tongue is more sensitive to exclusively tactile stimuli, further study of other "pure-tactile" sensations should help clarify the contradictory results of the RT task.