Identification of Glandular (Acinar)/Tubule Formation in Invasive Carcinoma of the Breast: A Study to Determine Concordance Using the World Health Organization Definition

CONTEXT.—

The Nottingham Grading System (NGS) developed by Elston and Ellis is used to grade invasive breast cancer (IBC). Glandular (acinar)/tubule formation is a component of NGS.

OBJECTIVE.—

To investigate the ability of pathologists to identify individual structures that should be classified as glandular (acinar)/tubule formation.

DESIGN.—

A total of 58 hematoxylin-eosin photographic images of IBC with 1 structure circled were classified as tubules (41 cases) or nontubules (17 cases) by Professor Ellis. Images were sent as a PowerPoint (Microsoft) file to breast pathologists, who were provided with the World Health Organization definition of a tubule and asked to determine if a circled structure represented a tubule.

RESULTS.—

Among 35 pathologists, the κ statistic for assessing agreement in evaluating the 58 images was 0.324 (95% CI, 0.314-0.335). The median concordance rate between a participating pathologist and Professor Ellis was 94.1% for evaluating 17 nontubule cases and 53.7% for 41 tubule cases. A total of 41% of the tubule cases were classified correctly by less than 50% of pathologists. Structures classified as tubules by Professor Ellis but often not recognized as tubules by pathologists included glands with complex architecture, mucinous carcinoma, and the "inverted tubule" pattern of micropapillary carcinoma. A total of 80% of participants reported that they did not have clarity on what represented a tubule.

CONCLUSIONS.—

We identified structures that should be included as tubules but that were not readily identified by pathologists. Greater concordance for identification of tubules might be obtained by providing more detailed images and descriptions of the types of structures included as tubules.

The Effect of Topical Tacrolimus on Pedicled Flap Survival: A Histological Analysis

PURPOSE

Our previous rodent study demonstrated significantly decreased full-thickness necrosis in pedicled dorsal skin flaps with topical tacrolimus as compared with petroleum jelly. The pathophysiology of tissue necrosis involves lymphatic congestion, followed by venous congestion and ultimately arterial insufficiency. Topical tacrolimus has been shown to increase growth of lymphatic collateral vessels and decrease lymphedema, potentially obviating one contributor to necrosis. The purpose of this study was to investigate the vascular and histological differences between these 2 groups to identify the etiology of our research findings.

METHODS

A 3 × 10-cm cranially based dorsal skin flap was raised and reinset on 22 Sprague Dawley rats. They were randomized to receive 0.2 g of either topical petroleum jelly or topical 0.1% tacrolimus ointment daily to the flaps. The rats were killed 7 days postoperatively. Two blinded reviewers marked the total flap area as well as areas of viable tissue, reversible ischemia, and necrotic tissue. Full-thickness biopsies of each area were taken from 2 randomly chosen animals in each group. Paraffin-embedded tissue was sectioned to generate hematoxylin and eosin-stained slides. Representative images of each area of the flap were taken less than 40× magnification using light microscopy. Arteries, veins, and lymphatics in the dermal layer were quantified under blinded conditions by a trained pathologist and calculated per cross-sectional area using Fiji software.

RESULTS

The average area of the dorsal flaps in the control and tacrolimus groups was 22.5 and 23.9 cm2, respectively. Total necrotic area was significantly lower in rats receiving topical tacrolimus as compared with controls (P = 0.015). In the control cohort, average total number of vessels was 12.5, 6, and 0, in the areas of viable tissue, reversible ischemia, and necrosis, respectively. In the tacrolimus cohort, average total number of vessels increased was 20, 11.5, and 5.4, in the areas of viable tissue, reversible ischemia, and necrosis, respectively.

CONCLUSIONS

On a histological level, topical tacrolimus is correlated with increased vascular growth in areas most susceptible for ischemic damage as compared with topical control. Future work is needed to investigate vascular biomarkers and increase the power of our study.

Primary meningococcal pericarditis

We have described two patients with primary meningococcal pericarditis. The first patient required open surgical drainage. In the second patient, pericardiectomy was eventually required. Thirteen cases of primary meningococcal pericarditis have now been reported. All the patients survived, in contrast to purulent pericarditis of other causes.