Esophageal epidermoid metaplasia (EEM) is a rare condition that has not been described in Stevens-Johnson syndrome (SJS) and has only been described once in pediatrics. Neither the relationship, treatment, nor surveillance between SJS, esophageal strictures, and EEM has been established. We report the first case of EEM in an 8-year-old girl with esophageal stricture after SJS. Pediatric patients presenting with dysphagia after SJS should be evaluated for esophageal stricture and subsequent EEM development. Owing to EEMs, association with esophageal squamous cell cancer, close follow-up, biopsy surveillance for dysplasia, endoscopic treatment, and TP53 genetic sequencing should be considered.

Fibrous papules present clinically as benign, asymptomatic, dome-shaped, flesh colored papules on the face. Histologically, fibrous papules are characterized by fibrous stroma with fibroblasts and dilated blood vessels. Multiple variants of fibrous papules have been reported. Although scattered multinucleated cells in fibrous papules have been well described, we report a fibrous papule with abundant multinucleated ganglion-like giant cells that were immunoreactive with CD34. Recognition of such fibrous papule variants is important to avoid misdiagnosis as potentially more worrisome and/or aggressive melanocytic, soft tissue, or neural lesions that may require more aggressive treatment. Indeed, fibrous papules do not commonly appear on the differential diagnosis for lesions with multinucleated giant cells or ganglion-like cells and consideration should be given to their inclusion in the appropriate clinical setting.

Intraosseous schwannomas are rare benign tumors that most often occur at the mandible or sacrum. We present an unusual case of a bilobed schwannoma of the distal humerus with both intraosseous and extraosseous components. The extraosseous component was non-enhancing on initial MRI and enhanced on a subsequent MRI obtained after biopsy. We hypothesize that this change was attributable to decreased intra-tumoral pressure secondary to biopsy-related disruption of the tumor capsule.

Context.—

Digital pathology using whole slide images has been recently approved for primary diagnosis in clinical surgical pathology practices. Here we describe a novel imaging method, fluorescence-imitating brightfield imaging, that can capture the surface of fresh tissue without requiring prior fixation, paraffin embedding, tissue sectioning, or staining.

Objective.—

To compare the ability of pathologists to evaluate direct-to-digital images with standard pathology preparations.

Design.—

One hundred surgical pathology samples were obtained. Samples were first digitally imaged, then processed for standard histologic examination on 4-μm hematoxylin-eosin-stained sections and digitally scanned. The resulting digital images from both digital and standard scan sets were viewed by each of 4 reading pathologists. The data set consisted of 100 reference diagnoses and 800 study pathologist reads. Each study read was compared to the reference diagnosis, and also compared to that reader's diagnosis across both modalities.

Results.—

The overall agreement rate, across 800 reads, was 97.9%. This consisted of 400 digital reads at 97.0% versus reference and 400 standard reads versus reference at 98.8%. Minor discordances (defined as alternative diagnoses without clinical treatment or outcome implications) were 6.1% overall, 7.2% for digital, and 5.0% for standard.

Conclusions.—

Pathologists can provide accurate diagnoses from fluorescence-imitating brightfield imaging slide-free images. Concordance and discordance rates are similar to published rates for comparisons of whole slide imaging to standard light microscopy of glass slides for primary diagnosis. It may be possible, therefore, to develop a slide-free, nondestructive approach for primary pathology diagnosis.

Neuroendocrine tumors (NETs) arising from tailgut cysts are a rare but increasingly reported entity with gene expression profiles that may be indicative of the gastrointestinal cell of origin. We present a case report describing the unique pathological and genomic characteristics of a tailgut cyst NET that metastasized to liver. The histologic and immunohistochemical findings were consistent with a well-differentiated NET. Genomic testing indicates a germline frameshift in BRCA1 and a few somatic mutations of unknown significance. Transcriptomic analysis suggests an enteroendocrine L cell in the tailgut as a putative cell of origin. Genomic profiling of a rare NET and metastasis provides insight into its origin, development, and potential therapeutic options.

Serous cystadenocarcinoma (SCAC) of the pancreas is rare, with only 35 cases reported in the literature. We present a case of SCAC, comparing the clinical presentation, management and molecular features of this case to a series of serous cystadenoma (SCA), which may be a precursor. Compared with SCAs (n = 5), SCAC was larger (11.5 vs median 3.6 cm). The case of SCAC invaded the spleen and exhibited distant metastasis, a requirement for diagnosis since pathologic features are otherwise indistinguishable from SCA. VHL mutations have been reported in about half of SCA in the literature. Accordingly, we identified either somatic or germline VHL mutations in 3 of 5 SCAs (60%), yet no pathogenic mutation was identified in the SCAC. A somatic mutation in IDH1 was found in SCAC only. This has been associated with multiple malignancies, is targetable with the drug ivosidenib and should be studied as a progression factor in SCAC.