Giant Basal Cell Carcinoma of the Lateral Neck: A Case Study.

A giant basal cell carcinoma (GBCC) is a rare variant of basal cell carcinoma (BCC) that is larger (>5 cm) and more aggressive. While BCC is usually surgically excised as a small, local tumor, cases of GBCC represent a considerable portion of BCC malignancies and mortality. The growth of GBCC is hypothesized to be multifactorial, and due to the successful treatment of BCC, available data is limited. We present a case of GBCC found during routine post-mortem dissection in a 92-year-old male cadaver. The neoplasm showed predilection to periauricular soft tissue invasion, despite demonstrating high-risk characteristics for metastasis. Microscopic analysis demonstrated an infiltrative growth pattern and neurotropism. Perineural spread could be observed on gross dissection, indicating a worse prognosis, but there was no evidence of lymphatic or hematogenous spread. This is most likely due to the stromal dependence of BCC. Local invasion of the primary tumor likely compromised head and neck function, but there was no secondary tumor evidence. There were no histopathological findings that indicate an aggressive growth or metastatic transformation of the tumor. Therefore, while a conclusion about duration cannot be made due to the anonymity of the cadaver, duration of growth likely was a significant factor in mortality.

Deep oncopanel sequencing reveals within block position-dependent quality degradation in FFPE processed samples.

BACKGROUND: Clinical laboratories routinely use formalin-fixed paraffin-embedded (FFPE) tissue or cell block cytology samples in oncology panel sequencing to identify mutations that can predict patient response to targeted therapy. To understand the technical error due to FFPE processing, a robustly characterized diploid cell line was used to create FFPE samples with four different pre-tissue processing formalin fixation times. A total of 96 FFPE sections were then distributed to different laboratories for targeted sequencing analysis by four oncopanels, and variants resulting from technical error were identified. RESULTS: Tissue sections that fail more frequently show low cellularity, lower than recommended library preparation DNA input, or target sequencing depth. Importantly, sections from block surfaces are more likely to show FFPE-specific errors, akin to "edge effects" seen in histology, while the inner samples display no quality degradation related to fixation time. CONCLUSIONS: To assure reliable results, we recommend avoiding the block surface portion and restricting mutation detection to genomic regions of high confidence.

Primary Cutaneous B-Cell Lymphoma Complicated by Clonal T-Cell Populations: A Diagnostic Dilemma.

ABSTRACT: Cutaneous lymphomas, both B-cell and T-cell, are not uncommonly seen in the skin, but those lymphomas exhibiting clonality for both B-cell and T-cell populations are scarce. Characterization of dual receptor rearrangement as primary composite lymphoma versus primary lymphoma with reactionary response is complex and often a challenge that goes unrecognized. In this study, we report a unique case of T-cell gene rearrangement positivity complicating the diagnosis of primary cutaneous low-grade B-cell lymphoma along with a review of reported cases containing dual receptor rearrangement to identify trends among final diagnostic decisions. As one might guess, for cutaneous lymphomas presenting with clonality for both T-cell and B-cell receptors, diagnosis can be difficult and confusing because the differential is broad. The literature suggests the majority of these cases may be cutaneous composite lymphomas. However, immunohistochemical, clinical, and histomorphologic features must all be assessed for an accurate diagnosis, which is critical for proper prognosis and therapy.

Atypical Mycobacterial Infection Arising Amid Corticosteroid Therapy for Livedoid Vasculopathy.

Patients who suffer from rare skin diseases may try numerous therapies with many potential side effects before achieving remission. Livedoid vasculopathy (LV) is one such rare disease that lacks a definitive treatment as evidenced by randomized controlled trials. Although corticosteroids help reduce the pain flares associated with LV, they come at the risk of immunosuppression. We present a case of disseminated cutaneous infection of M. chelonae/abscessus arising in a diabetic patient on long-term corticosteroid therapy. This patient required an intensive antibiotic regimen and potentially lifelong antibiotic suppression pending improvement of her disseminated cutaneous infection. We report this case to increase awareness of the diagnostic consideration of atypical, rapidly growing mycobacterial (RGM) infection when encountering patients with a diffuse onset of ulcerative skin nodules amid a background of diabetes and long-term corticosteroid use.

Peritoneal Deciduoid Mesothelioma: An Unusual Presentation Complicating an Already Challenging Diagnosis.

This report highlights a diagnostically challenging case of diffuse deciduoid mesothelioma occurring in the peritoneum of a 25-year-old woman, 8 months postpartum. Optimally debulked tumor consisted of sheets of polygonal cells arranged in solid, trabecular, and pseudopapillary configurations, with vesicular, occasionally grooved nuclei and small nucleoli. A barrage of immunohistochemical stains revealed an unusual staining pattern characterized by diffusely positive keratin, WT-1, and mesothelin staining, but lack of calretinin positivity. Electron microscopy demonstrated only rare thin, long, branching cellular projections. Cytogenetics revealed balanced translocations of 12p and 1q and 16p. Based on compiled ancillary studies, a diagnosis of deciduoid mesolthelioma was made and supported by consultations from experts at 3 outside facilities. Twenty-seven months after diagnosis, the patient is alive and undergoing treatment with progression of disease. This case is presented in detail, and a discussion of the diagnostic criteria and current application of those criteria is provided.

Mucosal melanomas: Site-specific information, comparisons with cutaneous tumors, and differential diagnosis.

Melanoma of the skin is the fifth leading new cancer diagnosis, having accounted for almost 77,000 cases and more than 9000 deaths in the United States in 2013. Although cutaneous neoplasms of this type are relatively common, their mucosal counterparts are not. Mucosal melanomas comprise approximately 1.3% of all melanocytic malignancies. Although they are rare, these lesions present at an advanced stage with more adverse prognoses. In addition, at a molecular level, they have proven to be distinct entities because they possess genetic mutations not usually seen in their cutaneous counterparts. Conversely, a sizable proportion of mucosal melanomas lack the gene aberrations seen in cutaneous melanomas. Such findings indicate different pathways in tumorigenesis for the two subtypes. Because melanomas arising from the mucosae are not often encountered, very little has been published on staging guidelines and prognostic factors. This causes dilemmas for both patients and physicians. Further work is necessary to define staging systems for all mucosal locations, so that accurate prognoses can be assigned to such lesions.