Epithelioid Hemangioendothelioma with WWTR1-CAMTA1 Fusion in the Parotid Gland Presenting as Bell's Palsy.

Epithelioid hemangioendothelioma is a rare tumor of endothelial differentiation most commonly arising in soft tissue, liver, and lung, following a variable clinical course. Most cases are characterized by a t(1;3)(p36;q23-25) resulting in WWTR1-CAMTA1 fusion. Only five epithelioid hemangioendothelioma have been previously reported arising in the salivary glands. None have presented as Bell's palsy. In the current case, a 37-year-old female presented with a longstanding complaint of pain and fullness in the right preauricular region and progressive episodes of Bell's palsy and facial nerve weakness. Surgical resection showed a tumor comprised of atypical cells with occasional intracytoplasmic vacuoles in a fibromyxoid stroma. Immunohistochemical stains demonstrated the neoplastic cells expressed ERG, CD31, and CD34, confirming vascular differentiation. Fluorescence in situ hybridization revealed a t(1;3)(p36;q25), confirming a diagnosis of epithelioid hemangioendothelioma. At 12-month follow-up, the patient has no evidence of disease.

A Deep Learning Convolutional Neural Network Can Differentiate Between Helicobacter Pylori Gastritis and Autoimmune Gastritis With Results Comparable to Gastrointestinal Pathologists.

CONTEXT.­: Pathology studies using convolutional neural networks (CNNs) have focused on neoplasms, while studies in inflammatory pathology are rare. We previously demonstrated a CNN that differentiates reactive gastropathy, Helicobacter pylori gastritis (HPG), and normal gastric mucosa. OBJECTIVE.­: To determine whether a CNN can differentiate the following 2 gastric inflammatory patterns: autoimmune gastritis (AG) and HPG. DESIGN.­: Gold standard diagnoses were blindly established by 2 gastrointestinal (GI) pathologists. One hundred eighty-seven cases were scanned for analysis by HALO-AI. All levels and tissue fragments per slide were included for analysis. The cases were randomized, 112 (60%; 60 HPG, 52 AG) in the training set and 75 (40%; 40 HPG, 35 AG) in the test set. A HALO-AI correct area distribution (AD) cutoff of 50% or more was required to credit the CNN with the correct diagnosis. The test set was blindly reviewed by pathologists with different levels of GI pathology expertise as follows: 2 GI pathologists, 2 general surgical pathologists, and 2 residents. Each pathologist rendered their preferred diagnosis, HPG or AG. RESULTS.­: At the HALO-AI AD percentage cutoff of 50% or more, the CNN results were 100% concordant with the gold standard diagnoses. On average, autoimmune gastritis cases had 84.7% HALO-AI autoimmune gastritis AD and HP cases had 87.3% HALO-AI HP AD. The GI pathologists, general anatomic pathologists, and residents were on average, 100%, 86%, and 57% concordant with the gold standard diagnoses, respectively. CONCLUSIONS.­: A CNN can distinguish between cases of HPG and autoimmune gastritis with accuracy equal to GI pathologists.

Performance of a 50-gene next generation sequencing panel with post-centrifuge supernatant cytology fluid in non-small-cell lung cancer.

BACKGROUND: Liquid based cytology (LBC) specimens are increasingly utilized for molecular analysis, as results are comparable to molecular analysis performed on traditional specimens (biopsy or cell block). However, there are few studies demonstrating the long-term viability of DNA in LBC samples. METHODS: In this study, a 50-gene next generation sequencing (NGS) panel was performed on DNA isolated from post-centrifuged supernatant LBC samples of cases of non-small-cell lung carcinoma. Comparison was made to results of an identical NGS panel performed on a concurrent clinical sample (biopsy or cell block). Quality parameters including DNA concentration, total reads, amplicons with reads under 450 and 350, and variant allele fraction were also compared. For a subset of LBC samples, DNA was isolated after being held for varying extended lengths of time after collection (up to 41 days) at 5°C and results compared. RESULTS: Results of NGS mutation analysis were concordant between LBC samples and clinical samples. DNA concentration was on average higher in the LBC samples compared to the clinical samples. The remaining metrics were more variable, but illustrated the adequacy of LBC samples for NGS testing. DNA isolated from LBC samples held for longer periods of time was of good concentration. NGS analysis was successfully performed on all samples, with concordance with results of clinical samples. CONCLUSION: DNA isolated directly from LBC fluid is suitable for NGS analysis. DNA is also stable in LBC preservative for extended periods of time before isolation and NGS analysis can subsequently be successfully performed.

Giant Cell Tumor of Bone in Patients 55 Years and Older: A Study of 34 Patients.

OBJECTIVES: Most giant cell tumors of bone (GCTs) occur in patients aged 20 to 40 years. We analyzed features of GCT in patients 55 years or older. METHODS: GCTs were examined for fibrosis, matrix, cystic change, histiocytes, mitoses, and necrosis. Clinical/radiologic data were collected. RESULTS: Thirty-four (5%) of 710 GCTs occurred in patients older than 55 years (14/20 male/female; 56-83 years) in long bones (n = 24), vertebrae (n = 6), pelvis (n = 3), and metacarpal (n = 1). Imaging was classic in 26 of 27 cases; one case appeared malignant. Morphologic patterns included fibrosis (n = 29), bone formation (n = 19), cystic change (n = 8), necrosis (n = 8), foamy histiocytes (n = 7), and secondary aneurysmal bone cyst formation (n = 1). Mitoses ranged from 0 to 18 per 10 high-power fields. Six recurred; one patient developed metastasis. Four of five cases harbored H3F3A mutations. CONCLUSIONS: GCTs in patients 55 years or older share pathologic characteristics with those arising in younger adults. Fibrosis and reactive bone are common, potentially leading to diagnostic confusion in this population. No histologic features correlate with adverse outcome.

Extraskeletal myxoid chondrosarcoma with a t(9;16)(q22;p11.2) resulting in a NR4A3-FUS fusion.

Extraskeletal myxoid chondrosarcoma (EMC) is a rare neoplasm characterized by rearrangement of NR4A3. A t(9;22)(q22;q12), creating a fusion protein of EWSR1 and NR4A3, has been reported as a unique, recurring translocation in most cases. Reported variant translocations have resulted in fusion of NR4A3 with three other genes: TAF15, TCF12, and TFG. We report a case of EMC in a 59-year-old man who presented with a 6-month history of an enlarging mass in the proximal right thigh. The karyotype of fresh tissue from tumor taken at incisional biopsy revealed a t(9;16)(q22;p11.2). There was no evidence of an EWSR1 rearrangement by dual-color break-apart fluorescence in situ hybridization (FISH). Dual-color FISH probes revealed fusion of NR4A3 and FUS, a member of the TET family of genes, which includes EWSR1 and TAF15. Break-apart FISH probe results confirmed rearrangement of FUS. These findings show that a fusion product of FUS and NR4A3 may be an additional pathway to development of EMC.

Bizarre parosteal osteochondromatous proliferation: a new cytogenetic subgroup characterized by inversion of chromosome 7.

Bizarre parosteal osteochondromatous proliferation (BPOP) is a rare, benign osteocartilaginous lesion characterized by a mixture of immature bone, bland spindle cells, and irregular, hypercellular cartilage undergoing calcification. A t(1;17)(q32;q21) has been reported as a unique recurring translocation identified in seven cases. Inversion of chromosome 7, inv(7)(q22q32), has also recently been described in one case of BPOP. We report an additional case of inv(7) in a BPOP occurring on the distal radius in a 36-year-old woman who presented with a slow-growing mass on the right wrist. Metaphase karyotype analysis of fresh tissue from tumor taken at resection revealed an inv(7)(q22q32). A review of the literature identified two additional cases of inv(7) (q21.1q31.3 and q22.1q31.3), both paired with inv(6)(p25q15), bringing the total number of cases of inv(7) in BPOP to four. These data suggest inv(7) may be another characteristic cytogenetic abnormality associated with and possibly contributing to the development of BPOP.