The Histopathology of Cold Agglutinin Disease-Associated B-Cell Lymphoproliferative Disease.

OBJECTIVES: Primary cold agglutinin disease is a type of autoimmune hemolytic anemia caused by circulating antibodies against I antigen, a carbohydrate expressed on most cells, including red blood cells. The underlying disease has been characterized in recent years as a distinct B-cell lymphoproliferative disease of the bone marrow, occurring mostly in the elderly. The disease has been now been included as a separate entity in the most recent classifications of mature B-cell neoplasms. METHODS: A review of the characteristics of cold agglutinin disease is provided, with an emphasis on the pathology features. RESULTS: A detailed description of the histopathology, immunophenotype, and genetics of cold agglutinin disease is provided and compared to other B-cell lymphoproliferative diseases in the bone marrow with similar features. CONCLUSIONS: Recognition of the pathology features of cold agglutinin disease allows to distinguish it from other diseases, especially lymphoplasmacytic lymphoma and marginal zone lymphoma.

Deep Learning Accurately Quantifies Plasma Cell Percentages on CD138-Stained Bone Marrow Samples.

The diagnosis of plasma cell neoplasms requires accurate, and ideally precise, percentages. This plasma cell percentage is often determined by visual estimation of CD138-stained bone marrow biopsies and clot sections. While not necessarily inaccurate, estimates are by definition imprecise. For this study, we hypothesized that deep learning can be used to improve precision. We trained a semantic segmentation-based convolutional neural network (CNN) using annotations of CD138+ and CD138- cells provided by one pathologist on small image patches of bone marrow and validated the CNN on an independent test set of image patches using annotations from two pathologists and a non-deep learning commercial software. On validation, we found that the intraclass correlation coefficients for plasma cell percentages between the CNN and pathologist #1, a non-deep learning commercial software and pathologist #1, and pathologists #1 and #2 were 0.975, 0.892, and 0.994, respectively. The overall results show that CNN labels were almost as accurate as pathologist labels at a cell-by-cell level. Once satisfied with performance, we scaled-up the CNN to evaluate whole slide images (WSIs), and deployed the system as a workflow friendly web application to measure plasma cell percentages using snapshots taken from microscope cameras.

Plaque-like demyelination in acute disseminated encephalomyelitis (ADEM) - an autopsy case report.

AIMS/BACKGROUND: The pattern of demyelination in the scant autopsy literature on acute disseminated encephalomyelitis (ADEM) is described as perivenous sleeves. We report an unusual neuropathological presentation of ADEM, also known as postinfectious or perivenous encephalomyelitis. CASE HISTORY: A 19-yearold female patient presented with headache and myalgias, followed by subacute onset of lethargy, confusion, left hemiparesis and dysphasia after an interval of 4 - 5 days. On MRI, extensive subcortical white matter lesions were seen and a diagnosis of ADEM was made after other causes were excluded. The patient received intravenous methylprednisolone and plasma exchange. Neurological symptoms remained stable over the length of the hospital stay (1 month). The patient passed away due to non-neurologic causes. RESULTS: On autopsy, the brain showed extensive, confluent, plaque-like demyelinating lesions with a striking selectivity for the subcortical white matter sparing the U-fibers. No lesions were discernible in the cortex, the deep grey matter, the cerebellum, the spinal cord or the optic nerves on LFB-stained sections. Only one lesion extended to the periventricular area in the right occipital lobe. Some lesions had a scalloped border and foci of inhomogeneous demyelination, suggestion coalescence of smaller lesions. Histologically, all lesions were of the same age, coupling near complete demyelination with relative preservation of axons, along with scant perivascular lymphohistiocytic cuffing, dense infiltration by foamy macrophages, and prominent gliosis. CONCLUSION: The morphology of individual demyelinating< lesions is indistinguishable from the lesions in a new onset case of multiple sclerosis (MS) and adds to the autopsy literature on overlapping neuropathological findings in ADEM and multiple sclerosis.