The liver is a major store of glycogen and is essential in maintaining systemic glucose homeostasis. In healthy individuals, glycogen synthesis and breakdown in the liver are tightly regulated. ...Abnormal glycogen metabolism results in prominent pathological changes in the liver, often manifesting as hepatic glycogenosis or glycogen inclusions. This can occur in genetic glycogen storage disease or acquired conditions with insulin dysregulation such as diabetes mellitus and non-alcoholic fatty liver disease or medication effects. Some primary hepatic tumors such as clear cell hepatocellular carcinoma also demonstrate excessive glycogen accumulation. This review provides an overview of the pathological manifestations and molecular mechanisms of liver diseases associated with abnormal glycogen accumulation.
Newer radiotherapy techniques, such as stereotactic body radiation, have been increasingly used as part of the treatment of cholangiocarcinomas, particularly as a bridge to liver transplantation. ...Although conformal, these high-dose therapies result in tissue injury in the peritumoral liver tissue. This retrospective study characterized the morphologic changes in the liver after stereotactic body radiation in a series of liver explant specimens with perihilar cholangiocarcinoma. The morphologic changes in the irradiated zone were compared against the nonirradiated background liver parenchyma to control for chemotherapy-related changes. Of the 21 cases studied, 16 patients (76.2%) had underlying primary sclerosing cholangitis, and 13 patients (61.9%) had advanced liver fibrosis. The average duration between completion of radiotherapy and liver transplantation was 33.4 weeks (range: 6.29 to 67.7). Twelve patients (57.1%) had no residual tumor in the liver. The most frequent histologic changes in the peritumoral irradiated liver tissue were sinusoidal congestion (100%), sinusoidal edematous stroma (100%), and hepatocellular atrophy (100%), followed by partial/complete occlusion of central veins (76.2%), sinusoidal cellular infiltrates (76.2%), and hepatocyte dropout (66.7%). The findings in the radiated areas were more extensive than in the background liver ( P <0.01). Sinusoidal edematous stroma was striking and dominated the histologic findings in some cases. Over time, there was less sinusoidal congestion but more hepatocyte dropout (r s =-0.54, P =0.012 and r s =0.64, P =0.002, respectively). Uncommon findings, such as foam cell arteriopathy in the liver hilum, were also observed. In summary, postradiation liver specimens have distinctive morphologic findings.
A 38-year-old, previously healthy man presented with blood-stained saliva and epistaxis. A 3 mm nasopharyngeal lesion was found. A biopsy was performed and microscopic examination revealed a Kaposi ...sarcoma. The patient was subsequently found to be positive for human immunodeficiency virus (HIV). The diagnosis of Kaposi sarcoma in the presence of HIV infection advanced his disease to Acquired Immunodeficiency Syndrome (AIDS). Primary manifestation of Kaposi sarcoma in the nasopharynx is extremely rare. The histologic differential diagnosis of Kaposi sarcoma in this unusual site, especially without the clinical history of immunosuppression, is broad. Awareness that nasopharynx can be a primary involvement site of Kaposi sarcoma and serves as index diagnosis of AIDS is important given its serious clinical implication.
Histological subtyping of hepatocellular carcinoma (HCC) is challenging in the presence of histological heterogeneity, where distinctly different morphological patterns are present within the same ...tumor. Current approaches rely on percent cut-offs. We hypothesized that morphologic intratumor heterogeneity is a non-random biological feature and that incorporating recurrent patterns would improve histological subtyping of HCC. Resected HCC were studied and the overall frequency of morphologic intratumor heterogeneity was 45% in 242 specimens. Steatohepatitic HCC (SH-HCC) had the highest frequency of morphologic intratumor heterogeneity (91%); this was confirmed in additional cohorts of SH-HCC from different medical centers (overall frequency of 78% in SH-HCC). Morphologic intratumor heterogeneity in SH-HCC showed distinct and recurrent patterns that could be classified as early, intermediate, and advanced. Incorporating these patterns into the definition of SH-HCC allowed successful resolution of several persistent challenges: the problem of the best cut-off for subtyping SH-HCC, the problem of the relationship between SH-HCC and scirrhous HCC, and the classification for HCC with abundant microvesicular steatosis. This approach also clarified the relationship between SH-HCC and CTNNB1 mutations, showing that CTNNB1 mutations occur late in a subset of SH-HCC. In summary, there is a high frequency of morphologic intratumor heterogeneity in HCC. Incorporating this finding into histological subtyping resolved several persistent problems with the SH-HCC subtype.
We present a 51 year old female patient with a pelvic desmoplastic small round cell tumor with an unusual immunohistochemical profile, including absence of significant cytokeratin expression, ...complete negativity for desmin and widespread loss of nuclear INI-1 expression (>90% of tumor cells). The neoplastic cells were positive for epithelial membrane antigen (EMA), vimentin, and WT-1 (antibody against the C-terminus). The tumor showed classic histopathological features with no rhabdoid cells. Fluorescent in situ hybridization revealed EWSR1 gene rearrangement and absent SYT gene rearrangement. Reverse transcriptase polymerase chain reaction showed presence of EWSR1-WT1 transcript.
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