GLUT1 Immunohistochemistry Is a Highly Sensitive and Relatively Specific Marker for Erythroid Lineage in Benign and Malignant Hematopoietic Tissues.

OBJECTIVES: Glucose transporter 1 (GLUT1), a glucose transporter, is an abundant protein in erythrocytes with expression beginning early in erythropoiesis. We sought to evaluate the utility of GLUT1 immunohistochemistry (IHC) as a diagnostic marker for identifying erythroid differentiation in hematopoietic tissues, including neoplastic erythroid proliferations. METHODS: A variety of benign and neoplastic bone marrow biopsy specimens containing variable proportions of erythroid precursors were selected (n = 46, including 36 cases of leukemia). GLUT1 IHC was performed using a commercially available polyclonal antibody. Each case was evaluated for staining of erythroid precursors, nonerythroid hematopoietic cells, and blasts. A GATA1/GLUT1 double stain was performed on one case to confirm coexpression of GLUT1 on early erythroid precursors. Staining was compared with other erythroid markers, including glycophorin C. RESULTS: GLUT1 demonstrated strong membranous staining in erythroid precursors of all cases, which was restricted largely to the erythroid lineage. Of the 36 leukemia cases, all 6 cases of pure erythroid leukemia and both cases of therapy-related acute myeloid leukemia with erythroid differentiation showed positive GLUT1 staining in blasts. Otherwise, only lymphoblasts in B-lymphoblastic leukemia showed weak to moderate granular cytoplasmic staining (four of five cases). CONCLUSIONS: GLUT1 IHC is a highly sensitive and relatively specific marker for erythroid lineage in benign and neoplastic bone marrow biopsy specimens.

Histiocytic Necrotizing Lymphadenitis Involving the Neck: Radiology-Pathology Correlation.

Histiocytic necrotizing lymphadenitis is an uncommon autoimmune condition characterized by fever, leukopenia, and neck swelling. Diagnostic imaging, including ultrasound and CT, typically demonstrates conglomerates of enlarged cervical lymph nodes with hypervascular cortices and areas of necrosis. Ultimately, the diagnosis is confirmed with the histopathologic findings of paracortical coagulative necrosis with karyorrhectic debris, abundant histiocytes, and absence of neutrophils. Other potential etiologies, such as other causes of infectious lymphadenitis, tuberculosis, lymphoma, and systemic lupus erythematosus, must be excluded. These features are exemplified in this sine qua non radiology-pathology correlation article.

Dihydropyrimidine dehydrogenase deficiency as a cause of fatal 5-Fluorouracil toxicity.

5-Fluorouracil (5-FU), in combination with other cytotoxic drugs, is commonly used to treat a variety of cancers. Dihydropyrimidine dehydrogenase (DPD) catalyzes the first catabolic step of the 5-FU degradation pathway, converting 80% of 5-FU to its inactive metabolite. Approximately 0.3% of the population demonstrate complete DPD deficiency, translating to extreme toxicity of 5-FU. Here we present a case of a patient who had a fatal outcome after treatment with 5-FU who was found to have an unknown DPD deficiency discovered at autopsy.

Dedifferentiated Chondrosarcoma of the Larynx.

Primary dedifferentiated chondrosarcoma occurring in the larynx is a rare head and neck malignancy. The cases reported in the literature suggest male gender predilection and variable clinical outcomes ranging from disease-free survival to disease-related death. Although a calcified matrix is suggestive of chondrosarcoma, the dedifferentiated component is not readily appreciated on conventional imaging modalities and thorough tissue sampling is necessary for confirming the diagnosis. Histologically, there is an abrupt transition from a well-differentiated chondrosarcoma to a high-grade spindle cell component, which can show focal heterologous differentiation. These features are exemplified in this sine qua non radiology-pathology correlation article.

Dihydropyrimidine dehydrogenase deficiency as a cause of fatal 5-Fluorouracil toxicity

5-Fluorouracil (5-FU), in combination with other cytotoxic drugs, is commonly used to treat a variety of cancers. Dihydropyrimidine dehydrogenase (DPD) catalyzes the first catabolic step of the 5-FU degradation pathway, converting 80% of 5-FU to its inactive metabolite. Approximately 0.3% of the population demonstrate complete DPD deficiency, translating to extreme toxicity of 5-FU. Here we present a case of a patient who had a fatal outcome after treatment with 5-FU who was found to have an unknown DPD deficiency discovered at autopsy.