Archives of pathology & laboratory medicine
-
Arch. Pathol. Lab. Med. · Feb 2006
Immunoreactivity of MIC2 (CD99) and terminal deoxynucleotidyl transferase in bone marrow clot and core specimens of acute myeloid leukemias and myelodysplastic syndromes.
MIC2 ("thymus leukemia") antigen has been shown to be expressed by T cells and monocytes, as well as B cells and granulocyte-lineage cells. It is most intensely expressed by the most immature thymus T-lineage cells and is more intensely expressed by CD34-positive/CD33-positive myeloid cells (compared to more mature myeloid cells) and the earliest CD34-positive/CD10-positive B-cell precursor cells (compared to cells of later B-cell precursor stages). CD99 (MIC2) is characteristically expressed in precursor B- and T-cell lymphoblastic lymphomas/leukemias, as well as in Ewing sarcoma/primitive neuroectodermal tumors (ES/PNET). It has also been shown to be expressed in a few terminal deoxynucleotidyl transferase (TdT)-positive myeloid processes, but has been uniformly negative in TdT-negative myeloid processes. A more recent study showed that 43% of acute myeloid leukemias (AMLs) and 55% of chloromas express CD99, concluding that CD99 is commonly expressed in AML and rarely seen in myeloproliferative disorders, myelodysplastic syndromes, or normal bone marrow. Although this study speculated that MIC2 expression was probably not limited to TdT-positive AML, there was no comparison with TdT reactivity in this study. ⋯ In contrast to a previous study, CD99 expression was not restricted to TdT-positive hematologic proliferations. In particular, the CD99-positive M3 and M7 AMLs were TdT negative. An M5 AML may likely be excluded based on a uniform TdT-negative/CD99-negative immunophenotype. In addition, in our experience, CD99 should be routinely evaluated on bone marrow clots, owing to decreased reactivity or loss of reactivity in rapid decalcifying (RDO) solution-decalcified specimens.
-
Arch. Pathol. Lab. Med. · Jan 2006
Case ReportsRenal failure and nephrocalcinosis associated with oral sodium phosphate bowel cleansing: clinical patterns and renal biopsy findings.
Acute renal failure (ARF) is rarely reported after bowel preparation with sodium phosphate. We report a patient with mild Crohn disease (in remission), without history of renal disease, and with normal baseline renal function, who developed ARF 14 days after bowel preparation for colonoscopy with oral sodium phosphate. A renal biopsy showed multifocal calcium phosphate deposition in the renal tubules against a background of diffuse chronic tubulointerstitial injury. ⋯ At the time of presentation, the serum calcium and phosphate levels were normal. The renal biopsies in each of these patients showed nephrocalcinosis as the possible cause of ARF. The renal failure improved at least partially in most of these patients, but persisted in rare cases.
-
Skin cancers are the most common malignancies in this country. Treatment of these tumors often involves assessment of margins, which may be performed by frozen section. ⋯ Frozen sections play a vital role in the evaluation of margins of basal cell carcinomas and squamous cell carcinomas. The role of frozen sections in evaluation of soft tissue tumors is controversial. With rare exception, they have no role in the evaluation of melanocytic tumors.