Use and abuse of frozen section in the diagnosis of follicular thyroid lesions

The role of intraoperative frozen section in certain organ systems such as the thyroid continues to be problematic. In many cases, diagnoses are deferred or nonhelpful—“follicular lesion.” In the modern era, the widespread use of preoperative aspiration biopsy has allowed for more careful selection of patients who undergo thyroid surgery. In many cases, the fine-needle-aspiration (FNA) biopsy diagnosis can be definitive or can guide the specific surgical procedure. The literature supports our approach, which is summarized as follows: Intraoperative consultation is not needed on the intrathyroidal nodule if a preoperative FNA was definitive for papillary carcinoma. Frozen section is of no value in the intraoperative diagnosis of lesions diagnosed on FNA as “follicular neoplasm” or “Hürthle cell neoplasm” because the characterization of these lesions requires detailed analysis of the tumor capsule for the demonstration of capsular and/or vascular invasion—an analysis that is not practical in the intraoperative setting. Finally, intraoperative consultation including frozen section and intraoperative cytologic examination is most useful in those cases that are diagnosed as suspicious for papillary carcinoma by FNA, because the assessment of nuclear features needed for the definitive diagnosis is possible with intraoperative techniques in a significant number of cases.     

住院精神分裂症患者十年前后用药情况对比分析

目的对十年前后精神分裂症患者用药情况的变化进行调查分析.方法对十年前后两个五年段的各500份符合精神分裂症诊断标准的病历进行回顾性调查,并对各项指标进行对比分析.结果两组折算用药剂量经t检验差异无显著性(P>0.05);两组合并用药、合并抗胆碱药及疗效经χ2检验差异有显著性(P<0.01);十年后非典型抗精神病药物氯氮平在临床上的应用比例明显增大并上升为首位.结论十年前后两组抗精神病药的应用发生了明显变化,疗效好、副作用轻的非典型抗精神病药的应用比例明显增加.     

Osteogenic sarcoma of the maxilla.

Six cases of osteosarcoma of the maxilla are reported, including one case that was radiation-associated and one case that arose in Paget's disease. The literature on this entity is reviewed and the clinicopathologic features of this lesion in this unusual location are discussed.     

Left ventricular pseudoaneurysm after mitral valve replacement

Development of left ventricular pseudoaneurysm is a rare complication of mitral valve surgery and requires urgent surgical intervention. We describe a case of pseudoaneurysm of membranous septum following repeat mitral valve replacement with the use of multimodality imaging.     

Worrisome histologic alterations following fine-needle aspiration of benign parotid lesions

OBJECTIVE: To describe the histologic changes associated with preoperative fine-needle aspiration biopsies of benign parotid lesions and the features that distinguish these changes from malignant neoplasms. MATERIALS AND METHODS: Ten benign parotid lesions with a recent history of preoperative fine-needle aspiration were selected, including pleomorphic adenoma (4 cases), oncocytic adenoma (3 cases), myoepithelioma (1 case), Warthin tumor (1 case), and lymphoepithelial cyst (1 case). RESULTS: A spectrum of histologic alterations were observed. Alterations included squamous cell metaplasia (8 cases), infarction and necrosis (4 cases), subepithelial stromal hyalinization (3 cases), acute and chronic hemorrhage and inflammation with multinucleated giant cells (all cases), granulation tissue with subsequent fibrosis (all cases), cholesterol cleft formation (1 case), pseudoxanthomatous reaction (1 case), pseudocapsular invasion (1 case), and microcystic degeneration (2 cases). In cases with exuberant squamous metaplasia, necrosis, or subepithelial stromal hyalinization, a diagnosis of squamous cell carcinoma or low-grade mucoepidermoid carcinoma was seriously considered. CONCLUSIONS: Knowledge of a previous fine-needle aspiration procedure and awareness of its effects on histology of the subsequent parotidectomy specimens are necessary to avoid potential misdiagnosis.     

Loss of membrane expression of E-cadherin in leukemic erythroblasts

CONTEXT: The special societal relationships existing between various cell types in bone marrow suggests that there may be a link between the adhesive characteristics of hematopoietic cells and their maturation. Egress of the developing hematopoietic cells is also a highly regulated process governed by adhesive interactions. In leukemia, immature blasts are not retained within the marrow, suggesting a breakdown of adhesive mechanisms. Recent reports suggest that E-cadherin, an epithelial adhesion molecule, is expressed on erythroid precursors and megakaryocytes, but not on other hematopoietic marrow elements. OBJECTIVE: To characterize the expression pattern of E-cadherin in normal and leukemic erythroid precursors by immunohistochemistry in paraffin-embedded tissue and bone marrow aspirate smears. METHODS: Five normal bone marrow specimens from rib resections, 15 trephine bone marrow biopsy specimens, and 6 bone marrow aspirate smears from the iliac crest of patients with no known leukemia were selected. Fourteen bone marrow biopsy specimens from patients with erythroleukemia were also studied. Immunoperoxidase staining of paraffin-embedded tissue and air-dried aspirate smears for E-cadherin (1:200 dilution, HECD-1 clone) was performed using the avidin-biotin peroxidase technique. RESULTS: In paraffin-embedded bone marrow biopsy and rib specimens and in air-dried bone marrow aspirate smears, strong membrane expression of E-cadherin was seen in the normal erythroid precursors in all cases. In contrast, no membrane expression of E-cadherin was present in any of the bone marrow biopsy specimens from patients with erythroleukemia. CONCLUSIONS: Immunohistochemical detection of membrane expression of E-cadherin may be a useful tool for identification of erythroid precursors. Cells of erythroleukemia lack membrane expression of E-cadherin, in contrast to their normal counterparts. Further studies are needed to define the potential role of E-cadherin in the maturation of erythroid precursors and to ascertain the significance of loss of membrane expression of E-cadherin in erythroleukemia.     

Inflammatory pseudotumors (inflammatory fibrous polyps) of the esophagus

When they involve the gastrointestinal tract, inflammatory pseudotumors, composed of inflamed fibrous and granulation tissue, produce localized, frequently polypoid, masses. These rare lesions have been described in the stomach, small intestine, and colon. Only two have been previously reported in the esophagus. In this paper, 4 cases of inflammatory pseudotumor involving the esophagus are presented. These lesions usually occur in the esophagus as raised, occasionally pedunculated, masses and may be mistaken on radiologic examination and in the operating room for a neoplasm, usually a leiomyoma. Theories concerning pathogenesis of these lesions are considered and the differential diagnostic criteria are discussed.Dr. LiVolsi was formerly a National Cancer Institute Trainee in Surgical Pathology, Columbia University College of Physicians and Surgeons, New York.Supported in part by National Cancer Institute Traineeship 5 T 1 CA 5107-12 (Dr. LiVolsi).