Cytological findings for the diagnosis of primary thyroid mucosa-associated lymphoid tissue lymphoma by fine needle aspiration.

OBJECTIVE: We examined cytological findings for the diagnosis of primary thyroid mucosa-associated lymphoid tissue (MALT) lymphoma by fine needle aspiration. STUDY DESIGN: During the study period of 4 years, a total of 101 cases including 51 MALT lymphomas, 20 Hashimoto's thyroiditis (HT), and 30 diffuse large-cell B-cell lymphomas were cytologically examined. MALT lymphomas were divided into 44 common MALT and 7 MALT lymphomas with extreme plasmacytic differentiation (MALT-EPCD). RESULTS: (1) Small- to medium-sized cells displaying irregularly shaped nuclei with prominent nucleoli (ISN-PN) were neoplastic cells. (2) In the case of a frequency of plasma cells (PC) below 15%, the accuracy rate for distinguishing common MALT from HT was 97% for ISN-PN cell frequencies above 20% in combination with the presence of lymphoepithelial lesion clusters (LELC) and mountain range-like clusters (MRLC). The frequency of large-sized cells was below 15% in common MALT. (3) In the case of a frequency of PC above 15%, cases with a sum of PC and ISN-PN cells above 30% were MALT-EPCD. (4) MRLC were cell clusters derived from regions of follicular colonization, and LELC were cell clusters from lymphoepithelial lesions of MALT lymphomas. CONCLUSION: Useful cytological criteria for the diagnosis of thyroid primary MALT lymphoma, such as neoplastic cells and cell clusters, were defined.

Cytologic findings of primary thyroid MALT lymphoma with extreme plasma cell differentiation: FNA cytology of two cases.

We report fine-needle aspiration cytology (FNAC) obtained from two cases of mucosa-associated lymphoid tissue (MALT) lymphoma with extreme plasma cell differentiation. The patients were 61-year-old and 69-year-old Japanese women presenting with thyroid swelling. The smears contained numerous plasma cells, lymphocytes with plasma cell differentiation and scattered centrocyte-like (CCL) cells. In addition, one case demonstrated occasional atypical giant plasma cells. Occasional intranuclear inclusions (Dutcher bodies) of the plasma cells were observed in the other case. A few cytologic lymphoepithelial lesions-clusters (originating from lymphoepithelial lesions in histology) were also observed in one case. Plasma cells occupied approximately 10% in all of the lymphoid populations in FNAC specimens of Hashimoto thyroiditis, whereas, both cases demonstrated approximately 45% plasma cells and lymphocytes with plasma cell differentiation of all lymphocytes.The cytomorphologic findings of both cases were similar to those of plasmacytoma of the thyroid. However, immunohistochemical and flow cytometry studies demonstrated that both cases were MALT lymphoma with extreme plasma cell differentiation. From a therapeutic perspective, it is important to discriminate MALT lymphoma from plasmacytoma.

MALT type lymphoma demonstrating prominent plasma cell differentiation resembling fibrous variant of Hashimoto's thyroiditis: a three case report.

Fibrous variant of Hashimoto's thyroiditis (HT) is characterized by marked fibrous replacement of one third or more of the thyroid parenchyma. We present here three cases of mucosa associated lymphoid tissue (MALT) type lymphoma demonstrating prominent plasma cell differentiation resembling fibrous variant of HT. Histologically, thyroid structures were disturbed by a diffuse and focally nodular infiltration by mature plasma cells and cells with plasma cell differentiation against a background of prominent hyalinosis. In addition, scattered centrocyte-like (CCL) cells and lymphoepithelial lesions were observed in all three lesions. A portion of the resected specimens in all three cases exhibited HT. However, immunohistochemical study demonstrated that the plasma cells and CCL-cells of these three lesions had monotypic intracytoplasmic kappa light chain. Moreover, these three lesions demonstrated a clonal band on polymerase chain reaction assay for the immunoglobulin heavy chain gene. To avoid underdiagnosis, we emphasize that careful attention should be paid to these immunological features as well as to morphological findings.

HIV-unrelated benign lymphoepithelial cyst of the parotid glands containing lymphoepithelial lesion--like structures: a report of 3 cases.

Benign lymphoepithelial cyst (BLC) of the salivary gland is uncommon. Among report of these lesions, there were no previous cases of lymphoepithelial lesion (LeL) in human immunodeficiency virus type-1 (HIV-1) unrelated BLC. This study reports 3 cases of HIV-unrelated BLC containing LeL-like structures. Pathologically, 3 lesions were characterized by cuboidal epithelial-lined, cystic spaces, numerous lymphoid follicles, and dense lymphoplasmacytoid infiltrate. Moreover, small lymphocytes invaded the epithelial clusters forming LeL-like structures. Histological findings of 3 lesions resembled marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type. However, staining with CD3, CD5, and CD20 demonstrated the mixed nature of small lymphocytes invading the epithelial clusters (LeLlike structures). Moreover, there were no CD43+ B-lymphocytes in any of the cases. The polytypic nature of B-lymphocytes was demonstrated by immunohistochemistry and polymerase chain reaction. The 3 cases indicate that HIV-unrelated BLC should be added to the differential diagnosis of MALT-type lymphoma involving the parotid glands.

Angiogenic factors in normal endometrium and endometrial adenocarcinoma.

In the endometrium, angiogenesis plays important roles not only in tumor growth but also in the menstrual cycle. The purpose of the present paper was to investigate immunohistochemically the correlation between angiogenic factor expression and angiogenic score in normal and neoplastic endometrium. Immunohistochemical staining for vascular endothelial growth factor (VEGF), angiopoietin (Ang)-1, Ang2, Tie2, CD34 and CD105 was performed on formalin-fixed and paraffin-embedded tissues from 31 normal endometrium and 85 endometrial adenocarcinoma. VEGF, Ang1, Ang2 and Tie2 expression was localized in the cytoplasm of glandular and tumor cells. The levels of each angiogenic factor were different in the phases of the menstrual cycle and each layer of normal endometrium. In general, VEGF and Tie2 expression was higher in adenocarcinoma than in normal epithelial cells. Conversely, Ang1 and Ang2 expression was higher in normal epithelium than in adenocarcinoma. The angiogenic score (CD105/CD34) tended to be higher in the adenocarcinoma than in the normal epithelium. It is suggested that the angiogenic pathway and the role of these factors seem to differ between normal tissue and carcinoma of the endometrium.

Küttner's tumor of the submandibular glands: report of five cases with fine-needle aspiration cytology.

Küttner's tumor (KT) is a benign tumor-like lesion of the salivary gland that mimics neoplasm clinically because of presentation as a hard mass. Recently, the histomorphological and immunohistochemical findings of this lesion have been analyzed, and differential diagnostic problems relating to salivary gland lymphoma have been discussed. However, currently there is little information on the cytological findings of those lesions. We present cytological findings from five such cases using fine-needle aspiration cytology (FNAC). FNAC of this lesion may present a diagnostic challenge to the cytologist as lesions share some cytologic features with inflammatory process containing numerous lymphoid cells. Smears obtained from two cases contained moderate to large numbers of lymphoid cells without definite cytological atypia, scattered ductal structures, and acinar cell clusters. The remaining three cases showed low cellularity probably attributable to fibrosis that made it difficult to aspirate the cellular element. FNAC findings of scattered ductal structures surrounded by collagens and infiltrated by a mixed population of lymphoid cells, not specific for KT, are highly suggestive of the diagnosis with the appropriate clinical findings. However, a portion of cytological specimens of KT containing relatively large numbers of lymphoid cells should be differentiated from malignant lymphoma arising from the submandibular gland.