Adenocarcinoma ; diagnostic imaging ; metabolism ; pathology ; surgery ; Carcinoembryonic Antigen ; metabolism ; Diagnosis, Differential ; Follow-Up Studies ; Humans ; Keratin-20 ; metabolism ; Male ; Microfilament Proteins ; metabolism ; Middle Aged ; Phosphopyruvate Hydratase ; metabolism ; Thymus Neoplasms ; diagnostic imaging ; metabolism ; pathology ; surgery ; Tomography, X-Ray Computed

Child ; Female ; Head and Neck Neoplasms ; diagnosis ; pathology ; surgery ; Humans ; Parathyroid Neoplasms ; diagnosis ; pathology ; surgery ; Thymus Gland ; pathology ; surgery ; Thymus Neoplasms ; diagnosis ; pathology ; surgery

OBJECTIVETo study the clinicopathologic features of primary thymic extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT).

METHODSThe clinical and pathologic findings were evaluated in 3 cases of biopsy confirmed thymic MALT lymphoma. The clincopathologic features, treatment and prognosis were discussed and literatures reviewed.

RESULTSOne male and two female patients presented with asymptomatic mediastinal masses with a history of Sjögren syndrome. They were aged 36, 35 and 41 years respectively, and only one patient had B symptoms. Grossly, all three tumors were encapsulated and had multiple variable-sized cysts on cut-surface. Histopathologically, the normal thymic lobular architecture was effaced by abnormal dense lymphoid infiltration. Prominent lymphoepithelial lesions were formed by centrocyte-like cells infiltrating and expanding Hassall's corpuscles and epithelial cyst lining. All cases showed apparent plasmacytic differentiation. Immunohistochemically, the tumor cells were positive for CD20, CD79a, bcl-2 and negative for CD3, CD5, cyclin D1, CD43, CD10, bcl-6, and CD23. The plasma cells showed kappa light chain restriction. Immunoglobulin heavy chain rearrangement in three cases was confirmed by PCR. All patients were at early stage and received routine chemotherapy with or without radiotherapy after surgical removal. All patients achieved complete remission with 24, 18 and 3 months follow-up, respectively.

CONCLUSIONSPrimary thymic MALT lymphoma may be a rare distinctive lymphoma. It can be diagnosed by HE and immunohistochemical study and should be differentiated from reactive lymphoid proliferation, other types of lymphoma and mediastinal thymoma.

Adult ; Antibodies, Monoclonal, Murine-Derived ; therapeutic use ; Antigens, CD20 ; metabolism ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Cyclophosphamide ; therapeutic use ; Diagnosis, Differential ; Doxorubicin ; therapeutic use ; Female ; Follow-Up Studies ; Gene Rearrangement, B-Lymphocyte, Heavy Chain ; Humans ; Immunoglobulin Heavy Chains ; genetics ; Keratin-19 ; metabolism ; Lymphoma, B-Cell, Marginal Zone ; drug therapy ; genetics ; metabolism ; pathology ; surgery ; Male ; Prednisone ; therapeutic use ; Pseudolymphoma ; pathology ; Thymus Hyperplasia ; pathology ; Thymus Neoplasms ; drug therapy ; genetics ; metabolism ; pathology ; surgery ; Vincristine ; therapeutic use

Adult ; CD5 Antigens ; metabolism ; Carcinoma, Papillary ; metabolism ; pathology ; Carcinoma, Squamous Cell ; metabolism ; pathology ; surgery ; Choristoma ; metabolism ; pathology ; Diagnosis, Differential ; Female ; Hamartoma ; metabolism ; pathology ; Humans ; Proto-Oncogene Proteins c-kit ; metabolism ; Thymoma ; metabolism ; pathology ; Thymus Gland ; pathology ; Thymus Neoplasms ; metabolism ; pathology ; Thyroid Neoplasms ; metabolism ; pathology ; surgery ; Thyroidectomy ; methods

Adult ; Antigens, CD20 ; metabolism ; Carcinoma ; metabolism ; pathology ; DNA Nucleotidylexotransferase ; metabolism ; Diagnosis, Differential ; Female ; Follow-Up Studies ; Humans ; Keratins ; metabolism ; Lymphoma ; metabolism ; pathology ; Male ; Middle Aged ; Necrosis ; Seminoma ; metabolism ; pathology ; Thymoma ; metabolism ; pathology ; surgery ; Thymus Neoplasms ; metabolism ; pathology ; surgery ; Tuberculosis ; pathology

The association of thymoma with pure red cell aplasia has been well documented, but amegakaryocytic thrombocytopenia is not a recognized paraneoplastic syndrome complicating thymoma. We report a case of thymoma-complicated pure red cell aplasia and amegakaryocytic thrombocytopenia in a 73-yr-old woman. Pure red cell aplasia was diagnosed seven months after the detection of thymoma. One year after the diagnosis of pure red cell aplasia and seven months after thymectomy, bone marrow aspiration and biopsy showed an absence of megakaryocytes, marked erythroid hypoplasia with normal myeloid series. A diagnosis of amegakaryocytic thrombocytopenia and pure red cell aplasia was made. Oral steroid maintenance therapy resulted in recovery of platelet count. She has still transfusion-dependant anemia but platelet and neutrophil counts had been maintained in normal range for more than five months, until the last follow-up. We think that autoreactive T cells may induce a clinical autoimmune response even after eradication of thymoma, and aplastic anemia as a late complication following thymectomy was described in previous cases. This patient also has to be under a close observation because of the possibility to evolve into aplastic anemia.
Aged ; Bone Marrow/pathology ; Female ; Humans ; Imidazoles/therapeutic use ; Megakaryocytes/pathology ; Pregnadienetriols/therapeutic use ; Red-Cell Aplasia, Pure/complications/*diagnosis ; Thrombocytopenia/*diagnosis/drug therapy/*etiology ; Thymectomy/*adverse effects ; Thymoma/*complications/diagnosis/surgery ; Thymus Neoplasms/*complications/diagnosis/surgery

Aged ; CD5 Antigens ; metabolism ; Carcinoma, Basal Cell ; metabolism ; pathology ; surgery ; Diagnosis, Differential ; Humans ; Lung Neoplasms ; pathology ; Male ; Mediastinal Cyst ; pathology ; Middle Aged ; Proto-Oncogene Proteins c-kit ; metabolism ; Thymoma ; pathology ; Thymus Neoplasms ; metabolism ; pathology ; surgery

Diagnosis, Differential ; Fibroadenoma ; metabolism ; pathology ; surgery ; Humans ; Keratins ; metabolism ; Lipoma ; metabolism ; pathology ; surgery ; Male ; Middle Aged ; Mucin-1 ; metabolism ; Neoplasms, Multiple Primary ; metabolism ; pathology ; surgery ; Thymoma ; metabolism ; pathology ; surgery ; Thymus Neoplasms ; metabolism ; pathology ; surgery ; Vimentin ; metabolism

Breast metastasis from nonmammary malignant neoplasms is uncommon, and it accounts for approximately 2% of all breast tumors. Distant metastasis of thymoma is very rare, and especially to extrathorcic areas. We report a female who had a metastatic thymoma in her breast 20 years after undergoing resection for a non-invasive thymoma. She presented with a palpable mass in her left breast. Mammography and ultrasonogram showed a lobular mass at the anterior glandular portion. Histological examination after surgical excision revealed a metastatic thymoma.
Breast Neoplasms/diagnosis/*secondary/surgery ; Female ; Humans ; Magnetic Resonance Imaging ; Middle Aged ; Thymoma/diagnosis/*secondary/surgery ; Thymus Neoplasms/diagnosis/*pathology/surgery ; Tomography, X-Ray Computed ; Ultrasonography, Mammary

OBJECTIVETo study the clinicopathological and immunohistochemical features of ectopic hamartomatous thymoma (EHT), and to discuss its histogenesis.

METHODSThe clinical and pathologic features of two EHT cases of were evaluated. Immunohistochemical study was performed by LSAB method using a panel of antibodies including AE1/AE3, CK5, CK7, CK8, CK20, EMA, vimentin, CD5, CD10, alpha-SMA, calponin, desmin, CD34, S-100 protein, CD57, GFAP, TTF-1 and CD99.

RESULTSBoth cases occurred in males aged 20 years and 40 years respectively. Each patient presented with a solitary mass, one located in the suprasternal fossa and the other in the left supraclavicular region for a period of 6 months and 2 months respectively. Grossly, the masses were well-circumscribed with spherical and ovoid appearance, measuring 5 cm and 3 cm in maximum diameter respectively. On cut section, they were gray-white in color and of soft consistency. Histologically, both tumors were composed of a mixture of spindle cells, epithelial cells and mature adipose tissue. The spindle cells element accounted 85% and 70% each in the two cases. They resembled fibroblasts in morphology and were arranged frequently in fascicular, woven or storiform patterns. Epithelial cells element represented nearly 10% in both cases. Most of the epithelial cells had a non-keratinization squamous appearance. They formed small solid islands and adamantinoma-like "nastomosing cords", or appeared as lining cells in large cystic spaces. In focal areas, glandular differentiation presented as small glands. A transition between the spindle cell and epithelium components could be also identified in some areas. Mature adipose tissue was irregularly distributed in the two tumors, about < 5% and 20% respectively. Immunohistochemically, the epithelial element expressed AE1/AE3, CK5, CK7, CK8 and EMA, whereas the spindle component expressed AE1/AE3, CK5, CK7, CK8, vimentin, CD10, CD34, alpha-SMA, MSA, and calponin. Both elements were negative for CK20, TTF-1, desmin, S-100 protein, CD57, GFAP and CD99.

CONCLUSIONSEHT is a benign tumor that occurs predominantly in the lower neck region of young to middle-aged males. Immunohistochemical study revealed myoepithelial differentiation of the spindle cells, suggesting EHT is a mixed tumor composed of epithelial and myoepithelial cells. EHT possibly originates from the remnants of cervical sinus of His, and therefore, may be renamed as branchial anlage mixed tumor.

Adult ; Anion Exchange Protein 1, Erythrocyte ; metabolism ; Choristoma ; metabolism ; pathology ; surgery ; Diagnosis, Differential ; Hamartoma ; Humans ; Keratins, Type II ; metabolism ; Lymphatic Diseases ; metabolism ; pathology ; surgery ; Male ; Mucin-1 ; metabolism ; Thymoma ; metabolism ; pathology ; surgery ; Thymus Neoplasms ; metabolism ; pathology ; surgery ; Vimentin ; metabolism