Metallic implant-associated lymphomas are extremely rare. Only seven cases have been reported in association with knee joint arthroplasty, and all tumors were large B-cell lymphomas. This report is the first case of anaplastic large cell lymphoma occurring after total knee replacement arthroplasty. An 80‑year‑old female patient was admitted because of right knee pain for 2 years. She had undergone total knee replacement arthroplasty 10 years prior. Computed tomography showed an irregular osteolytic lesion in the right lateral femoral condyle, adjacent to the metallic prosthesis. Histologic findings reveal sheets of anaplastic tumor cells that were positive for CD2, CD4, CD5, CD43, and CD30 but negative for CD3, CD20, CD15, and anaplastic lymphoma kinase. Epstein-Barr encoding region in situ hybridization was negative. Analysis of T-cell receptor γ gene rearrangement studies using BIOMED-2–based multiplex polymerase chain reaction confirmed monoclonal T cell proliferation. The woman was finally diagnosed with ALK-negative anaplastic large cell lymphoma.

Intrathyroidal metastasis of tonsillar squamous cell carcinoma is rare. To date, only six cases have been reported in the literature. This case was unusual and presented with thyromegaly before the diagnosis of the primary tumor. A 55-year-old male patient was suspected to have a primary thyroid tumor with nodal metastasis. The thyroid gland was diffusely enlarged, with no discernible mass. Histologically, the thyroid parenchyma revealed extensive endolymphatic tumor emboli, which were positive for p40 and p16 in a background of chronic lymphocytic thyroiditis. Positron emission tomography–computed tomography revealed hypermetabolic activity in the right tonsillar region. Tonsillar biopsy revealed human papillomavirus–positive squamous cell carcinoma. The present case is the first reported case of intrathyroidal metastasis of tonsillar squamous cell carcinoma with an initial clinical presentation of thyroid enlargement before the primary tumor of tonsillar cancer was diagnosed.

Immunoglobulin G4 (IgG4)-related kidney disease is a chronic immune-mediated fibro-inflammatory disorder characterized by multiple organ infiltration with IgG4-positive plasma cells, storiform fibrosis, and obliterative phlebitis or tumefactive lesions. Previous studies have explored IgG4-related kidney disease, increasing our understanding of its clinical manifestations, and pathological and radiologic findings. However, IgG4-related kidney disease can be misdiagnosed since it mimics malignancies. We report a case of a 77-year-old Korean man diagnosed with IgG4-related kidney disease with membranous proliferative glomerulonephritis, presenting with a renal pelvic mass suspected of being malignant.

Immunoglobulin G4 (IgG4)-related kidney disease is a chronic immune-mediated fibro-inflammatory disorder characterized by multiple organ infiltration with IgG4-positive plasma cells, storiform fibrosis, and obliterative phlebitis or tumefactive lesions. Previous studies have explored IgG4-related kidney disease, increasing our understanding of its clinical manifestations, and pathological and radiologic findings. However, IgG4-related kidney disease can be misdiagnosed since it mimics malignancies. We report a case of a 77-year-old Korean man diagnosed with IgG4-related kidney disease with membranous proliferative glomerulonephritis, presenting with a renal pelvic mass suspected of being malignant.

No abstract available.
Neoplasms, Plasma Cell ; Plasma Cells ; Plasma

No abstract available.
Lymphoma ; Lymphoma, T-Cell ; T-Lymphocytes

Extranodal natural killer (NK)/T-cell lymphoma, nasal type (NKTCL), is a malignant disorder of cytotoxic lymphocytes of NK or T cells. It is an aggressive neoplasm with a very poor prognosis. Although extranodal NKTCL reportedly has a strong association with Epstein-Barr virus, the molecular pathogenesis of NKTCL has been unexplored. The recent technological advancements in next-generation sequencing (NGS) have made DNA sequencing cost- and time-effective, with more reliable results. Using the Ion Proton Comprehensive Cancer Panel, we sequenced 409 cancer-related genes to identify somatic mutations in five NKTCL tissue samples. The sequencing analysis detected 25 mutations in 21 genes. Among them, KMT2D, a histone modification-related gene, was the most frequently mutated gene (four of the five cases). This result was consistent with recent NGS studies that have suggested KMT2D as a novel driver gene in NKTCL. Mutations were also found in ARID1A, a chromatin remodeling gene, and TP53, which also recurred in recent NGS studies. We also found mutations in 18 novel candidate genes, with molecular functions that were potentially implicated in cancer development. We suggest that these genes may result in multiple oncogenic events and may be used as potential bio-markers of NKTCL in the future.
Chromatin Assembly and Disassembly ; Herpesvirus 4, Human ; High-Throughput Nucleotide Sequencing ; Histones ; Lymphocytes ; Lymphoma* ; Prognosis ; Protons ; Sequence Analysis, DNA ; T-Lymphocytes

BACKGROUND: Follicular lymphomas present with various immunohistologic patterns. The immunohistochemical markers used in the diagnosis of follicular lymphoma show variable degrees of sensitivity and specificity, and thus, additional germinal center markers are required. Smad1 has been reported to be overexpressed in follicular lymphoma, but little is known regarding the expression patterns of Smad proteins in human lymphoid tissue. METHODS: In the present study, we performed immunohistochemistry for traditional germinal center markers and for Smad1 in human reactive lymphoid and follicular lymphoma tissues to investigate Smad1's usefulness in the diagnosis of follicular lymphoma. RESULTS: In the reactive germinal centers, most cells were positive for Smad1. Among the 27 follicular lymphoma cases, 17 of 21 (80%) were Smad1 positive, 17 of 27 (63%) were positive for CD10, and 23 of 27 (85%) were positive for Bcl6. Notably, three cases expressed CD10 only, and one only expressed Bcl6. All these cases were grade 3 tumors and showed follicular and diffuse growth patterns. CONCLUSIONS: These results indicate that Smad1 is a candidate as a germinal center marker. Furthermore, they suggest that the Smad signaling pathway might be involved in follicular lymphoma.
Diagnosis ; Germinal Center ; Humans ; Immunohistochemistry ; Lymphoid Tissue ; Lymphoma ; Lymphoma, Follicular* ; Sensitivity and Specificity ; Smad Proteins

The carcinoid tumors of middle ear are very rare, however, more than 50 cases including 2 cases in Korea have been reported since 1980. A 36-year-old male had been managed under the diagnostic impression of hemotympanum due to head trauma in 2005; he revisited our clinic after 8 years with sudden facial paralysis and external auditory canal mass. Canal wall down mastoidectomy and tympanoplasty were performed and pathologic results revealed a carcinoid tumor of the middle ear. A facial paralysis of this patient was cured after the treatment.
Adult ; Carcinoid Tumor* ; Craniocerebral Trauma ; Ear Canal ; Ear, Middle* ; Facial Paralysis* ; Humans ; Korea ; Male ; Tympanoplasty

The present lesion was the first reported case of a benign intracystic phyllodes tumor in the inguinal region. We report the case of a 51-year-old female patient who presented with an inguinal mass. A clinical diagnosis of malignant lymphoma was considered in this case. The resected tumor was well-circumscribed and showed numerous papillary nodular protrusions into a central cystic cavity (3.5x2.5 cm). The microscopic findings showed hyperplastic epithelium-lined cysts with leaf-like intraluminal epithelium-lined bland stromal projections. The epithelial cell linings were strongly positive for estrogen and progesterone receptors.
Diagnosis ; Epithelial Cells ; Estrogens ; Female ; Groin ; Humans ; Lymphoma ; Middle Aged ; Phyllodes Tumor* ; Receptors, Progesterone