Peripheral primitive neuroectodermal tumor (pPNET), a rare, highly aggressive neoplasm of indetermined histogenesis, occurs typically in the soft tissues of the chest wall and the paraspinal region. Comprehensive diagnostic studies including histological, ultrastructural, immunohistochemical and molecular analyses have been stressed to diagnose this entity. We report a case of primary renal PNET which was incidentally found in a 59-year-old man who presented with generalized weakness for 4 months. He was diagnosed as a non-insulin dependent diabetes mellitus 15 years ago and has been made well by oral therapy. An ill-defined mass, measuring 3.5 3 cm, located in the left kidney and perirenal fat, was incidentally found by ultrasonogram during a renal diabetic examination. The mass was resected because of the unresponsiveness against one-year chemotherapy and radiation therapy. Grossly, a homogeneously solid, gray-white mass, measuring 2.8 1.8 cm, was noted in the mid portion of renal cortex. The mass showed severe adhesion to the perirenal fatty tissue. Microscopically, tumor cells were rather uniform, small round with scanty cytoplasm and often showed rosette formation. Ultrastructurally, they showed membrane-bound dense core granules, measuring 125~150 nm, intercellular junctions and microvillous cytoplasmic projections. The tumor cells were uniformly immunoreactive for neuron-specific enolase and were focally immunoreactive for CD99 (013), chromogranin, synaptophysin and cytokeratin. They were not reactive for S-100 protein, vimentin, Leu-7, leukocyte common antigen, desmin and smooth muscle actin. To our knowledge, this is the smallest renal PNET in literature.
Actins ; Adipose Tissue ; Antigens, CD45 ; Cytoplasm ; Desmin ; Diabetes Mellitus ; Drug Therapy ; Humans ; Intercellular Junctions ; Keratins ; Kidney* ; Middle Aged ; Muscle, Smooth ; Neuroectodermal Tumors, Primitive* ; Phosphopyruvate Hydratase ; Rosette Formation ; S100 Proteins ; Sarcoma, Ewing ; Synaptophysin ; Thoracic Wall ; Ultrasonography ; Vimentin

Pheochromocytomas are neuroendocrine tumors of chromaffin cell that originate in the paraganglia of the adrenal medulla. Approximately 10% of pheochromocytomas are found in the extra-adrenal paraganglia and are called paragangliomas. However, cases of middle mediastinal paragangliomas are very rare. In this case, the patient presented with a voice change and a headache. A middle mediastinal soft tissue mass with marked enhancement was detected on computed tomography of the chest. The 24-hour urine catecholamine level was markedly elevated. The middle mediastinal mass was biopsied via mediastinoscopy and the resulting immunohistochemical staining was compatible with a diagnosis of middle mediastinal paraganglioma. The mass was resected surgically and the symptoms were relieved.
Adrenal Medulla ; Chromaffin Cells ; Headache ; Humans ; Mediastinoscopy ; Mediastinum ; Neuroendocrine Tumors ; Paraganglioma ; Pheochromocytoma ; Thorax ; Voice

Purpose: Prognostic Index for Natural Killer Lymphoma (PINK) is the most widely accepted prognostic model for patients withextranodal natural killer/T-cell lymphoma (ENKTL) treated with non-anthracycline–based therapy. We aimed to evaluate the prognostic implications of serum β-2 microglobulin (β2M) in the context of PINK and proposed a new prognostic model. Materials and Methods: A total of 138 patients who were newly diagnosed with ENKTL and treated with non-anthracycline-based chemotherapy were identified. The cut-off value of high serum β2M was calculated by maximal-chi square methods (4.1 mg/L). A new prognostic model incorporating serum β2M into PINK was proposed and validated in an independent validation cohort (n=88). Results: The patients’ median age was 53.5 years (range, 19 to 80 years). Patients with high serum β2M levels had significantly worse overall survival (OS) and progression-free survival (PFS). In multivariate analysis, high serum β2M was an independent adverse prognostic factor for OS. A new PINK-B (Prognostic Index for Natural Killer Lymphoma-serum β-2 microglobulin) model stratifiedpatients into three groups with distinct OS and PFS in the training cohort (3-year OS, 84.1% [95% confidence interval, 75.1 to 94.2], 46.8% [36.1 to 60.8] and 17.6% [6.3 to 49.2] for the low-, intermediate, and high-risk groups, respectively; 3-year PFS, 70.6% [59.4 to 83.8], 35.9% [25.9 to 49.8], and 7.35% [1.1 to 46.7] for the low-, intermediate-, and high-risk groups, respectively). The PINK-B model was further validated in an independent cohort. Conclusion Serum β2M is an independent prognostic factor for ENKTL patients. The new serum β2M-based prognostic model may be useful for identifying ultra-high-risk patients, and it can easily be adopted into daily clinical practice.

BACKGROUND: The Hematopathology Study Group of the Korean Society of Pathologists conducted a nation-wide retrospective analysis of Korean pediatric lymphoma, to provide pathologic data on pediatric/adolescent lymphoma subtypes and features. METHODS: All lymphoma cases of all age groups were collected during a recent 2 year-period (2005-2006) from 32 institutes in Korea. Among 3,686 lymphoma patients, 142 who were age 18 or less were classified according to the World Health Organization (WHO) classification. RESULTS: Among 142 pediatric/adolescent lymphoma patients, Hodgkin lymphoma accounted for 21 (14.8%) and non-Hodgkin lymphoma (NHL) for 121 (85.2%). Hodgkin lymphoma appears to be more common in the pediatric/adolescent age group than in the all-ages group (14.8% vs 4.4%). T- and natural killer cell-NHL was more common in the pediatric/adolescent age group than in the all ages group (46.3% vs 22%). The majority of Korean pediatric/adolescent NHL cases was composed of Burkitt lymphoma, T- or B-lymphoblastic lymphoma, anaplastic large-cell lymphoma, and diffuse large B-cell lymphoma. For lymphoma patients under the age of 6 years, most had B-lymphoblastic or Burkitt lymphoma, which commonly presented at extranodal sites. CONCLUSIONS: The distribution of lymphoma subtypes in the pediatric/adolescent age group is quite different from the distribution of adults, but it was quite similar to distribution in Western countries.
Academies and Institutes ; Adult ; Burkitt Lymphoma ; Hodgkin Disease ; Humans ; Incidence ; Korea ; Lymphoma ; Lymphoma, B-Cell ; Lymphoma, Large-Cell, Anaplastic ; Lymphoma, Non-Hodgkin ; Retrospective Studies ; World Health Organization

BACKGROUND: The aim of study was to determine the relative frequency of malignant lymphoma according to World Health Organization (WHO) classification in Korea. METHODS: A total of 3,998 cases diagnosed at 31 institutes between 2005 and 2006 were enrolled. Information including age, gender, pathologic diagnosis, site of involvement and immunophenotypes were obtained. RESULTS: The relative frequency of non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL) was 95.4% and 4.6%, respectively. B-cell lymphomas accounted for 77.6% of all NHL, while T/natural killer (T/NK)-cell lymphomas accounted for 22.4%. The most frequent subtypes of NHL were diffuse large B-cell lymphoma (42.7%), extranodal marginal zone B-cell lymphoma (MZBCL) of mucosa-associated lymphoid tissue (19.0%), NK/T-cell lymphoma (6.3%) and peripheral T-cell lymphoma (PTCL), unspecified (6.3%), in decreasing order. The relative frequency of HL was nodular sclerosis (47.4%), mixed cellularity (30.6%), and nodular lymphocyte predominant (12.1%) subtypes. Compared with a previous study in 1998, increase in gastric MZBCL and nodular sclerosis HL, and slight decrease of follicular lymphoma, PTCL, and NK/T-cell lymphoma were observed. CONCLUSIONS: Korea had lower rates of HL and follicular lymphoma, and higher rates of extranodal NHL, extranodal MZBCL, and NK/T-cell lymphoma of nasal type compared with Western countries. Changes in the relative frequency of lymphoma subtypes are likely ascribed to refined diagnostic criteria and a change in national health care policy.
Academies and Institutes ; Delivery of Health Care ; Hodgkin Disease ; Korea ; Lymphocytes ; Lymphoid Tissue ; Lymphoma ; Lymphoma, B-Cell ; Lymphoma, B-Cell, Marginal Zone ; Lymphoma, Follicular ; Lymphoma, Non-Hodgkin ; Lymphoma, T-Cell, Peripheral ; Sclerosis ; World Health Organization