Small round cell tumors (SRCTs) are a heterogeneous group of neoplasms composed of small, primitive, and undifferentiated cells sharing similar histology under light microscopy. SRCTs include Ewing sarcoma/peripheral neuroectodermal tumor family tumors, neuroblastoma, desmoplastic SRCT, rhabdomyosarcoma, poorly differentiated round cell synovial sarcoma, mesenchymal chondrosarcoma, small cell osteosarcoma, small cell malignant peripheral nerve sheath tumor, and small cell schwannoma. Non-Hodgkin\'s malignant lymphoma, myeloid sarcoma, malignant melanoma, and gastrointestinal stromal tumor may also present as SRCT. The current shift towards immunohistochemistry and cytogenetic molecular techniques for SRCT may be inappropriate because of antigenic overlapping or inconclusive molecular results due to the lack of differentiation of primitive cells and unavailable genetic service or limited moleculocytogenetic experience. Although usage has declined, electron microscopy (EM) remains very useful and shows salient features for the diagnosis of SRCTs. Although EM is not always required, it provides reliability and validity in the diagnosis of SRCT. Here, the ultrastructural characteristics of SRCTs are reviewed and we suggest that EM would be utilized as one of the reliable modalities for the diagnosis of undifferentiated and poorly differentiated SRCTs.
Chondrosarcoma, Mesenchymal ; Cytogenetics ; Diagnosis ; Gastrointestinal Stromal Tumors ; Genetic Services ; Humans ; Immunohistochemistry ; Lymphoma ; Melanoma ; Microscopy ; Microscopy, Electron ; Microscopy, Electron, Transmission* ; Neurilemmoma ; Neuroblastoma ; Neuroectodermal Tumors ; Osteosarcoma ; Pathology ; Peripheral Nerves ; Reproducibility of Results ; Rhabdomyosarcoma ; Sarcoma, Myeloid ; Sarcoma, Synovial

BACKGROUND: Pulmonary vessel sarcomas are rare, and their pathogenesis is still unclear. METHODS: We focus on the pathologic findings of fourteen pulmonary artery and/or vein sarcomas along with clinical prognosis. RESULTS: Nine patients were male and five were female, and they ranged in age from 26 to 72 years (mean, 47 years). There were ten cases of pulmonary artery sarcoma, three cases of pulmonary artery and vein sarcoma, and one case of pure pulmonary vein sarcoma. Ten out of the fourteen cases were associated with pulmonary thromboembolism. Microscopically, all the tumors showed an undifferentiated sarcomatous portion. There were leiomyosarcoma portions in 8 cases, malignant fibrous histiocytomatous portions in 7 cases, angiosarcomatous differentiation in 3 cases, and osteosarcomatous portion in 1 case. All but two patients died during the follow up period (range, 1 to 78 months). The mean survival time of the patients who died was 14 months and the longest survival time was 78 months after surgical resection. CONCLUSIONS: The current study is one of the largest single institutional reviews of pulmonary artery and/or vein sarcoma. Regardless of the histological components and macroscopic growth patterns, these rare tumors have a grave prognosis.
Female ; Follow-Up Studies ; Glycosaminoglycans ; Humans ; Leiomyosarcoma ; Male ; Prognosis ; Pulmonary Artery ; Pulmonary Embolism ; Pulmonary Veins ; Sarcoma ; Survival Rate ; Veins

Myoepithelioma is a rare benign tumor of salivary gland myoepithelial cells, most commonly as a spindle subtype. Here, we present two cases of fine needle aspiration cytology of plasmacytoid myoepithelioma arising from a parotid gland and a hard palate. Aspirates showed plasmacytoid cells with pink-staining, homogeneous, abundant eosinophilic cytoplasm eccentrically displacing the nucleus in cohesive and dissociated forms. Rarely, nuclear grooves and intranuclear cytoplasmic inclusions were evident. These unfamiliar cytologic findings of uncommon myoepithelioma often cause diagnostic difficulties in preoperative aspiration cytology. Recognition of those rare findings provides a reliable diagnostic clue.
Biopsy, Fine-Needle ; Cytoplasm ; Eosinophils ; Inclusion Bodies ; Myoepithelioma ; Palate, Hard ; Parotid Gland ; Salivary Gland Neoplasms ; Salivary Glands

Eosinophilic fasciitis is a scleroderma-like disease and it may present with paraneoplastic syndrome or as an isolated form of the disease. We report here on a case of eosinophilic fasciitis in a 20-year-old woman who presented with an abrupt onset of subcutaneous limb swelling and peripheral eosinophilia. Pathologically, the specimen was characterized by acute inflammation and thickening of the collagen bundles in the reticular dermis and superficial muscle fascia in addition to the overlying intraepidermal blisters that contained many eosinophils. Eosinophils, some lymphocytes and plasma cells were infiltrated in the superficial muscle fascia and subcutaneous fat. The diagnosis of eosinophilic fasciitis was confirmed by biopsy. It is intriguing that eosinophilic fasciitis showed the microscopic findings of intraepidermal blister with predominant inflammation, and the patient showed a good response to steroid therapy.
Biopsy ; Blister ; Collagen ; Dermis ; Eosinophilia ; Eosinophils ; Extremities ; Fascia ; Fasciitis ; Female ; Humans ; Inflammation ; Lymphocytes ; Muscles ; Panniculitis ; Paraneoplastic Syndromes ; Plasma Cells ; Subcutaneous Fat ; Young Adult

Herein, we report a case of micronodular thymoma with lymphoid stroma in a previously healthy 73-year-old male. Thymectomy was performed. The solid and macrocystic masses were encapsulated with focal invasion. The solid portion consisted of nodules of bland-looking spindle or round epithelial cells in lymphoid stroma containing prominent germinal centers. The epithelial cells had moderate amount of cytoplasm and occasional mucin production. The cystic portion was lined with cuboidal epithelium. According to World Health Organization (WHO) classification, the mass was diagnosed as a micronodular thymoma with lymphoid stroma accompanied by a pre-existing multilocular thymic cyst. Micronodular thymoma with lymphoid stroma, a possible variant of type A thymoma, is an extremely rare tumor. This so-called "unusual" variant may imply the schematic weakness of the current WHO classification that cannot cover all morphologic types. Further study is recommended for clarification of this variant and its incorporation into the current classification.
Cytoplasm ; Epithelial Cells ; Epithelium ; Germinal Center ; Humans ; Lymphoid Tissue ; Male ; Mediastinal Cyst ; Mucins ; Thymectomy ; Thymoma ; World Health Organization

Central core disease is a rare congenital myopathy characterized by the formation of cores that consist of abnormal arrangement of myofibrils inside the myofibers. We report a 5-year-old Korean girl who showed a fairly typical clinical course of non-progressive muscle weakness. Electrodiagnostic studies showed low-amplitude polyphasic electromyograph and normal nerve conduction velocity. Gastrocnemius muscle biopsy showed central cores in over 80% of the fibers on H&E section. Histochemistry revealed deficient or absent mitochondrial enzyme in the cores and type I predominance. Ultrastructurally both structured and non-structured cores were found separately or simultaneously in one fiber. This case is the first report in the Korean literature.
Child, Preschool ; Female ; Humans ; Microscopy, Electron ; Muscles/pathology/ultrastructure ; Muscular Diseases/*congenital/*pathology

PURPOSE: To report a case of a patient with cytomegalovirus (CMV) retinitis who was treated with oral valganciclovir. CASE SUMMARY: A 34-year-old man who had undergone anti-cancer chemotherapy for Non-Hodgkin lymphoma was referred to the ophthalmologic oncology clinic because of decreased vision in both eyes. Fundus examination showed white, opaque, and granular retinal lesions in both eyes, and a serologic test showed a positive response to CMV antibody IgG and a negative response to CMV antibody IgM. The patient received induction therapy with intravenous ganciclovir and maintenance therapy with oral valganciclovir 900 mg once daily. CMV retinitis reactivated 4 weeks after maintenance therapy was discontinued. At that point, the patient received induction therapy with oral valganciclovir 900 mg twice daily for 3 weeks and maintenance therapy with 900 mg once daily for 5 weeks. The retinal lesion disappeared and did not recur after oral administration of valganciclovir. The patient discontinued valganciclovir after 5 weeks of maintenance therapy, and CMV retinitis did not reactivate during 6 months of follow-up. CONCLUSIONS: Oral valganciclovir was clinically effective in the treatment of CMV retinitis in a patient who was treated with anti-cancer chemotherapy for non-Hodgkin lymphoma.
Administration, Oral ; Adult ; Cytomegalovirus ; Cytomegalovirus Retinitis ; Eye ; Follow-Up Studies ; Ganciclovir ; Humans ; Immunoglobulin G ; Immunoglobulin M ; Lymphoma, Non-Hodgkin ; Retinaldehyde ; Retinitis ; Serologic Tests ; Vision, Ocular

PURPOSE: The expressions of Cytokeratin7 (CK7) and CK20 have been studied by a lot of cancer researchers, and these 2 protein markers are often used to find the primary foci of metastatic cancers. There have been numerous studies on vimentin, p53 and Ki-67 as prognostic factors for different cancers. However, it seems that there are a few investigations on the expression of CK7 and CK20 in papillary carcinoma of the thyroid. This study aimed to investigate the expressions of CK7, CK20, vimentin, p53 and Ki-67 in papillary thyroid carcinoma, and we wanted to determine whether the expressions of vimentin, p53, and Ki-67 are related to such prognostic factors as age, the tumor size, nodal metastasis or perithyroidal tissue invasion. METHODS: Paraffin slices of 44 papillary thyroid carcinomas from 44 patients were used for immunohistochemistry with using monoclonal antibody against CK7, CK20, vimentin, p53 and Ki-67. The expressions of CK7, CK20 and vimentin were determined simply by the staining competence, and more than 5% positive cells out of 1,000 cells in a highpowered microscopic view was considered as positive for the p53 and Ki-67 expressions. The expressions of vimentin, p53 and Ki-67 were investigated for their correlation with age, perithyroidal tissue invasion, the size of the tumor and metastasis to the cervical lymph nodes. RESULTS: Total of 44 patients (7 men and 37 women) were examined. The average size of tumor was 1.3 cm, and 28 (63.6%) out of 44 patients had perithyroidal tissue invasion. 29 (65.9%) patients had cervical lymph node metastases. The expression of CK7 was observed in all 44 (100%) patients, but only three (6.8%) among them had the expression of CK20. The expression of vimentin was shown in 43 (97.7%) patients. The expressions of p53 and Ki-67 were seen in 33 (75%) patients and 12 (27.7%) patients, respectively. The expressions of vimentin, p53 and Ki-67 were not significantly related with age (P=1.0, 0.084), perithyroidal tissue invasion (P=1.0, 0.798), the size of the tumor (P=0.234, 0.313) and cervical lymph node metastases (P=0.582, 0.948). CONCLUSION: As expected, papillary thyroid carcinoma showed a CK7(+)/CK20(-) pattern. Further research is needed to find the meaning of the expression of vimentin because it was meaningless analyzing the relationship between the prognostic factors due to fact that 97.7% of the patients had the expression of vimentin. There was no statistically significant relation between the expressions of p53 and Ki-67 and age, the size of thyroid tumor, perithyroidal tissue invasionand cervical lymph node metastasis.
Carcinoma, Papillary ; Humans ; Immunohistochemistry ; Lymph Nodes ; Male ; Mental Competency ; Neoplasm Metastasis ; Paraffin ; Thyroid Gland* ; Thyroid Neoplasms* ; Vimentin*

Duplication cysts are rare congenital malformations, that may be detected anywhere along the alimentary tract, and they may communicate with the intestinal tract. Cystic duplication of the cecum is especially rare. About 80% of these cases are detected in the first 2 years of life as a result of an acute intestinal obstruction, which manifests as vomiting, recurrent abdominal pain, recurrent gastrointestinal bleeding and constipation. We report a case of intestinal obstruction secondary to a duplication cyst of the cecum in a neonate. The patient underwent surgery and was diagnosed subsequently, and is presently healthy.
Abdominal Pain ; Cecum ; Constipation ; Hemorrhage ; Humans ; Infant, Newborn ; Intestinal Obstruction ; Vomiting

A 37-year-old female presented with a conjunctival mass discovered 3 years prior. An excisional biopsy revealed a patternless proliferation of round and spindle-shaped cells with an eosinophilic fibrillary cytoplasm and vesicular nuclei with occasional inclusions. Psammoma bodies were arranged around the dilated irregularly-shaped vessels. Differential diagnoses included conjunctival solitary fibrous tumor (SFT), nevus, glomangioma, ectopic meningioma, and mesectodermal leiomyoma. The tumor cells were immunoreactive for CD34, CD99, bcl-2 and vimentin, and were negative for smooth muscle actin, desmin, glial fibrillary acidic protein, S-100 protein, epithelial membrane antigen, and human melanoma black-45. Ultrastructurally, the tumor cells had rough endoplasmic reticulum, free ribosomes, and scattered mitochondria without basal lamina or cellular junctions, which are features of fibroblasts. A diagnosis of SFT was rendered based on the light microscopic, immunohistochemical, and electron microscopic findings. We report here on the second case of a SFT arising in the conjunctiva, which clinically and histologically mimics conjunctival nevus, glomangioma, ectopic meningioma, and a hybrid neurogenic-myogenic tumor such as mesectodermal leiomyoma.
Actins ; Adult ; Antigens, CD34 ; Basement Membrane ; Biopsy ; Chimera ; Conjunctiva ; Cytoplasm ; Desmin ; Diagnosis, Differential ; Electrons ; Endoplasmic Reticulum, Rough ; Eosinophils ; Female ; Fibroblasts ; Glial Fibrillary Acidic Protein ; Glomus Tumor ; Humans ; Leiomyoma ; Light ; Melanoma ; Meningioma ; Mitochondria ; Mucin-1 ; Muscle, Smooth ; Nevus ; Ribosomes ; S100 Proteins ; Solitary Fibrous Tumors ; Vimentin