The aim of this study was to characterize the morphology of a polycystic kidney which was found in 100% of the transgenic mice homozygous for inv mutation and to gain insight into the pathogenesis of inherited polycystic kidney disease during the pre- and postnatal periods. The fetal and postnatal kidneys from the homozygous and heterozygous transgenic mice were examined by the light, transmission and scanning electron microscopes, image analyzer, and an immunohistochemistry utilizing the antibodies specific for each segment of the renal tubules (Tetragonolobus purpureas, Arachis hypogaea, Tamm-Horsfall protein, AE1/AE3, EMA, vimentin, Phaseolus vulgaris) was performed to determine the site of origin of renal cysts. Two developmental phases of a cystic disease were identified. The first phase, seen in fetal kidneys, was characterized by dilatation mainly of the proximal tubules and a few distal tubules. The later phase, in postnatal period, was characterized by progressive enlargement of the kidneys due to mainly cystic change of the collecting ducts, which distorted the normal architecture of both cortex and medulla and almost completely replaced the renal parenchyma. The cystic dilatation involved all segments of the nephron and the collecting duct as well as the Bowman's spaces of glomeruli. The epithelial cell hyperplasia was found as a micropolyp formation within the renal cysts and an increase in PCNA positive cells. These findings suggest that a cyst is not simply a ballooning of a renal tubule and the stretching of cells, formerly thought to be due to an altered compliance of an abnormal basement membrane, but indeed the result of increased numbers of tubular epithelial cells.
Animals ; Antibodies ; Arachis ; Basement Membrane ; Compliance ; Dilatation ; Epithelial Cells ; Hyperplasia ; Immunohistochemistry ; Kidney ; Mice ; Mice, Transgenic* ; Microscopy, Electron ; Nephrons ; Phaseolus ; Polycystic Kidney Diseases* ; Proliferating Cell Nuclear Antigen ; Uromodulin ; Vimentin

We herein describe a case of a 55-year-old healthy woman with localized primary thymic amyloidosis presented as a mediastinal mass, found incidentally by chest radiography. Computed tomography revealed a 4.1 cm soft tissue lesion with nodular calcification in the left anterior mediastinum. The resected specimen was a well-defined lobulating mass with calcification. Microscopically, the mass was consisted of amorphous eosinophilc hyalinized substances involving the thymus and intrathymic lymph nodes. These eosinophilic substances showed apple-green bi-refringence under polarized light after staining with Congo red. In immunohistochemical study, they were positive for kappa and lambda light chains and negative for amyloid A. There was no evidence of systemic amyloidosis in clinical investigations. A final diagnosis of localized primary thymic amyloidosis was made.
Amyloid ; Amyloidosis ; Congo Red ; Eosinophils ; Female ; Humans ; Hyalin ; Light ; Lymph Nodes ; Mediastinum ; Middle Aged ; Thorax ; Thymoma ; Thymus Gland

Rhinoscleroma is a chronic, granulomatous infectious lesion most frequently affecting the respiratory tract mucosa. This disease is endemic to Africa, Central and South America, South Central and Eastern Europe, the Middle East, and China. We report an extremely rare disease of nasal rhinoscleroma in Korea. The patient was a 63-yr-old man, who suffered from chronic nasal obstruction and septal deviation. Characteristic histology from a nasal biopsy was proven and special stains for bacteria were employed: periodic acid-Schiff, Warthin-Starry silver, Giemsa, and Gram stains. Isolation of Klebsiella rhinoscleromatis from a culture of nasal discharge was failed, but ultrastructural examination of numerous phagocyzed bacilli in the Mikulicz cells confirmed the diagnosis. The histiocytic nature of the Mikulicz cells was confirmed, using CD 68 and alpha-1 antitrypsin, and by the ultrastructural features of Mikulicz cells. Here, we emphasize the recognition of this rare entity in nonendemic regions, frequently leading to delayed diagnosis.
Endemic Diseases ; Fibrosis ; Human ; Klebsiella pneumoniae/*isolation & purification ; Korea ; Male ; Microscopy, Electron ; Middle Aged ; Nasal Mucosa/*microbiology/pathology/ultrastructure ; Rhinoscleroma/*pathology

We treated a case of extramammary Paget's disease that affected the scalp of a 45-year-old female. It is extremely rare that the disease arises in areas other than the anogenital region and the axillae. The lesion was a round erythematous oozing crusted hairless patch. Histopathologically, many pagetoid cells were found within the epidermis and dermis. The cytoplasms of these cells stained with alcian blue at pH 2.5, CEA, EMA and low-molecular-weight-cytokeratin. The patient underwent a wide local excision. We used a mapping technique to reveal the distribution of microscopically involved lesions.
Alcian Blue ; Axilla ; Cytoplasm ; Dermis ; Epidermis ; Female ; Humans ; Hydrogen-Ion Concentration ; Middle Aged ; Paget Disease, Extramammary* ; Scalp*

BACKGROUND: There is a long-standing controversy whether melanocytes in vitiligo of more than 1 year duration are actually lost or still present. Resolving this matter is essential in understanding the underlying pathology and for the development of the treatment. On previous immunohistochemical and ultrastructural studies of vitiligo lesions, damage of melanocyte and keratinocyte in early lesions were reported and complete absence of melanocyte in long standing lesions were known. OBJECTIVE: This study aimed to determine the existence of the differences in pathologic changes in melanocytes according to the duration of the lesion. METHODS: We investigated the vitiliginous skin samples from 31 patients with early(less than 1 year duration) vitiligo and 30 patients with long standing(l to 5 years duration) vitiligo under the electron microscopy. RESULTS: Multiple degenerative changes in melanocytes were observed in the early and long standing lesions. In long standing lesions, degeneration of melanocytes including pyknotic, in-dented nuclei, vacuolated cytoplasms and blunted dendrites were more pronounced than early lesions. Even in long standing lesions, definite or presumptive melanocytes were observed in 16(53.3%) of 30 cases. CONCLUSION: Our results suggest that the melanocytes of vitiligo lesions were damaged and that the percentage of degenerative changes increase in accordance with the duration of the lesion. However, in long standing lesions as well as in early lesions, some residual melanocytes can be observed ultrastructurally.
Cytoplasm ; Dendrites ; Humans ; Keratinocytes ; Melanocytes ; Microscopy, Electron ; Pathology ; Skin ; Vitiligo*

Pulmonary cystic and cavitary lesions caused by diverse etiologies are commonly encountered in chest imaging. The terms "cyst" and "cavity" are used to describe air-filled regions in the center of a nodule or consolidation of the lung. To date, only radiologic aspects of these lesions have been addressed. The morphologies of pulmonary cystic and cavitary lesions exhibit a broad spectrum, ranging from benign to malignant pulmonary diseases of acquired or congenital origin, including variable infectious diseases. In this review, we summarized the differential diagnosis of pathological entities to provide pathologists and radiologists with an overview of the diseases most commonly associated with pulmonary cystic and cavitary lesions in adults and children. The results showed slightly different patterns in the distribution of the diseases in the two groups. The most common causes of cavitary lesions include malignancy and infection in adults, and congenital malformation in children. Therefore, identification of pathologic entities correlating with the radiologic findings, clinical course, and location of the lesion is important in the evaluation of cystic and cavitary lung lesions in order to avoid unnecessary surgical procedures or delayed treatment.
Adult ; Child ; Communicable Diseases ; Diagnosis, Differential ; Humans ; Lung ; Lung Diseases ; Thorax

Diffuse pulmonary meningotheliomatosis (DPM) is an extremely rare condition. We herein report a unique case of DPM in a 54-year-old woman with a previous history of hepatocellular carcinoma. A chest computed tomography showed diffuse bilateral nodular infiltration, suggesting miliary spread of metastatic hepatocellular carcinoma. The patient underwent a video-assisted thoracoscopic surgery for diagnostic purposes. The cut surface of the lung specimen showed multiple dispersed small nodules, consisting of variably sized nests or whorls of bland epithelioid cells often along the walls of alveolar septa or in a perivascular network within the alveolar interstitium. The tumor cells showed immunoreactivity for epithelial membrane antigen, vimentin, and progesterone receptor. DPM should be included in the differential diagnosis of diffuse multiple small nodules or a reticular pattern in the radiologic studies.
Carcinoma, Hepatocellular ; Diagnosis, Differential ; Epithelioid Cells ; Female ; Humans ; Lung ; Lung Neoplasms ; Meningioma ; Middle Aged ; Mucin-1 ; Receptors, Progesterone ; Thoracic Surgery, Video-Assisted ; Thorax ; Vimentin

Scrotal leiomyomas with atypical bizarre nuclei are rare, which might be misdiagnosed as malignant tumor. We describe a case of scrotal bizarre leiomyoma in a 65-yr-old man. The tumor was a 1 cm-sized, well circumscribed, oval mass arising from the tunica dartos muscle. Histologically, it was formed by whorling bundles of fusiform cells with occasional atypical, pleomorphic nuclei and pseudoinclusions. Mitosis was not found. Although morphologically atypical, scrotal bizarre leiomyomas take on a biologic behavior not different from that of conventional leiomyoma, they should be distinguished from leiomyosarcoma to avoid unnecessary treatment.
Aged ; Genital Neoplasms, Male/*pathology/surgery ; Human ; Leiomyoma/*pathology/surgery ; Male ; Scrotum/*pathology

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

Micronodular thymoma with lymphoid stroma (MNT) is an extremely rare tumor and has not been reported in Korea. Herein, we report a case of MNT diagnosed in a 75 year-old male. The mass was incidentally identified on thoracic computer tomography (CT) during work-up for a cardiac mass. The resected thymic mass was ovoid and solid measuring 3.5x3 cm in size and showed homogenously white tan, solid and firm cut surface. Microscopically, the tumor had a thin fibrous capsule except small foci of invasion to thymic adipose tissue, and consisted of characteristic multiple discrete epithelial nodules in abundant lymphoid stroma. The epithelial nests anastomosed each other, forming a vague cord-like structure. The cells in the epithelial nests were bland, spindle to oval shape with relatively abundant cytoplasm, slightly vesicular chromatin and one definite nucleolus. The lymphoid stroma contained prominent germinal centers. No evidence of recurrence or metastasis has been found within 4 years of surgery.
Adipose Tissue ; Chromatin ; Cytoplasm ; Germinal Center ; Humans ; Korea ; Male ; Neoplasm Metastasis ; Recurrence ; Thymoma ; Triacetoneamine-N-Oxyl