Multiple Microvenular Hemangioma Clinicopathologically Mimicking Early Stage Kaposi Sarcoma: A Case Report / 대한피부과학회지

Microvenular hemangioma (MVH) is a rare acquired benign vascular neoplasm, which presents commonly as a solitary purple-to-red nodule or plaque measuring approximately 10 mm in diameter. MVH occurs primarily on the extremities or the trunk. Most lesions are solitary, and multiple lesions are rare. Histopathological features of MVH include numerous, scattered, thin and irregularly branching small vessels in the dermis and endothelial cells without atypia. Owing to similarities in clinical morphology and histopathological features, MVH may often be indistinguishable from the early patch stage of Kaposi sarcoma. Immunohistochemical (IHC) analysis helps differentiate between the 2 diseases. The results of IHC tests in patients with MVH show positive staining for CD31 and smooth muscle actin and typically, negative staining for the human herpes virus 8 antigen. We report a rare case of multiple MVH clinically mimicking the early patch stage of Kaposi sarcoma in a 63-year-old woman who presented with a 3-year history of slowly growing, compressible, soft, bluish-purple macules and plaques on the trunk and right arm.

In vivo Cell CFSE Fluorescence Negative Staining for Detection of Super Paramagnetic Iron Oxide Nanoparticles Phagocytosed by Mouse Mononuclear Macrophage Leukemia Cells-RAW264.7 / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the feasibility and fluorescence characteristics of CFSE negative staining for in vivo cell imaging of super paramagnetic iron oxide nanoparticles (SPIO) phagocytosed by mouse mononuclear macrophage leukemia cells-RAW264.7.</p><p><b>METHODS</b>After labeled with SPIO, the RAW264.7 macrophages were stained with Prussian blue stain and CFSE fluorescence negative stain step by step. Furthermore, trypan blue staining was used to evaluate cell viability of cells which stained with CFSE. At last, laser scanning confocal microscope was used to measure SPIO in cells through CFSE fluorescence negative stain method.</p><p><b>RESULTS</b>SPIO within RAW264.7 macrophages showed blue in Prussian's blue staining, while showed negative area in CFSE negative staining. Good consistencies between Prussian's blue staining and CFSE negative staining were observed. In addition, RAW264.7 macrophages showed high viability after SPIO/CFSE dual-labeled method, proved by typan stain.</p><p><b>CONCLUSION</b>The CFSE fluorescence negative staining may be used for detecting SPIO that phagocytosed by RAW264.7 macrophages and it is showed good consistency that confirmed one another when compared to classic Prussian' blue staining.</p>

p27 Loss Is Associated with Poor Prognosis in Gastroenteropancreatic Neuroendocrine Tumors / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) represent a heterogeneous disease group originating from the neuroendocrine cells. Identification of prognostic markers, related to neuroendocrine tissue-selective tumorigenesis, is necessary to find therapeutic targets. MATERIALS AND METHODS: A total of 327 patients with GEP-NETs were included in this study; there were 49 gastric, 29 duodenal, 49 pancreatic, 12 hepatobiliary, 33 appendiceal, 5 proximal colon, and 150 distal colon cases. We performed immunostaining with the tissue microarray method for menin, p27, and p18. RESULTS: We observed negative staining for menin, p27, and p18 in 34%, 21%, and 56% of GEP-NETs, respectively. The loss of p27, but not menin, was positively correlated with the grade of Ki-67. Menin-/p27-, menin-/p27+, menin+/p27-, and menin+/p27+ phenotype groups included 13%, 22%, 8%, and 57% of patients, respectively. A dichotomized comparison showed that menin- or p27- tumors were significantly associated with foregut and midgut localizations, high World Health Organization (WHO) grade, lymph node metastasis, and more advanced stage as compared to menin+/p27+ patients. Kaplan-Meier analysis for the overall survival showed that p27 loss was significantly associated with decreased survival. Multivariate analysis showed that p27 loss is an independent factor for poor overall survival. CONCLUSION: Our results revealed that the loss of p27 is associated with poor prognosis and the menin-p27 pathway is important in the tumorigenesis of GEP-NETs.

Hepatoid carcinoma of the ovary without staining for alpha-fetoprotein

Primary hepatoid carcinoma of the ovary (HCO) is a rare type of ovarian tumor that resembles hepatocellular carcinoma both histologically and immunohistochemically in its staining for alpha-fetoprotein (AFP). We describe a 51-year-old woman who presented to our hospital complaining of abdominal pain. Computed tomography scan revealed a large tumor in the pelvis. She underwent total hysterectomy and bilateral salpingo-oophorectomy with tumorectomy. A right ovarian mass measuring 9x8x6 cm was found. Histological diagnosis was hepatoid carcinoma of the right ovary. But, immunohistochemically, tumor cells were not immunoreactive for AFP and there was no elevation of serum AFP level. This is the first report of an ovarian carcinoma with typical histologic features of HCO with negative staining for AFP and normal level of serum AFP in the world.

Detection of white spot syndrome virus in Brazil using negative staining, immunoelectron microscopy and immunocytochemistry techniques / Detección del virus del síndrome de mancha blanca en el Brasil utilizando inmunomicroscopía e inmunomarcación con partículas de oro coloidal

In this study thirty shrimp samples from commercial marine shrimp (L. vannamei) farms of southern region of Brazil were obtained. Hepatopancreas and shell scrapings fragments collected in these animals were processed by transmission electron microscopy using negative staining (rapid preparation), immunoelectron microscopy and immunocytochemistry (immunolabelling with colloidal gold particles) techniques. On the transmission electron microscopy a great number of white spot virus particles, ovoid or bacilliform-to-ellipsoid, measured 230-290 nm in length and 80-160 nm in diameter with intra-nuclear projections were visualized by the negative staining technique in 27 (90 percent) out of 30 samples examined. Using immunoelectron microscopy technique, the anti-VP 664 serum agllutinated a large number of particles formed by antigen-antibody interaction. In the immunocytochemistry technique, the antigen-antibody reaction was styrongly marked by the particles of colloidal gold over the virus. Notably, this is the first report, to our knowledge, describing use of these microscopy techniques to study Brazilian L. vannamei marine shrimp samples; moreover, this methodology also appears to be a viable complementary tool for diagnosing the presence of the white spot virus within shrimp tissues. Importantly, these are the first photoelectron micrographs of the WSSV in Brazil.

Se obtuvieron para el estudio 30 muestras de camarones marinos comerciales (L. vannamei) de las granjas de la región sur de Brasil. Fueron procesados fragmentos de hepatopáncreas y raspados internos del cefalotórax recogidos en estos animales por microscopía electrónica de transmisión con tinción negativa (preparación rápida), inmunomicroscopía y técnicas de inmunocitoquímica (inmunomarcación con partículas de oro coloidal). En la microscopía electrónica de transmisión de un gran número de partículas de virus de la mancha blanca, ovoide o elipsoidal a baciliformes, medían 230-290 nm de longitud y 80-160 nm de diámetro. En 27 (90 por ciento) de las 30 muestras examinadas intra-nuclear proyecciones se visualizaron mediante la técnica de tinción negativa. Utilizando una técnica de inmunomicroscopía electrónica, el anti-suero VP 664 reunió a un gran número de partículas formadas por la interacción antígeno-anticuerpo. En la técnica de inmunocitoquímica, la reacción antígeno-anticuerpo fue fuertemente reforzada por las partículas de oro coloidal en los virus. En particular, en Brasil este es el primer informe, a nuestro entender, que describe el uso de estas técnicas de microscopía en muestras de camarón marino L. vanamei. Además, esta metodología también parece ser una herramienta complementaria viable para diagnosticar la presencia del virus de la mancha blanca en tejidos de camarón. Es importante destacar que estas son las primeras fotos en microscopia electrónica del WSSV obtenidas en Brasil.

Clinicopathological Characteristics of Colorectal Cancer according to Gender Difference

BACKGROUND/AIMS: Colorectal cancer (CRC) has been one of the major causes of death and has become a major public health concern. The incidence of CRC has been increasing regardless of gender in Korea. Until now, however, the studies on gender-based clinicopathological characteristics of CRC focused on pathology have never been reported. Therefore, we aimed to evaluate the difference in clinicopathological characteristics of CRC according to gender in Korea. METHODS: Medical records of 342 patients with advanced CRC who underwent surgical resection at Kyung Hee University Hospital at Gangdong from June 2006 to December 2011 were retrospectively analyzed. The data of the clinicopathological characteristics of CRC by gender difference were compared. RESULTS: Of these 341 patients, 203 (60%) patients were male and 138 (40%) patients were female. The male preponderance was noted in all age groups for total CRC and left-sided CRC. However, for right-sided colon cancer, this male preponderance was significantly decreased with increasing age groups (P=0.025) and was finally reversed in elderly groups (age > or =60 years). The microsatellite instability represented by negative staining for hMLH1 and hMSH2 was more frequently detected in women than men (P=0.037). CONCLUSIONS: The male preponderance in right-sided colon cancer decreased with increasing age groups and finally reversed in age groups more than 60 years. Microsatellite instability with immunohistochemical staining was more frequently detected in women. However, further studies with a large number of patients are warranted on this issue.

Synchronous gynecologic malignancy and preliminary results of Lynch syndrome / 부인종양

OBJECTIVE: Lynch syndrome is a hereditary cancer syndrome that increases the risks of colorectal and gynecologic malignancies such as endometrial and ovarian cancer. Studies have shown that mutations in mismatch repair genes (MSH2, MSH6, and MLH1) are associated with Lynch syndrome. The aim of our study was to estimate the value of MSH2, MSH6, and MLH1 immunohistochemistry based on family history in a Korean sample. METHODS: Thirty six women with synchronous gynecologic tumors of endometrial and ovarian cancer were identified among patients being treated at our institution. Among them, 32 patients had tumor blocks (total 62 slides) available for analysis. According to a diagnostic algorithm, we performed immunohistochemistry analyses. Staining was scored based on intensity and proportion (negative or 0: intensity undetectable or minimal, proportion <5%; weak or 1+: intensity mild, proportion 5-30%; strong or 2+: intensity moderate to marked, proportion 30-99%). RESULTS: Among 32 eligible patients, 9 (28%) had a family history of cancer. Six patients (19%) were negative for MLH1; among them, four (4/6) were negative at both sites. Nine patients (28%) were negative for MSH2 or MSH6 at both sites or negative for both MSH2 and MSH6. Among these three patients showed negative staining for both sites. The three patients showing negative staining for MLH1, MSH2, and MSH6 at both sites with family history were considered to be the screening positive groups of Lynch syndrome. CONCLUSION: In this study, the frequency of Lynch syndrome associated immunohistochemical staining (MLH1, MSH2, and MSH6) group was estimated as 9% (3/32) among Korean women with synchronous gynecologic tumors.

Detection and characterization of human rotavirus in hospitalized patients in the cities of Ponta Grossa, Londrina and Assai - PR, Brazil

Acute diarrheal disease is still one of the major public health problems worldwide. Rotaviruses (RV) are the most important viral etiologic agents and children under five years of age are the target population. OBJECTIVE: To investigate the rate of RV infection in hospitalized patients due to acute diarrhea in the cities of Ponta Grossa, Londrina and Assai - Paraná. METHODS: Latex agglutination (LA); immunochromatography (ICG); polyacrylamide gel electrophoresis (PAGE) and negative staining electron microscopy (ME) tests were used to detect the virus. For the genotyping, RT-PCR and RT-PCR-ELISA were used, respectively, for NSP4 and VP4/VP7. RESULT: Out of 124 samples there were 69 positive stool samples for RV, for at least one of the used tests, 67 of them being RV group A (RV-A). Overall, most of the RV positive stool samples came from children under thirteen years of age. However, 12 positive cases occurred in patients aged 13 years or above, including an 81-year old patient. CONCLUSION: The data showed similar electropherotypes and genotypes G, P and NSP4 of the inland wild circulating strains of RV.

A Case of Superficial Acral Fibromyxoma / 대한피부과학회지

Superficial acral fibromyxoma (SAF) is an uncommon soft tissue tumor that has recently been showed to be a separate disease entity. It is most often located in the ungal region of the fingers and toes of middle-aged adults. It is histologically characterized by a slight to moderate cellular proliferation of spindle cells and stellate cells arranged in a random, storiform or fascicular pattern, within a myxoid, myxocollagenous or collagenous stroma with a prominent vasculature. The neoplastic cells show positive staining for CD34, CD99 and EMA, but negative staining for S100, HMB45, cytokeratin, smooth muscle actin (SMA) and desmin. We report here on a typical case of SAF that occurred on the left index finger of a 44-year-old man.

Ectopic Extramammary Paget's Disease of the Breast Skin: A Case Report / 한국유방암학회지

Whereas extramammary Paget's disease commonly occurs in the apocrine gland rich skin areas, ectopic extramammary Paget's disease develops in the skin areas that are devoid of apocrine glands. We experienced the case of a 34 year-old female patient who had a skin lesion in the upper outer quadrant of the right breast for 5 years and that lesion was diagnosed as Paget's disease according to the punch biopsy. There was no other underlying malignancy, and so wide excision was performed. The final pathologic diagnosis was Paget's disease confined to the epidermis and the size of the tumor was 3.0x1.1 cm. Positive staining for cytokeratin 7, epithelial membrane antigen and negative staining for S-100 protein and HMB-45 was observed on the immunohistochemical tests. We report here on an extremely unusual case of ectopic extramammary Paget's disease of the breast skin, and we include a review of the relevant literature.

Three Cases of Noninvoluting Congenital Hemangioma / 대한피부과학회지

Congenital hemangioma (CH), which is already fully formed at birth, is a rare clinical entity that is distinctly different from the common postnatally-occurring hemangioma of infancy (HOI). These two forms of CH have been described according to their clinical courses: apart from the clinical features of presentation at birth, there is the rapidly involuting congenital hemangioma (RICH) with rapid involution shortly after birth and the noninvoluting congenital hemangioma (NICH) with neither postnatal enlargement nor spontaneous involution. It is important to recognize this uncommon disease entity NICH in the early period because it has no tendency for spontaneous regression, so timely therapeutic intervention is needed, which is in contrast to that of HOI. We present 3 patients who were 1-, 3- and 13-year-old girls with red-stippled blue to blue gray vascular lesion. They all showed their lesions since birth and the lesions remained unchanged with no subjective symptoms. Doppler ultrasonography demonstrated a well-defined fast-flowed vascular lesion confined to the dermis and subcutis. The histology commonly showed lobular growth of capillaries, centrilobular irregular and often stellate vessels, extralobular large vessels and more conclusively, negative staining for GLUT-1, which is unlike HOI.

Primary Retroperitoneal Malignant Gastrointestinal Stromal Tumor Mimicking Adrenal Mass

Gastrointestinal stromal tumor (GIST) is the most common non-epithelial tumor in the gastrointestinal tract. Although GIST occurs mainly in the gastrointestinal tract, it also occurs, rarely, in non-gastrointestinal tract and in this case, it is often named as extra-gastrointestinal stromal tumor (EGIST). We experienced a 68-year-old male patient who had been diagnosed preoperatively with accidentaloma of the left adrenal gland by computed tomography, and finally diagnosed as primary retroperitoneal malignant GIST, postoperatively. The operation was performed via anterior abdominal approach, and complete surgical resection was done for a 7 cm sized retroperitoneal tumor near the left adrenal gland. Primary retroperitoneal malignant GIST was the final pathologic diagnosis and the size of the tumor was 6.5 cm and the mitotic count was 7 per high-power field. Diffuse strong positive staining for c-kit protein, CD34 and negative staining for desmin were observed in a immunohistochemistry test. We report here the unusual case of primary retroperitoneal malignant GIST mimicking adrenal mass.

A Case of Esophageal Benign Schwannoma Removed by Endoscopic Mucosal Resection / 대한소화기내시경학회지

Esophageal schwannoma is a very rare neoplasm. The differentiation of schwannoma from the other submucosal tumors such as GISTs or leiomyoma is very difficult to do on the preoperative examination with performing esophagoscopy and computed tomography. The diagnosis is generally not confirmed until the histologic and immunohistochemical tests of the tumor are performed. A 38- year-old man presented to us with neck discomfort. The endoscopy showed a middle esophageal submucosal tumor that measured 12 mm in size and there were no mucosal changes. The endoscopic ultrasonography showed a tumor in the muscluaris mucosa layer without lymphadenopathy. After band ligation of the lower part of the tumor, it was removed by performing endoscopic mucosal resection and using a snare. A definitive diagnosis of esophageal benign schwannoma was made from the pathologic findings, which included positive immunohistochemical staining for S-100 protein and negative staining for C-kit, CD34 and actin. We report here on an esophageal benign schwannoma that was removed by endoscopic mucosal resection.

Prognostication by Cluster Analysis of COX-2, MMP-9 and P53 Expression and?by Clinico-pathologic Correlation Analysis in Non-small Cell Lung Cancer / 결핵및호흡기질환

BACKGROUND: In pathogenesis and prognosis of lung cancer, significance of enormous types of genetic expression were very compounding and undetermined. We performed this study to search association between clinical characteristics and expression of COX-2, MMP-9 and p53 in non-small cell lung cancer. METHODS: Ninety-one patients with adenocarcinoma or squamous cell carcinoma were enrolled. We had searched clinical data retrospectively and performed immunohistochemical staining for COX-2, MMP-9 and p53. We had analyzed significance of these three genes in clinical features and prognosis for survival. RESULTS: 1) In squamous cell carcinoma, male was predominant and was significantly correlated with smoking. 2) Major prognostic determinants for overall survival were curative resection. 3) Expression of COX-2 was more frequent in adenocarcinoma than in squamous cell carcinoma. 4) Negative staining of COX-2, MMP-9 and p53 was more frequent in squamous cell carcinoma than adenocarcinoma. 5) Survival duration was longer in the group with positive expression of p53 and negative for COX-2 and MMP-9 (median duration of survival = 165.6 weeks) than groups with the other expressional patterns. 6) Significant correlation was found between expression of MMP-9 and COX-2. In squamous cell carcinoma, expression of MMP-9, COX-2 and mutant p53 were mutually correlated. 7) COX-2 expression was significant prognostic factor for survival in resected cancer group. In unresected inoperable non-small cell lung cancer group, MMP-9 was statistically significant prognostic factor for overall survival. CONCLUSION: COX-2 and MMP-9 might have some roles for progression or prognosis in some selected patients with non-small cell lung cancer. COX-2 and MMP-9 may have some roles for disease progression or prognosis in selected patients with NSCLC.

Colonic Schwannoma

Schwannoma is a common soft tissue tumor, but it appears to be rare among the spindle cell mesencymal tumors of the gastrointestinal tract. Gastrointestinal Schwannomas (GIS) are rare and most of them originate in the stomach or the small bowel. GIS of the colon is extremely rare. The most important issue to be addressed for this type of tumor is the difficulty in making the correct preoperative diagnosis. Less than 10% of cases have been diagnosed as schwannoma preoperatively. A 58-year-old man was found to have a 3.5cm sized submucosal transverse colon tumor on the preoperative colonoscopy, abdominal CT and MRI. Wedge resection was done and the submucosal mass was diagnosed as schwannoma on the immunochemical staining. The immunochemical results were negative staining for CD 117(KIT) and CD 34 and positive staining for S-100 protein, which is all consistent with schwannoma. We report here on the first case of colonic schwannoma in Korea, along with a review of the literature.

Increased expression of pAKT is associated with radiation resistance in cervical cancer / 부인종양

OBJECTIVE: The aim of this study was to investigate the association of phosphorylated AKT (pAKT) expression and radiation resistance in cervical cancer. METHODS: A retrospective review was made of the records of 25 women who received primary radiation therapy due to locally advanced cervical cancer (LACC) with FIGO stage IIB-IVA. Nine patients regarded as radiation resistant developed local recurrences with a median progression free interval of 10 months. Sixteen patients did not show local recurrences, and were regarded as a radiation sensitive group. Using pretreatment paraffin-embedded tissues, we evaluated pAKT expression by immunohistochemistry. RESULTS: A significant association was found between the level of pAKT expression and local recurrence. Immunohistochemical staining for pAKT was significantly more frequent in the radiation resistant than in the radiation sensitive group (p=0.007). The mean progression free survival (PFS) was 84 months for patients with pAKT negative staining (17 cases) and 44 months for patients with pAKT positive expression (8 cases)(p=0.015). CONCLUSION: These results suggest that signaling from PI3K/pAKT can lead to radiation resistance in LACC.

Cellular localization of MUC1 in Benign and Malignant Breast Lesions with the Histological Correlation and the Prognostic Significance / 한국유방암학회지

PURPOSE: MUC1 is a large transmembrane glycoprotein, which is overexpressed in the majority of carcinomas. The high expression of MUC1 is associated with aggressive tumors, with the MUC1 antigen used as a marker to monitor disease progression in breast cancer patients. Although the MUC1 tumor marker is both sensitive and specific for predicting a relapse in breast cancer, it is not commonly used during the follow-up of breast cancer patients. The aim of this study was to evaluate whether the differential patterns of MUC1 expression in different histological types of breast carcinoma could be used to distinguish tumors from benign lesions, and determine its prognostic relevance with other biological parameters. METHODS: 22 normal breast, 7 intraductal hyper-plasia (IDH) and 307 malignant lesions were selected and immunostained with MUC1. The patterns of reaction were classified as intraluminal border (ILB), cytoplasmic, intercellular membrane (ICM), intranuclear or mixed staining. RESULTS: All the normal breast samples showed weak cytoplasmic staining in the ducts and lobules. All the IDH samples showed moderate cytoplasmic and ILB staining. Of the 307 malignant lesions, only 2 (0.8%) showed negative staining; MUC1 positivity was observed in 4 (1.3%), with only ILB staining; 8 (2.6%) with weak cytoplasmic staining, 16 (5.2%) with weak cytoplasmic and intranuclear staining, 168 (54.7%) with moderate cytoplasmic and ILB staining, and 109 (35.5%) with strong cytoplasmic and ICM staining. MUC1 positivity with a moderate to strong staining intensity was observed in 90.6% of the infiltrating ductal carcinomas (221/244), 96.5% of the intraductal carcinomas (28/29), 87.5% of the infiltrating lobular carcinomas (7/8), 66.6% of the mucinous and secretory carcinomas (10/15), 100.0% of the apocrine carcinomas (5/5) and 100.0% of the medullary carcinomas (6/6). The expression of MUC1 was statistically significant between the histological tumor types (p = 0.034), tumor size (p = 0.046), and HER-2/neu (p = 0.004). CONCLUSION: These data suggest the expression of MUC1 was different in normal breast, IDH and malignant breast tumors, and was significantly correlated with the histological tumor types, tumor size and HER-2/neu oncogene.

Subconjunctival Juvenile Xanthogranuloma Involving the Limbus Associated with Neurofibromatosis

PURPOSE: To report a case of isolated subconjunctival juvenile xanthogranuloma invading the corneal limbus in a patient with neurofibromatosis. METHODS: A 2-year-old boy visited the hospital with a conjunctival yellow-brown, non-tender mass of the left eye, which had been found 2 months earlier. Anterior segment examination revealed a 9 x 7 mm-sized subconjunctival elevated mass with an ill-defined border, invading the supero-temporal limbus. Additional ophthalmic examinations did not show any abnormal findings. In the trunk and extremities, there were multiple soft nodules and brown macules. An excisional biopsy of the subconjunctival mass, histopathologic and immunohistochemical examinations were performed. RESULTS: The mass was adhered to the episcleral tissue, without scleral or conjunctival involvement. The histological examination showed a granulomatous lesion consisting of multiple lipid-laden macrophages and other inflammatory cells. The immunohistochemical study showed positive staining for CD68 and negative staining for S100 protein. The multiple soft nodules and brown macules in the trunk and extremities were identified as neurofibromas and caf -au-lait macules by a dermatologist, and the patient was diagnosed with neurofibromatosis. CONCLUSIONS: We report a rare case of subconjunctival juvenile xanthogranuloma involving the limbus, associated with neurofibromatosis.

A Case of Epithelioid Hemangioendothelioma / 대한피부과학회지

Epithelioid hemangioendothelioma is a rare tumor of vascular endothelium that is considered to be of borderline malignancy. Typical sites of involvement include soft tissue and less frequently, liver and lung. A 45-year-old woman had found a nodule on left second finger. There were no specific personal or family history. Physical examination revealed a 0.7x0.7cm sized skin-colored hard nodule on the dorsum of the distal interphalangeal joint of left second finger. There were no lymphadenopathy, hepatosplenomegaly, or bone tenderness. The patient underwent an excision of the lesion. On microscopic examination, a moderately well-circumscribed nodule composed of sheets and cords of epithelioid cells, many of which possessed intracytoplasmic lumina, was noted in the dermis. Erythrocytes were seen within some of the lumina. On immunohistochemical staining, the cells showed positive staining for factor VIII-related antigen and smooth muscle actin, and negative staining for CD31, CD34 and S-100.

Primitive Neuroectodermal Tumor of the Kidney / 대한비뇨기과학회지

Primitive neuroectodermal tumor (PNET), also referred to as extraskeletal Ewing's sarcoma, is a highly aggressive tumor, and it is seen typically in the soft tissues of the chest wall and paraspinal region but rarely arises in the kidney. A 27-year-old woman was presented with a left renal mass and underwent a radical nephrectomy. The pathological diagnosis was a primitive neuroectodermal tumor. Microscopically, there were sheets and lobules of cells with round to oval nuclei and coarse chromatin, as well as a Homer Wright rosette formation. Immunohistochemical analysis showed strongly positive staining of CD99 and negative staining of other neuroendocrine markers, such as synaptophysin and chromogranin.