Large Polygonal Cells Research Articles

Re-evaluation of hepatocyte replacement by recipient-derived cells after allogenic liver transplantation: Discrepancy between clinical observations and a rat model.

Reports suggest that hepatocyte replacement by recipient-derived cells is an active phenomenon after allogenic liver transplantation in rats. However, this phenomenon is rarely observed in humans, and further evaluation is necessary to bridge the gap between clinical practice and animal experiment. Fifty percent volume of the liver from green fluorescent protein (GFP) transgenic Lewis rats were transplanted into wild-type Dark Agouti (DA) rats, in which GFP negative hepatocytes were considered as host (DA rat)-derived cells. The transplanted liver was observed on whole imaging system and fluorescent microscope 7-10days after transplantation. As a different method from previous reports, hepatocytes isolated from transplanted livers were cultured, and the expression of GFP was examined. The sliced liver (2mm) after allogenic transplantation demonstrated decreased intensity of GFP signals compared with the positive control. The hematoxylin-eosin staining of the section revealed abundant infiltration of inflammatory cells, suggesting an immunological rejection reaction. Large polygonal cells with significantly decreased or negative GFP signals were also demonstrated, which was consistent with the results of previous studies. However, cell culturing demonstrated that none of the examined albumin positive large polygonal cells were host-derived cells. The same results were obtained irrespective of reconstruction of hepatic artery. Our result implies that rejection reaction does not promote parenchymal replacement by recipient-derived cells, in contrast to previous reports. If so, the phenomena occurring in rats are consistent with clinical observation of liver transplantation in humans.

Expression of area-specific M2-macrophage phenotype by recruited rat monocytes in duct-ligation pancreatitis.

Acute pancreatitis remains a disease of uncertain pathogenesis and no established specific therapy. Previously, we found a predominant increase and active proliferation of macrophages in the inflamed tissues of a rat duct-ligation pancreatitis model. To analyze the origin and possible role of these macrophages, we investigated their in situ cellular kinetics in a rat model of duct-ligation pancreatitis using a recently established method of multicolor immunostaining for macrophage markers and for proliferating cells with ethynyl deoxyuridine. To detect monocyte-derived macrophages, green fluorescent protein-transgenic (GFP+) leukocytes were transferred to monocyte-depleted recipients. In the inflamed pancreas, infiltrating macrophages were mainly two phenotypes, CD68+CD163− round cells and CD68+CD163+ large polygonal cells, both of which showed active proliferation. In the interlobular area, the proportions of CD68+CD163low and CD68+CD163high cells increased over time. Most expressed the M2-macrophage markers CD206 and arginase 1. In contrast, in the interacinar area, CD68+ cells did not upregulate CD163 and CD206, but ~30 % of them expressed the M1 marker nitric oxide synthase 2 on day 4. GFP+-recruited cells were primarily CD68+CD163− monocytes on day 1 and showed phenotypic changes similar to those of the monocyte non-depleted groups. In conclusion, infiltrating macrophages mostly formed two distinct subpopulations in different areas: monocyte-derived macrophages with the M2 phenotype in the interlobular area or non-M2 phenotype in the interacinar area. Involvement of resident macrophages might be minor in this model. These results are the first demonstration of an upregulated M2 phenotype in rat inflammatory monocytes, which may promote tissue repair.Electronic supplementary materialThe online version of this article (doi:10.1007/s00418-016-1406-y) contains supplementary material, which is available to authorized users.

Silent subtype 3 pituitary adenomas are not always silent and represent poorly differentiated monomorphous plurihormonal Pit-1 lineage adenomas

Originally classified as a variant of silent corticotroph adenoma, silent subtype 3 adenomas are a distinct histologic variant of pituitary adenoma of unknown cytogenesis. We reviewed the clinical, biochemical, radiological, immunohistochemical and ultrastructural features of 31 silent subtype 3 adenomas to clarify their cellular origin. Among 25 with clinical and/or radiological data, all were macroadenomas; there was cavernous sinus invasion in 30% of cases and involvement of the clivus in 17% of cases. Almost 90% of patients were symptomatic; 67% had mass effect symptoms, 37% were hypogonadal and 8% had secondary adrenal insufficiency. Significant hormonal excess in 29% of cases included hyperthyroidism in 17%, acromegaly in 8% and hyperprolactinemia above 150 μg/l in 4%. Two individuals with hyperprolactinemia who were younger than 30 years had multiple endocrine neoplasia type 1. Immunohistochemically, all 31 tumors were diffusely positive for the pituitary lineage-specific transcription factor Pit-1. Although three only expressed Pit-1, others revealed variable positivity for one or more hormones of Pit-1 cell lineage (growth hormone, prolactin, thyroid-stimulating hormone), as well as alpha-subunit and estrogen receptor. Most tumors exhibited perinuclear reactivity for keratins with the CAM5.2 antibody; scattered fibrous bodies were noted in five (16%) tumors. The mean MIB-1 labeling index was 4% (range, 1–9%). Fourteen cases examined by electron microscopy were composed of a monomorphous population of large polygonal or elongated cells with nuclear spheridia. Sixty-five percent of patients had residual disease after surgery; after a mean follow-up of 48.4 months (median 41.5; range=2–171) disease progression was documented in 53% of those cases. These data identify silent subtype 3 adenomas as aggressive monomorphous plurihormonal adenomas of Pit-1 lineage that may be associated with hyperthyroidism, acromegaly or galactorrhea and amenorrhea. Our findings argue against the use of the nomenclature ‘silent’ for these tumors. To better reflect the characteristics of these tumors, we propose that they be classified as ‘poorly differentiated Pit-1 lineage adenomas’.

Oncocytoma of the parotid gland: Dilemma for the cytopathologist

Oncocytoma is a rare benign tumor of the salivary glands usually seen in elderly patients in the sixth to eighth decade. Microscopically, the hallmark of this lesion is the presence of oncocytes that comprise the entire tumor. These are large polygonal cells which have abundant eosinophilic granular cytoplasm, and from central to eccentric round nucleus. Several reactive as well as neoplastic lesions of salivary glands often have concurrent oncocytic changes. On fine-needle aspiration cytology, all of them have overlapping morphological features, thus making the diagnosis difficult by cytology alone. We report a case of oncocytoma of the right parotid gland in a 32-year-old Indian male. Although the tumor was initially suspected on cytology, confirmation was possible only after histopathological examination. The main purpose of this case report is to discuss the cytological differential diagnosis of oncocytic lesions of salivary glands and simultaneously emphasize the importance of histopathology for arriving at conclusive diagnosis in such cases.

Association between p53-binding protein 1 expression and genomic instability in oncocytic follicular adenoma of the thyroid.

Oncocytic follicular adenomas (FAs) of the thyroid are neoplasms of follicular cell origin that are predominantly composed of large polygonal cells with eosinophilic and granular cytoplasm. However, the pathological characteristics of these tumors are largely unexplored. Both the initiation and progression of cancer can be caused by an accumulation of genetic mutations that can induce genomic instability. Thus, the aim of this study was to evaluate the extent of genomic instability in oncocytic FA. As the presence of p53-binding protein 1 (53BP1) in nuclear foci has been found to reflect DNA double-strand breaks that are triggered by various stresses, the immunofluorescence expression pattern of 53BP-1 was assessed in oncocytic and conventional FA. The association with the degree of DNA copy number aberration (CNA) was also evaluated using array-based comparative genomic hybridization. Data from this study demonstrated increased 53BP1 expression (i.e., "unstable" expression) in nuclear foci of oncocytic FA and a higher incidence of CNAs compared with conventional FA. There was also a particular focus on the amplification of chromosome 1p36 in oncocytic FA, which includes the locus for Tumor protein 73, a member of the p53 family implicated as a factor in the development of malignancies. Further evaluations revealed that unstable 53BP1 expression had a significant positive correlation with the levels of expression of Tumor protein 73. These data suggest a higher level of genomic instability in oncocytic FA compared with conventional FA, and a possible relationship between oncocytic FA and abnormal amplification of Tumor protein 73.

Efficiency of Human Epiphyseal Chondrocytes with Differential Replication Numbers for Cellular Therapy Products.

The cell-based therapy for cartilage or bone requires a large number of cells; serial passages of chondrocytes are, therefore, needed. However, fates of expanded chondrocytes from extra fingers remain unclarified. The chondrocytes from human epiphyses morphologically changed from small polygonal cells to bipolar elongated spindle cells and to large polygonal cells with degeneration at early passages. Gene of type II collagen was expressed in the cells only at a primary culture (Passage 0) and Passage 1 (P1) cells. The nodules by implantation of P0 to P8 cells were composed of cartilage and perichondrium. The cartilage consisted of chondrocytes with round nuclei and type II collagen-positive matrix, and the perichondrium consisted of spindle cells with type I collage-positive matrix. The cartilage and perichondrium developed to bone with marrow cavity through enchondral ossification. Chondrogenesis and osteogenesis by epiphyseal chondrocytes depended on replication number in culture. It is noteworthy to take population doubling level in correlation with pharmaceutical efficacy into consideration when we use chondrocytes for cell-based therapies.

Malignant renal epithelioid angiomyolipoma: A case report and review of the literature.

Malignant renal epithelioid angiomyolipoma (EAML) is rare, and currently there is no malignant criteria for its pathological diagnosis. In the present study, the case of a patient who suffered malignant renal EAML and underwent nephrectomy is reported. The histological patterns of the tumor were composed of sheets or nests of large polygonal epithelioid cells and thick-walled blood vessels, with clear mitoses. Immunohistochemistry demonstrated that the epithelioid and smooth muscle cells characteristically expressed human melanoma black-45, epithelial membrane antigen and actin. Pathological evaluation revealed malignant EAML with regional lymph node metastases. Magnetic resonance imaging and X-ray examination identified multiple liver and lung nodules at 16 months post-surgery. Since the patient did not respond to the initial treatment with doxorubicin and cisplatin, sorafenib was subsequently administered. However, the treatment was not effective, and the patient succumbed to multiple metastases six months later.

Description Of An Anaplastic Rhabdomyosarcoma In A Cockatiel (Nymphicus Hollandicus)

Abstract Rhabdomyosarcoma is a malignant tumor of the skeletal muscles that is occasionally observed in free-living and pet birds. A case of malignant rhabdomyosarcoma in the musculature of the right wing of a captive female cockatiel (Nymphicus hollandicus) was investigated. The clinical aspect and radiographic images suggested an invasive neoplasm. Histologically, the tumor was composed of a patternless array of large primitive polygonal cells or sheets of bizarre cells with giant nuclei and atypical mitoses set in a collagenous stroma. Anaplastic cells were poorly differentiated and exhibited notable cellular and nuclear pleomorphism. Nuclei showed extreme variability in number, size, shape, chromatin distribution and nucleolar size and number. The cross striations were encountered in elongated multinucleated cells known as “strap cells” and in ovoid cells known as “racquet cells” and numerous mitotic figures were also observed. Neoplastic cells were positive for muscle actin and negative for desmin, suggesting the diagnosis of anaplastic rhabdomyosarcoma. It is the first reliable record of a rhabdomyosarcoma in a cockatiel (Nymphicus hollandicus) in Romania.

Abstract P5-07-04: Characterization of a new canine inflammatory mammary cancer (IMC) cell line (IPC-366)

Abstract Spontaneous canine inflammatory mammary cancer (IMC) shares epidemiologic, histopathological and clinical characteristics with the disease in humans and has been proposed as a natural model for human inflammatory breast cancer (IBC). Few cell lines are available to study IBC, such us SUM 149, SUM 190 and MDA-IBC3. The aim of this study was to characterize a new cell line from IMC (IPC-366) for the comparative study of both IMC and IBC. Tumors cells from a female dog with clinical IMC were collected. The pathological diagnosis of IMC was confirmed at the Veterinary Pathology Service of UCM- Veterinary Clinical Hospital. The cells were grown under adherent conditions in DMEM/F12 with 5% fetal bovine serum and 1% antibiotics (streptomycin and penicillin). The growth and mammospheres production capability, and cytological, ultrastructural and immunohistochemical (IHC) characteristics of IPC-366 were evaluated. Tumorigenicity and metastatic potential of IPC-366 were also assessed by inoculating the cells on the mammary fat pad of 18 female Balb/SCID mice and the development of tumor was monitored by imaging and luciferase assay. Microscopic examination of tumor revealed an epithelial morphology with marked anysocytosis. Doubling time of the tumor cells was approximately 24 h. Under non-adherent conditions, IPC-366 cells formed mammospheres in approximately 3 days. Cytological and histological examination of smears and ultrathin sections by electron microscopy revealed that IPC-366 is formed by highly malignant large round or polygonal cells characterized by marked atypia and prominent nucleoli and frequent multinucleated cells. Some cells had cytoplasmic empty spaces covered by cytoplasmic membrane resembling capillary endothelial cells, a phenomenon described as vasculogenic mimicry. IHC characterization of IPC-366 was basal-like: epithelial cells (AE1/AE3+, CK14+, vimentin+, actin-, p63-, ER-, PR-, HER-2 – (DAKO, HER2 P4 ), overexpressed COX-2 and high Ki-67 proliferation index (87.15 %). Imaging and luciferase assay revealed that at 3 weeks after inoculating the IPC-366 cells, a tumor mass was found in 50 % of mice. At 8 weeks after inoculation metastases in lung, liver and lymph nodes were found. Xenograph tumors maintained the original IHC characteristics of the female dog tumor. In summary, the cell line IPC-366 is a fast growing malignant triple negative cell line model of inflammatory mammary carcinoma that can be used for the comparative study of both IMC and IBC. Citation Format: Sara Caceres, Laura Peña, Lara C Alvarez de la Cerda, Maria J Illera, Richard Larson, Hui Gao, Bisrat G Debeb, Wendy A Woodward, James M Reuben, Juan C Illera. Characterization of a new canine inflammatory mammary cancer (IMC) cell line (IPC-366) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-07-04.

Establishment and characterization of a new cell line of canine inflammatory mammary cancer: IPC-366.

Canine inflammatory mammary cancer (IMC) shares epidemiologic, histopathological and clinical characteristics with the disease in humans and has been proposed as a natural model for human inflammatory breast cancer (IBC). The aim of this study was to characterize a new cell line from IMC (IPC-366) for the comparative study of both IMC and IBC. Tumors cells from a female dog with clinical IMC were collected. The cells were grown under adherent conditions. The growth, cytological, ultrastructural and immunohistochemical (IHC) characteristics of IPC-366 were evaluated. Ten female Balb/SCID mice were inoculated with IPC-366 cells to assess their tumorigenicity and metastatic potential. Chromosome aberration test and Karyotype revealed the presence of structural aberration, numerical and neutral rearrangements, demonstrating a chromosomal instability. Microscopic examination of tumor revealed an epithelial morphology with marked anysocytosis. Cytological and histological examination of smears and ultrathin sections by electron microscopy revealed that IPC-366 is formed by highly malignant large round or polygonal cells characterized by marked atypia and prominent nucleoli and frequent multinucleated cells. Some cells had cytoplasmic empty spaces covered by cytoplasmic membrane resembling capillary endothelial cells, a phenomenon that has been related to s vasculogenic mimicry. IHC characterization of IPC-366 was basal-like: epithelial cells (AE1/AE3+, CK14+, vimentin+, actin-, p63-, ER-, PR-, HER-2, E-cadherin, overexpressed COX-2 and high Ki-67 proliferation index (87.15 %). At 2 weeks after inoculating the IPC-366 cells, a tumor mass was found in 100 % of mice. At 4 weeks metastases in lung and lymph nodes were found. Xenograph tumors maintained the original IHC characteristics of the female dog tumor. In summary, the cell line IPC-366 is a fast growing malignant triple negative cell line model of inflammatory mammary carcinoma that can be used for the comparative study of both IMC and IBC.

Rapid evaluation of fresh ex vivo kidney tissue with full-field optical coherence tomography

Background: Full-field optical coherence tomography (FFOCT) is a real-time imaging technique that rapidly generates images reminiscent of histology without any tissue processing, warranting its exploration for evaluation of ex vivo kidney tissue. Methods: Fresh tissue sections from tumor and adjacent nonneoplastic kidney (n = 25 nephrectomy specimens; clear cell renal cell carcinoma (CCRCC) = 12, papillary RCC (PRCC) = 4, chromophobe RCC (ChRCC) = 4, papillary urothelial carcinoma (PUC) = 1, angiomyolipoma (AML) = 2 and cystic nephroma = 2) were imaged with a commercial FFOCT device. Sections were submitted for routine histopathological diagnosis. Results: Glomeruli, tubules, interstitium, and blood vessels were identified in nonneoplastic tissue. In tumor sections, the normal architecture was completely replaced by either sheets of cells/trabeculae or papillary structures. The former pattern was seen predominantly in CCRCC/ChRCC and the latter in PRCC/PUC (as confirmed on H&E). Although the cellular details were not very prominent at this resolution, we could identify unique cytoplasmic signatures in some kidney tumors. For example, the hyper-intense punctate signal in the cytoplasm of CRCC represents glycogen/lipid, large cells with abundant hyper-intense cytoplasm representing histiocytes in PRCC, and signal-void large polygonal cell representing adipocytes in AML. According to a blinded analysis was performed by an uropathologist, all nonneoplastic tissues were differentiated from neoplastic tissues. Further, all benign tumors were called benign and malignant were called malignant. A diagnostic accuracy of 80% was obtained in subtyping the tumors. Conclusion: The ability of FFOCT to reliably differentiate nonneoplastic from neoplastic tissue and identify some tumor types makes it a valuable tool for rapid evaluation of ex vivo kidney tissue e.g. for intraoperative margin assessment and kidney biopsy adequacy. Recently, higher resolution images were achieved using an experimental FFOCT setup. This setup has the potential to further increase the diagnostic accuracy of FFOCT.

Renal collision tumour of papillary cell carcinoma and chromophobe cell carcinoma with sarcomatoid transformation: A case report and review of the literature.

The simultaneous occurrence of different histological types of adjacent neoplasms in the same organ is called a collision tumour, and rarely occurs in the kidney. A 63-year-old female presented to the urology department with a 1-month history of a painless hematuria. The computed tomography scans of the abdomen revealed 2 heterogeneous incidental right renal masses. The patient underwent radical nephrectomy including lymphadenectomy without adjuvant therapy. Histopathological examination showed a type 2 renal collision tumour of the papillary renal cell carcinoma with eosinophilic cytoplasm and pseudostratified nuclei on papillary cores, and chromophobe renal cell carcinoma characterized by large polygonal cells with transparent reticulated cytoplasm and prominent cell membranes, which exhibited sarcomatoid transformation in the local area. Routine follow-up demonstrated no local or distant metastasis signs of recurrence at 20 months.

Granular Cell Tumor of the Testicular Tunica Albuginea

Granular cell tumor (GCT) is exceedingly rare in the genitourinary tract. We report a case of GCT arising in the tunica albuginea of the testis. A 42-year-old male presented with a painless left testicular mass. Scrotal ultrasound studies showed an intratesticular mass that was suspicious for a testicular malignancy; a left orchiectomy was subsequently performed. Grossly, there was a well-circumscribed tumor mass in the periphery of the testis abutting the tunica albuginea. Microscopically, the tumor was poorly delimited and located in the tunica albuginea with minimal infiltration to the underlying testicular parenchyma. The lesion consisted of clusters and sheets of large polygonal cells dissected by fibrous septa. The tumor cells had indistinct cellular borders, abundant granular eosinophilic cytoplasm, and small nuclei with indistinct nucleoli. No cytologic atypia or increased mitotic activity was seen. Immunohistochemically, the tumor cells were positive for S-100, inhibin-α, and CD68 and negative for calretinin, Melan-A, and WT-1. Ki-67 showed a low proliferation index (<1%). The morphology, in conjunction with immunohistochemical profile, led to a diagnosis of GCT of the tunica albuginea. Although GCT can occur in almost any location of the body, it has not been described to involve the human testis.

Pleomorphic Rhabdomyosarcoma in upper limb in an adult

Rhabdomyosarcoma (RMS) is the most common form of soft tissue sarcoma in the first 2 decades of life, with a peak age incidence in very young children. Due to the rarity of adult RMS, information regarding its clinical and biologic characteristics is very limited. We report a case of pleomorphic RMS of upper extremity in a 50-year-old man. There was no metastasis of the tumor. The patient underwent surgery with enbloc excision of the tumor. Histopathological examination showed typical features of pleomorphic RMS composed of large polygonal pleomorphic cells with eosinophilic cytoplasm and plenty of large multinucleated tumor giant cells having bizarre nuclei. Postoperatively patient took radiotherapy. There was no recurrence of tumor with follow-up of 2 years.

Melanotic neuroectodermal tumor of infancy: Presentation of a case

The melanotic neuroectodermal tumor of infancy (MNTI) is a fairly rare, benign, pigmented lesion with a rapid expansile growth and a high recurrence rate that commonly occurs in the anterior maxilla of infants younger than 1 year and mainly in the first 6 months of life. Microscopically, large polygonal epithelioid cells resembling melanocytes, with variable deposits of melanin, and smaller neuroblast-like round cells characterize MNTI. Malignant transformation may occur. The tumor was first described by Krompecher in 1918 as a congenital melanocarcinoma. In 1992, the designation MNTI was accepted by and used in the World Health Organization classification of odontogenic tumors. One such case was diagnosed in the department of oral pathology and microbiology and is presented.

A Case of Thyroid Granular Cell Tumor

Granular cell tumor is an uncommon neoplasm that can occur everywhere in the human body. Granular cell tumor of the thyroid gland is very rare and only eight cases of thyroid granular cell tumor have been reported. Histopathologically, granular cell tumor consists of large polygonal cells with small dark nuclei and abundant, fine, granular eosinophilic cytoplasm that show posi tive immunohistochemical staining using S-100 protein. Surgical excision is the treatment of choice for granular cell tumor. Recurrence is rare, but inadequate resection of granular cell tumor may cause local recurrence. We have experienced one case of thyroid granular cell tumor that we report here with a review of literatures. � Korean J Otorhinolaryngol-Head Neck Surg 2014;57:108-11 Key WordsZZGranular cell tumor ㆍThyroid.

Fine‐needle aspiration cytomorphology of sebaceous lymphadenoma of the salivary gland

Sebaceous lymphadenoma (SLA) is a histologic variant of lymphadenoma or sebaceous adenoma of the salivary gland. The fine-needle aspiration (FNA) cytology of SLA has not been well-described. In this report, we reported a case that involved an 81-year-old male with a long-standing left parotid mass and was diagnosed on FNA cytology. The FNA smears showed clusters of three types of epithelial cells in a background of abundant lymphoid cells, macrophages and abundant proteinaceous materials. The predominant epithelial cells were large polygonal cells with abundant cytoplasm filled with multiple, uniform, small, and clear vacuoles, ill-defined cytoplasmic borders, and small centrally located round nuclei with finely granular chromatin, conspicuous nucleoli and indented nuclear membranes apparently imprinted by cytoplasmic vacuoles. These cells were surrounded by polygonal or flat cells with less or more dense cytoplasm, indistinct cell borders and round or oval small nuclei with smooth nuclear membranes, which correspond to germinative or basaloid cells. Some cells had granular cytoplasm. Large three dimensional clusters of nonkeratinized squamous cells have oval nuclei containing evenly distributed chromatin, and scant to moderate dense cytoplasm that were arranged in a "stream of fish" pattern. Rare granulomas and cystic contents (degenerated cells, inflammatory cells, macrophages, and abundant granular debris/proteinaceous material) were also seen. The diagnosis of SLA was confirmed by the surgical resection.

Simultaneous Viewing of Individual Cells and Ambient Microvasculature Using Optical Absorption and Fluorescence Contrasts

Viewing individual cells and ambient microvasculature simultaneously is crucial for understanding tumor angiogenesis and microenvironments. We developed a confocal fluorescence microscopy (CFM) and photoacoustic microscopy (PAM) dual-modality imaging system that can assess fluorescent contrast and optical absorption contrast in biologic samples simultaneously. After staining tissues with fluorescent dye at an appropriate concentration, each laser pulse can generate not only sufficient fluorescent signals from cells for CFM but also sufficient photoacoustic signals from microvessels for PAM. To explore the potential of this system for diagnosis of bladder cancer, experiments were conducted on a rat bladder model. The CFM image depicts the morphology of individual cells, showing not only large polygonal umbrella cells but also intracellular components. The PAM image acquired at the same time provides complementary information on the microvascular distribution in the bladder wall, ranging from large vessels to capillaries. This device provides an opportunity to realize both histologic assay and microvascular characterization simultaneously. The combination of the information of individual cells and local microvasculature in the bladder offers the capability of envisioning the viability and activeness of these cells and holds promise for more comprehensive study of bladder cancer in vivo.

Adult Rhabdomyoma of the Extremity

Adult rhabdomyoma is a rare benign tumor. It mainly occurs in the head and neck region and rarely occurs outside the head and neck region. We present an extremely rare case of the adult rhabdomyoma arising in the left foot in a 46-year-old male. Microscopically, large polygonal cells and large strap-shaped cells were observed. This is the third case of adult rhabdomyoma arising in an extremity.

Cytoplasmic non-epithelial mucin accumulation associated with CD44 in an astrocytic tumor with signet ring features

We report a case of an atypical astrocytic tumor rich in signet ring cells with cytoplasmic mucin and glycogen in the left lower temporal lobe of the brain found in a Japanese female tricenarian. The signet ring cell cytoplasm contained bovine testicular hyaluronidase sensitive non-epithelial mucin together with CD44 and laminin. Glycogen was also detected. After subtotal resection, the residual tumor rapidly enlarged; hence, it was finally extirpated 8 months later followed by post-surgical irradiation. The recurrent tumor did not have signet ring cells and was entirely comprised of solid nests of large pale polygonal cells filled with glycogen and hyperchromatic nuclei. Mucin was not demonstrated in their cytoplasm, but their surface was diffusely coated with non-epithelial mucin together with CD44. The results of our analysis revealed that non-epithelial mucin could accumulate in or on the surface of neoplastic astrocytes in close association with CD44, findings that give new insights into the spectrum of non-epithelial mucin metabolism in astrocytic tumors. The tumor has not recurred for more than 3 years after the irradiation therapy following the second surgery, but further clinical observation is needed to evaluate the exact clinical behavior of this unusual tumor.