First Report of Fusarium oxysporum f. sp. cubense Tropical Race 4 Associated with Panama Disease of Banana outside Southeast Asia.

Fusarium wilt or Panama disease of banana, caused by Fusarium oxysporum f. sp. cubense (Foc), is among the most destructive plant diseases (3). Race 1 ravaged 'Gros Michel'-based export trades until the cultivar was replaced by resistant Cavendish cultivars. However, a new variant of Foc, tropical race 4 (TR4), was identified in Southeast Asia in 1992 and has spread throughout the region (3). Cavendish clones, which are most important in subsistence and export production, are among the wide range of cultivars that are affected, and there is a huge concern that TR4 will further disseminate in Africa since its presence was announced in November 2013 and move into Latin America, thereby threatening other vital banana-growing regions. In Jordan, Cavendish bananas are produced on 1,000 to 1,500 ha in the Jordan Valley (32°N, 35.5°E). In 2006, symptoms of Fusarium wilt were observed and sampled for the isolation of Foc. On half-strength PDA amended with 100-ppm streptomycin sulfate, pale salmon-colored colonies with floccose mycelia developed consistently from surface-disinfested xylem. Single microconidia from these colonies were transferred to half-strength PDA, and conidia and mycelia from these monospore colonies were stored at -80°C in 15% glycerol. On banana leaf agar (Co60-irradiated leaf tissue on water agar), isolates resembled F. oxysporum phenotypically by producing infrequent three- to five-celled macroconidia, copious, usually aseptate microconida on monophialides, and terminal and intercalary chlamydospores after 2 weeks (2). With nitrate-nonutilizing (nit) mutants and testers for different vegetative compatibility groups (VCGs), each of seven examined monospore isolates were placed in VCG 01213, which contains only strains of TR4 (3). Total DNA was extracted from six isolates and PCR analyses, which confirmed their identity as TR4 (1). Subsequently, one of the isolates (JV11) was analyzed for pathogenicity. Inoculum production and inoculation were according to (1) by dipping (30 min) root-wounded 10-week-old plants of the Cavendish cv. Grand Naine in 2 liters of spore suspension (1.0 × 106 spores/ml). Inoculated plants were then placed in sand in 3-liter pots under 28°C, 70% relative humidity, and a 16/8-h light/darkness photoperiod. Sets of three plants were each treated with either JV11 or two TR4 controls (isolate II-5 and a strain isolated from an affected Cavendish plant in Mindanao, Philippines, both of which were diagnosed as TR4 by PCR and pathogenicity analyses). Control sets were either treated with race 1 originating from Cruz das Almas, Bahia, Brazil (1), or water. After 2 weeks, plants inoculated with JV11 and TR4 controls produced typical symptoms of Fusarium wilt. After 4 weeks, tissue was collected from all plants and plated on Komada's medium. TR4 was directly confirmed by PCR (1), either directly from symptomatic plants (JV11 and TR4 controls), or from isolates that were recovered from these plants. Nothing was re-isolated from race 1 inoculated plants and water controls, which remained asymptomatic. This is the first report of TR4 affecting Cavendish outside Southeast Asia, is its northernmost outbreak, and represents a dangerous expansion of this destructive race. Currently, 80% of the Jordan Valley production area is affected by Fusarium wilt, and 20 to 80% of the plants are affected in different farms. References: (1) M. A. Dita et al. Plant Pathol. 59:348, 2010. (2) J. F. Leslie and B. A. Summerell. The Fusarium Lab Manual. Blackwell, Ames, 2006. (3) R. C. Ploetz. Phytopathology 96:653, 2006.

Characterization of foam cells in nipple aspirate fluid.

Foam cells with abundant vacuolated cytoplasm are prominent in most samples of spontaneous nipple discharge, nipple aspirate fluid, and ductal lavage. Although several investigators have attempted to characterize these cells, there is no consensus about whether these cells are derived entirely from macrophages or from both ductal epithelial cells and macrophages. Using immunocytochemical methods, we studied 20 paired specimens of nipple aspirate fluid containing abundant foam cells obtained from the involved breast of women with in situ or invasive carcinoma and from the contralateral normal breast. We used a cocktail of anticytokeratin antibodies including AE1, AE3, and CAM5.2 and the macrophage marker KP1 (CD68). In addition, we examined samples by electron microscopy. The foam cells were consistently negative for cytokeratin and positive for CD68. In every case electron microscopy of these cells revealed irregular outlines with short cytoplasmic processes. The cytoplasm was abundant and contained numerous lysosomes, a small Golgi complex, lipid droplets, mitochondria, and short profiles of rough endoplasmic reticulum. There was no evidence, however, of cell junctions or tonofilaments. The immunocytochemical and electron microscopic findings of our study together clearly support a macrophage derivation for foam cells in nipple aspirate fluid.

Primary signet-ring cell carcinoma of lung: immunohistochemical study and comparison with non-pulmonary signet-ring cell carcinomas.

Signet-ring cell carcinoma (SRCC) of lung is a rare variant of pulmonary adenocarcinoma. In view of this rarity, the question of whether an SRCC is primary pulmonary or metastatic arises frequently because the majority of SRCCs seen in lung are metastatic tumors having arisen in stomach, colon, or breast. On routine histologic examination it is difficult to distinguish between pulmonary SRCC from SRCC metastasizing from other organs. Thyroid transcription factor-1 (TTF-1) is a homeodomain-containing transcription factor that is almost exclusively expressed in thyroid and pulmonary epithelial cells. TTF-1 expression has been demonstrated in various neoplasms of lung; however, the expression of TTF-1 in SRCCs has not been investigated so far. In the present study, using an immunoperoxidase staining procedure on paraffin sections, we investigated the expression of TTF-1, cytokeratin 7, cytokeratin 20, and villin (a specific marker expressed in tumors of the digestive tract, renal proximal tubules, and hepatic bile ducts) in 32 SRCCs from various organs (17 lung, 5 breast, 5 stomach, and 5 colon). Fourteen (82.4%) of 17 pulmonary SRCCs exhibited TTF-1 positivity, whereas none of the SRCCs of other organs were positive for TTF-1. A cytokeratin profile (CK7+/CK20-) was identified in 94.1% of pulmonary SRCC, and although it differed from the profile exhibited in colonic SRCCs (CK7-/CK20+), a similar profile was seen in breast SRCCs and some SRCCs arising in the stomach. Villin was identified in 29.4% of pulmonary SRCCs and 20% (one case) arising in the breast. Although the pattern of villin immunostaining exhibited by nondigestive tract SRCCs (cytoplasmic) differed from those of digestive tract SRCCs (membranous), distinguishing between the two groups based on their pattern of immunostaining alone would be difficult. The results of this study indicate that TTF-1 is expressed in a high percentage of pulmonary SRCCs and is very specific and that TTF-1 would be extremely valuable in distinguishing pulmonary SRCCs from those arising in other organs.

Reticulum cell sarcoma of lymph node with mixed dendritic and fibroblastic features.

We report a case of clinically aggressive reticulum cell sarcoma with mixed follicular dendritic cell (FDC) and fibroblastic reticular cell (FRC) features. Histologically, the tumor was confined to lymph nodes occurring as a multifocal epithelioid and spindle cell proliferation with appreciable mitotic rate and numerous admixed non-neoplastic B-cells. Ultrastructural examination revealed elongated cells with prominent nucleoli, interdigitating cell processes and frequent desmosomes. These features are typical of FDC sarcoma. However, immunohistochemical stains showed no expression of antigens characteristic of FDCs, including CD21, CD23 and CD35. Cytogenetic characterization of this tumor, by conventional G-banding and multicolor spectral karyotyping, revealed multiple clonal chromosomal aberrations, including del(X)(p11.4) and add (21)(p11.2). Gene expression analysis by cDNA microarray of RNA obtained from short-term tumor cultures revealed high-level expression of a set of genes (including PDGF receptor-alpha and -beta, certain metalloproteinases, and CD105) that were also highly expressed in cultures of nodal FRC cultured from non-neoplastic lymph nodes. We propose that this tumor represents a nodal sarcoma with intermediate differentiation between FDCs and FRCs. This case adds to the diversity of tumors that may arise from lymph node stroma and supports a possible relationship between the FDC and FRC lineages.

Pulmonary granuloma caused by Pseudomonas andersonii sp nov.

Pulmonary granuloma is a common lesion for which gram-negative bacteria are rarely implicated as a cause. Hence, most physicians are unaware of this etiology. We isolated a gram-negative bacterium from a surgically resected pulmonary granuloma in a 42-year-old, nonimmunocompromised woman. Within the necrotizing granuloma, numerous organisms also were demonstrated by Gram stain, suggesting a cause-disease relationship. Characterization of the bacterium by sequence analysis of the 16S ribosomal gene, cellular fatty acid profiling, and microbiologic studies revealed a novel bacterium with a close relationship to Pseudomonas. We propose a new species for the bacterium, Pseudomonas andersonii. These results suggest that the differential diagnosis of a lung granuloma also should include this gram-negative bacterium as a potential causative agent, in addition to the more common infections caused by acid-fast bacilli and fungi. This bacterium was shown to be susceptible to most antibiotics that are active against gram-negative bacteria.

Low-grade (fibromatosis-like) spindle cell carcinoma of the breast.

Spindle cell carcinoma of the breast, a variant of metaplastic carcinoma, includes a wide spectrum of lesions with histomorphologic and nuclear features ranging from overtly malignant to mildly atypical. Spindle cell carcinomas with mildly atypical features may resemble fasciitis, fibromatosis, or myofibroblastic tumors and therefore are often misinterpreted as such. A recent study has suggested that spindle cell carcinomas with a dominant fibromatosis-like phenotype, unlike spindle cell carcinomas in general, have no propensity for distant metastasis and should be termed "tumors" rather than "carcinomas." To investigate the question of fibromatosis-like spindle cell breast carcinoma (FLSpCCs) metastatic potential, we studied cases of FLSpCC seen at the University of Texas M.D. Anderson Cancer Center between 1987 and 2000. Clinical, pathologic, and immunophenotypic features were reviewed, with emphasis on biologic behavior and predictors of clinical outcome. Our series included 24 women who ranged in age from 55 to 85 years (mean 66 years). Tumor size ranged from 1.0 to 5 cm (mean 2.8 cm). Most tumors were grossly well defined but had microscopic infiltrative borders. Tumors showed a dominant fibromatosis-like or myofibroblastic-like growth pattern with prominent collagenization. Inflammatory infiltrate was noted in the majority of tumors. Cytokeratin-positive cells were seen in all cases and usually appeared as cords or sheets of polygonal cells; isolated cytokeratin-positive cells were rare. In most tumors immunoreactivity for smooth muscle actin (SMA) was confined to the cytokeratin-negative cells. In five cases intense co-expression of cytokeratin and SMA was noted. None of the tumors showed immunoreactivity for smooth muscle heavy chain myosin, estrogen receptors, progesterone receptors, or HER-2/neu. Ki-67 expression was noted in fewer than 5% of tumor cells. Treatment consisted of local excision (seven cases) or modified radical mastectomy (13 cases). Treatment was unknown in four cases. In patients who underwent axillary nodal dissection, no lymph node metastases were found. Two of the six patients who underwent local excision developed local recurrence. Two patients who underwent modified radical mastectomy developed lung metastases within 2 years after the initial diagnosis. The metastatic tumors were histologically similar to the primary tumors. Our findings indicate that FLSpCCs have the potential for local recurrence and distant metastasis and should be treated accordingly. Because FLSpCCs may be underdiagnosed as benign, the use of immunohistochemical studies, especially for cytokeratins and SMA, is essential in the evaluation of any spindle cell proliferations of the breast.

Pancreatic acinar cell carcinoma.

Acinar cell carcinomas (ACCs) are rare neoplasms that represent less than 2% of all exocrine tumors of the pancreas. Although they occur more often in adults between the 5th and 7th decades of life, a few cases have been reported in children. Histologically, ACCs can resemble islet cell tumors, but they differ in their ultrastructural and immunohistochemical features. Although ACCs present a bland histology, they are highly malignant and the survival of patients with these tumors, even though better than that of those with ductal cell carcinomas, is generally poor.

Varietes and serotypes of Cryptococcus neoformans clinical isolates in Colombia.

The aim of this study was to contribute to the knowledge of the geographic distribution of Cryptococcus neoformans varieties, in Colombian patients, and to determine the mating types of such varieties. A total of 370 clinical isolates were studied. C. neoformans var. neoformans was identified in 95.2% of them. C. neoformans var. gattii in 4.8%, 4.5% being serotype B and 0.3%, serotype C. Fifty-five of the 74 (74%) isolates studied were mating type "alpha", all of them C. neoformans var. neoformans. Serotype C had been previously reported only once in South American countries.

Insulinoma with fibrillar inclusions and acinar cell elements.

Islet cell tumors associated with exocrine elements are rare. An insulinoma was removed from the head of the pancreas of a 33-year-old woman. Ultrastructural and immunohistochemical studies demonstrated that, in addition to the endocrine cells, the tumor had a small population of cells with an acinar cell morphology. Rare cells exhibiting both endocrine and exocrine features (amphicrine cells) were also identified. Another unusual finding in this case was the presence of a large number of intracytoplasmic filamentous inclusions that, even though they have been observed in other neoplasms, have not previously been reported in endocrine tumors of the pancreas. The demonstration of cells with mixed endocrine features supports the concept that both the endocrine and exocrine portions of the components of the pancreas have a common embryologic origin.

Ciliated epithelia in the urethra: case report and literature review.

The presence of ciliated epithelial cells in the urethra has not been well recognized. Only two reports in the literature, both of which used scanning microscopy studies, have described this phenomenon. In this report, we illustrate the presence of scattered, ciliated epithelial cells in penile urethral biopsy specimens from a 38-year-old man with a history of bladder calculi and hematuria, by both light and transmission electron microscopy studies. The cilia in the urethra showed typical light microscopic and ultrastructural features of those seen in other organs. These ciliated cells are present in association with urothelial papilloma, condyloma acuminatum and acute inflammation of the urethra. These findings suggest that ciliated cells in the penile 0 urethra might be a consequence of metaplastic change of the urothelium, secondary to local stimulation or irritation.

Localized (solitary) fibrous tumor of the pleura.

Clinical, light microscopic, ultrastructural, and immunocytochemical features of localized fibrous tumor of the pleura are reviewed. The differential diagnosis of the benign tumors can be uncomplicated, but atypical variants and malignant forms require the exclusion of other tumors included in the broad array of spindle cell neoplasms that can arise in or extend to a serosal surface. Electron microscopy is useful, but immunostaining procedures offer more extensive and reliable help in reaching the correct diagnosis. Tumors histologically similar to localized fibrous tumor of the pleura have been described in a number of extraserosal locations. Some localized fibrous tumors may be true fibromas, whereas the typical pleural tumor appears to arise from the subserosal mesenchymal cell and is composed of CD34-positive cells which are more primitive in their morphology than mature fibroblasts.

Acinar cell carcinoma of the pancreas.

Four cases of acinar cell carcinoma of the pancreas are reported. An acinar cell carcinoma can resemble an islet cell tumor by routine light microscopy but the two differ considerably in their fine structure and immunostaining properties. Although cells of both tumors contain numerous dense-core granules, their size ranges are different, and atypical forms occur in the acinar cell tumors, including elongated bodies filled with filaments. Many mitochondria-rough endoplasmic reticulum complexes were present in one tumor. In a liver metastasis, nests of endocrine cells were discovered amid the groups of acinar cells, and some of the endocrine granules contained rectangular cores.

Malignant fibrous histiocytoma: an ultrastructural perspective.

Malignant fibrous histiocytoma is a frequent diagnosis, but the relationship of the tumors to histologically similar soft tissue neoplasms is controversial. In this study, 157 examples representing the 4 main subtypes were reviewed by light microscopy and each tumor was studied with the electron microscope. Immunohistochemical stains were performed on 77 tumors. Electron micrographs on 100 fibrosarcomas were reviewed for comparison. Malignant fibrous histiocytomas often closely resemble fibrosarcomas at the ultrastructural level and differences between the two are generally of degree only. Evidence for true histiocytic differentiation was not found. The immunohistochemical results did not contradict the authors' impression from electron microscopy that malignant fibrous histiocytoma forms part of the histologic spectrum of tumors of fibroblasts.

In situ tolerance within the central nervous system as a mechanism for preventing autoimmunity.

Multiple sclerosis (MS) is believed to be an autoimmune disease in which autoreactive T cells infiltrate the central nervous system (CNS). Animal models of MS have shown that CNS-specific T cells are present in the peripheral T cell repertoire of healthy mice and cause autoimmune disease only when they are activated by immunization. T cell entry into the CNS is thought to require some form of peripheral activation because the blood-brain barrier prohibits trafficking of this tissue by naive cells. We report here that naive T cells can traffic to the CNS without prior activation. Comparable numbers of T cells are found in the CNS of both healthy recombinase activating gene (Rag)(-/)- T cell receptor (TCR) transgenic mice and nontransgenic mice even when the transgenic TCR is specific for a CNS antigen. Transgenic T cells isolated from the CNS that are specific for non-CNS antigens are phenotypically naive and proliferate robustly to antigenic stimulation in vitro. Strikingly, transgenic T cells isolated from the CNS that are specific for myelin basic protein (MBP) are also primarily phenotypically naive but are unresponsive to antigenic stimulation in vitro. Mononuclear cells from the CNS of MBP TCR transgenic but not nontransgenic mice can suppress the response of peripheral MBP-specific T cells in vitro. These results indicate that naive MBP-specific T cells can traffic to the CNS but do not trigger autoimmunity because they undergo tolerance induction in situ.

Value of thyroid transcription factor-1 immunostaining in distinguishing small cell lung carcinomas from other small cell carcinomas.

The distinction between small cell lung carcinoma (SCLC) and small cell carcinomas of other sites is difficult by routine histology. Thyroid transcription factor-1 (TTF-1) is a homeodomain-containing transcription factor that is selectively expressed in thyroid and pulmonary epithelial cells. TTF-1 expression has also been demonstrated in adenocarcinomas of the thyroid and lung, and SCLC. However, the value of TTF-1 immunostaining in discriminating between SCLC and nonpulmonary small cell carcinomas has not been investigated. In the present study using an immunoperoxidase staining procedure on paraffin sections, we investigated the expression of TTF-1 and cytokeratin 20 (CK20), a marker that has previously been demonstrated in small cell carcinomas of the skin (Merkel cell carcinomas), in 82 small cell carcinomas from a wide variety of sites (28 lung, 18 skin, 12 gastrointestinal tract, 8 sinonasal, 5 bladder, 3 prostate, 3 uterine cervix, 2 thyroid, 2 salivary gland, and 1 pancreas). Twenty-seven (96%) of the 28 SCLCs were positive for TTF-1. Among the nonpulmonary small cell carcinomas, two tumors of the gastrointestinal tract, one of the bladder, and one of the uterine cervix exhibited TTF-1 positivity. Sixteen (89%) of the 18 Merkel cell carcinomas and one SCLC were CK20-positive. All other small cell carcinomas were negative for this marker. These results indicate that although TTF-1 is not a specific marker for SCLC, it may assist in distinguishing SCLC from some nonpulmonary small cell carcinomas, particularly Merkel cell carcinoma, especially when it is used in conjunction with CK20.

Nasal-type T/NK lymphomas: a clinicopathologic study of 13 cases.

Natural Killer (NK) cell lymphomas, which include the nasal and the "nasal type" varieties, are defined as angiocentric lymphomas in the revised European American Lymphoma (R.E.A.L.) classification. This group of diseases is rare in the United States and Europe but is more common in Asia and Central America. It is associated with the Epstein-Barr virus (EBV) and its response to treatment and prognosis are usually very poor. The aim of this study was to describe our experience with 13 patients with angiocentric lymphomas seen at The University of Texas M. D. Anderson Cancer Center (UTMDACC) over the last 14 years. Thirteen patients with a diagnosis of nasal NK cell lymphoma were treated at UTMDACC from 1987 to 1999. Eleven patients were treated initially with doxorubicin based chemotherapy with or without radiotherapy. One patient received interferon (IFN)-alpha and vitamin A and another methotrexate, vincristine, L-Asparaginase, and radiotherapy. The median age was 44 years (range 15-76); there were four women and nine men. All patients presented with local disease involving the sinonasal region. Typical immunophenotypes expressing CD2+, CD3- and CD56+ surface markers as well as non rearrangement of T-receptors were present in all patients. Eight patients (62%) responded to therapy; six (46%) with complete response (CR) and two (16%) with partial response (PR). Five patients (38%) were alive, four with no evidence of disease (NED) at 1, 2, 3, and 9 years after treatment, and one patient was alive with disease (AWD) at the time of publication. One patient died while in CR from complications from allogeneic bone marrow transplant. Six patients had disease progression to extranodal sites including: testis (2), central nervous system (2), lung (1), bone marrow (2), liver (2), peripheral blood (2), and skin (2). In conclusion, the response to doxorubicin-containing regimens is inferior to that of patients with other non-Hodgkin's lymphomas and similar prognostic factors. Because the disease is associated with EBV virus in 90%-100% of the cases and the prognosis is poor, innovative therapies should be tried including immunotherapy that targets the expression of EBV by the tumor with or without myeloablative procedures.

Brenner tumor of the ovary: a comparative immunohistochemical and ultrastructural study with transitional cell carcinoma of the bladder.

Because of a fancied light microscopic resemblance to transitional epithelium (urothelium), Brenner tumor (BT) of the ovary is commonly described as a transitional cell neoplasm. An inability to detect a great deal of similarity between the two at the ultrastructural level prompted this electron microscopic study comparing 3 benign Brenner tumors with normal urothelium and 6 transitional cell carcinomas (TCC) of varying histologic grade from the urinary bladder. To complement the ultrastructural observations, the immunophenotype of 8 benign BTs was evaluated together with that of 12 TCCs of the bladder using antibodies to thrombomodulin (TM), cytokeratin 20, cytokeratin 7, and carcinoembryonic antigen (CEA), all of which have been shown to react with TCCs of urothelial origin. At the ultrastructural level, there was only limited evidence of a morphologic likeness between the epithelial cells of BTs and those of the benign or neoplastic urothelium. The immunophenotype of the two tumors also differed significantly in that there was no reactivity for TM or cytokeratin 20 in the BTs, while these markers were expressed in the TCCs. Both BTs and TCCs were positive for cytokeratin 7 and may express CEA.

Epithelial mesothelioma with deciduoid features: report of four cases.

Deciduoid mesothelioma is the designation given to an unusual morphologic variant of epithelial mesothelioma that closely simulates exuberant ectopic decidual reaction. Because all four previously reported cases involved the peritoneum and occurred in young women without a history of asbestos exposure, it was suggested that deciduoid mesothelioma was a subtype of epithelial mesothelioma characterized by its unique morphology, that it affects a distinct patient population, and that it is unrelated etiologically to asbestos. The author reports four cases of mesothelioma with deciduoid features, all of which originated in the pleura. Three of the patients were men and one was a woman. Their ages ranged from 46 to 78 years (mean age, 67 yrs). Two of the patients had a history of asbestos exposure. These findings indicate that this morphologic variant of mesothelioma is not limited to a specific patient population nor is it restricted to the peritoneum.

HER-2/neu gene amplification compared with HER-2/neu protein overexpression and interobserver reproducibility in invasive breast carcinoma.

We compared the detection of HER-2/neu gene amplification by fluorescence in situ hybridization (FISH) with detection of HER-2/neu protein overexpression by immunohistochemistry using 2 antibodies on 100 archival invasive breast carcinomas. Protein overexpression for each marker was scored independently by 4 pathologists using standardized criteria, and consensus was compared with results obtained from gene amplification. The concordance rate between FISH and immunohistochemistry was 76% for e2-4001 and 91% for the HercepTest. Of the 37 cases positive by e2-4001, 21 demonstrated no gene amplification; 7 of 24 cases positive by the HercepTest demonstrated no gene amplification. However, 1 of 61 cases negative by e2-4001 showed gene amplification; none of the cases negative by the HercepTest showed amplification. The predictive values of gene amplification based on 0-1+, 2+, and 3+ immunohistochemical staining were best for cases scored as 3+ (75% for e2-4001 and 89% for the HercepTest). Complete agreement among observers for immunohistochemical scoring of e2-4001 and the HercepTest was achieved in 75 and 85 cases, respectively. The pairwise kappa agreement values were substantial for e2-4001 and substantial to almost perfect for the HercepTest. Immunohistochemical staining may be considered a useful screening test. While negative staining almost always correlated with a lack of gene amplification, positive membranous staining, especially 2+, did not predict gene amplification. The low interobserver reproducibility in separating 2+ from 3+ cases necessitates further confirmation by FISH before treatment decisions are made.