Composite paraganglioma-ganglioneuroma of the urinary bladder: a rare neoplasm causing hemodynamic crisis at tumour resection.

A 64-year-old man presented with gross painless hematuria. Cystoscopy revealed a submucosal bladder neck mass covered by normal urothelium. During transurethral resection, the patient developed hemodynamic crisis including sinus bradycardia. Histopathologic examination revealed a primary bladder composite paraganglioma-ganglioneuroma (CPG). The patient underwent partial cystectomy and is symptom-free after one year. Bladder CPGs are extremely rare neoplasms that may result in life-threatening catecholamine secretion, especially during tumour manipulation. These tumours require complete surgical excision and should be included in the differential diagnosis of any solitary bladder mass covered by normal urothelium, especially when there is a history of hypertension or micturition attacks.

Complex mucinous cystadenoma of undetermined malignant potential of the urachus.

Urachal mucinous neoplasms are rare and include both villous adenomas and invasive adenocarcinomas. These mucinous tumours should be completely excised as they can demonstrate aggressive clinical behaviour, including the development of pseudomyxoma peritonei. We describe a 70-year-old woman who presented with a lower abdominal mass and received a diagnosis of a rare, complex urachal mucinous cystadenoma of undetermined malignant potential. This tumour demonstrated extensive mucin extravasation into perivesical soft tissue, but was not associated with pseudomyxoma peritonei or any malignancy. Rarely described in the English literature, mucinous cystadenomas of the urachus should be treated similarly to their villous adenoma counterparts: with complete surgical excision to prevent local tumour recurrences.

In situ hybridization for the differentiation of Actinomyces and Nocardia in tissue sections.

The specific identification of filamentous bacteria in tissue sections can be difficult. The filamentous bacteria Actinomyces and Nocardia often produce similar host responses and single bacterial organisms seem morphologically similar; however, their differentiation may be clinically significant. In situ hybridization (ISH) may assist in the rapid and accurate identification of these microorganisms. In this study, DNA probes were directed against the variable regions of 16S ribosomal RNA genes of multiple Actinomyces and Nocardia spp. Probes were tested on 26 formalin-fixed, paraffin-embedded tissue specimens, each of which contained diagnostic foci of filamentous bacteria confirmed by both Gram and Grocott methenamine silver stains. On the basis of histology and clinical features, cases were classified as Actinomyces-related, n = 13 with 6 culture-proven cases and Nocardia-related, n = 13 with 11 culture-proven cases. Using this classification, all cases were assessed for cross-reactivity using other species-specific probes and probe specificity was determined. Overall, Gram and Grocott methenamine silver histochemical stains (100% sensitivity) were more sensitive than ISH (77% sensitivity for both Actinomyces and Nocardia probes). The slender caliber of filamentous bacteria was a limitation for ISH interpretation and necessitated careful examination of some slides. Probes demonstrated 100% specificity for identifying both species, 100% positive predictive value and 81% negative predictive value. No mixed infections were observed. This study demonstrates that ISH is highly specific for distinguishing between Actinomyces and Nocardia spp. in tissue sections. Although histochemical stains demonstrate greater sensitivity for organism detection, ISH is a rapid and specific technique that is especially useful for evaluating culture-negative or clinically unsuspected cases of filamentous bacterial infection.

Primary basaloid carcinoma of the nipple with associated squamous cell carcinoma in situ.

Basaloid carcinomas have been documented in various anatomic locations. We describe a primary invasive adenocarcinoma of the nipple with extensive basaloid features that was also associated with squamous cell carcinoma (SCC) in situ and an aggressive behavior. A 69-year-old woman without a history of breast neoplasia presented with right nipple pain. Biopsy of the nipple revealed SCC in situ. One year later, she returned with nipple ulceration. An excisional specimen showed a 1.7 cm nodule composed of invasive sheets and ribbons of basaloid cells with numerous mitoses, extensive tumor necrosis and evidence of glandular differentiation. SCC in situ was present in the overlying epidermis. The differential diagnosis included a primary basaloid adenocarcinoma of the nipple, basal cell carcinoma of the nipple, neuroendocrine carcinoma, melanoma, basaloid variant of adenoid cystic carcinoma and metastatic disease. Immunohistochemical profile of this tumor supported a primary basaloid adenocarcinoma of the nipple. Although the initial sentinel lymph node biopsy was negative, within a year of diagnosis, the patient developed ipsilateral axillary node and pulmonary metastases. To the best of our knowledge, this is the first case of basaloid carcinoma to be documented in this anatomic site.

Primary cardiac diffuse large B cell lymphoma presenting with superior vena cava syndrome.

Primary cardiac lymphomas are rare extranodal lymphomas that should be distinguished from secondary cardiac involvement by disseminated non-Hodgkin's lymphoma. Cardiac lymphomas often mimic other cardiac neoplasms, including myxomas and angiosarcomas, and often require multimodality cardiac imaging, in combination with endomyocardial biopsy, excisional biopsy or pericardial fluid cytology, to establish a definitive diagnosis. A 60-year-old immunocompetent man who presented with superior vena cava syndrome secondary to a right atrial, primary cardiac diffuse large B cell lymphoma (non-Hodgkin's lymphoma) is described in the present article. The patient had no clinical evidence of disseminated lymphoma and was successfully treated with prompt surgical excision of his atrial mass, followed by anthracycline-based chemotherapy. The patient required multi-modality cardiac imaging to accurately identify and plan surgical excision of his cardiac lymphoma. The therapeutic management and clinical and radio-logical features of primary cardiac lymphoma are reviewed.

Synchronous ipsilateral renal cell carcinoma and urothelial carcinoma of the renal pelvis.

Renal cell carcinoma (RCC) and urothelial carcinoma of the upper urinary tract are not uncommon urological malignancies. Their simultaneous occurrence in a patient is, however, extraordinarily rare. We report the case of a patient who underwent laparoscopic nephrectomy for suspected RCC. Preoperative imaging was suspicious for renal pelvic involvement, which was confirmed upon bivalving the fresh specimen at the time of surgery, with the discovery of a separate urothelium-based lesion. We discuss this rare occurrence and our management approach.

Extraskeletal Ewing's sarcoma/primitive neuroectodermal tumor of the posterior mediastinum with t(11;22)(q24;q12).

Ewing's sarcoma/primitive neuroectodermal tumor family of tumors is part of a rare group of malignant neoplasms with small round-cell morphology. We describe a 24-year-old woman who presented with non-specific back pain. A chest radiograph and magnetic resonance imaging demonstrated an extraosseous, dumbbell-shaped mass of the posterior mediastinum with extension into the spinal canal. The patient underwent a left posterolateral thoracotomy and a T3-5 laminectomy with subsequent multi-agent chemotherapy. Histopathologic examination of the tumor demonstrated sheets of primitive small round malignant cells that showed no visible differentiation. Neoplastic cells were strongly immunoreactive for CD99 and vimentin and were negative for chromogranin, synaptophysin, CD31, CD34, calcitonin, desmin, low-molecular weight cytokeratins, wide-spectrum cytokeratins, leukocyte common antigen, S-100 protein, and thyroid transcription factor-1. The neoplasm was diagnosed as a Ewing's sarcoma/primitive neuroectodermal tumor, and cytogenetic studies confirmed a t(11;22)(q24;q12) chromosomal translocation and an associated trisomy of chromosome 2, supporting the histologic diagnosis. Extraskeletal Ewing's sarcoma/primitive neuroectodermal tumors are rare neoplasms that should be distinguished from other small round-cell tumors by morphology and ancillary laboratory techniques. Although rare, they need to be considered in the differential diagnosis of primary mediastinal tumors.

Increased incidence of differentiated thyroid carcinoma and detection of subclinical disease.

BACKGROUND: Recent reports from North America and Europe have documented an annual increase in the incidence of differentiated thyroid carcinoma. We sought to investigate the relation between rates of detection, tumour size, age and sex. METHODS: Using the Ontario Cancer Registry, we identified 7422 cases of differentiated thyroid carcinoma diagnosed from Jan. 1, 1990, to Dec. 31, 2001. We obtained pathology reports for a random 10% of the 7422 patients for each year of the study period. The sample represented all Cancer Care Ontario regions. We compared the size of the patients' tumours by year, sex and age. RESULTS: As expected, the incidence of differentiated thyroid carcinoma increased over the 12-year period. A significantly higher number of small (< or = 2 cm), nonpalpable tumours were resected in 2001 than in 1990 (p = 0.001). The incidence of tumours 2-4 cm in diameter remained stable. When we examined differences in tumour detection rates by age and sex, we observed a disproportionate increase in the number of small tumours detected among women and among patients older than 45 years. INTERPRETATION: Our findings suggest that more frequent use of medical imaging has led to an increased detection rate of small, subclinical tumours, which in turn accounts for the higher incidence of differentiated thyroid carcinoma. This suggests that we need to re-evaluate our understanding of the trends in thyroid cancer incidence.

Solitary fibrous tumor of the anterior mediastinum: a rare extrapleural neoplasm.

Solitary fibrous tumors are uncommon spindle cell neoplasms originally thought to be restricted to the pleura. We describe a 62-year-old woman who presented with stridor and an anterior mediastinal mass. At thoracotomy, a 10.5 x 6.5 x 5.5 cm, circumscribed, firm mediastinal mass demonstrated no direct cardiac or pulmonary involvement. The tumor consisted of spindle cells organized in a patternless pattern with collagenous stroma and hemangiopericytoma-like vessels. Spindle cells were immunoreactive for CD34, CD99, desmin, vimentin and bcl-2 protein and a diagnosis of mediastinal solitary fibrous tumor was confirmed. The differential diagnosis of mediastinal solitary fibrous tumors is extensive and includes spindle cell thymoma, sarcomatoid carcinoma, malignant mesothelioma, inflammatory myofibroblastic tumor, peripheral nerve sheath tumors and various sarcomas. Despite their rarity in the mediastinum, solitary fibrous tumors can be recognized by their classic patternless morphology and immunophenotypic pattern. Their accurate classification is important, as solitary fibrous tumors are intermediate (rarely metastasizing) neoplasms that require complete surgical excision and long-term clinical follow-up for optimum therapy.

Mediastinal thymolipoma: a rare occurrence with striated myoid cells.

We describe a 49-year-old man who presented to hospital with unstable angina and who underwent emergency coronary artery bypass grafting. During the surgical procedure, an incidental anterior mediastinal mass was discovered. Histological examination of this mediastinal mass revealed a thymolipoma containing numerous polygonal, striated myoid cells that were immunoreactive for desmin, muscle-specific actin and myoglobin. Electron microscopy demonstrated numerous Z band structures confirming myoid differentiation. Even though the appearance of myoid cells in thymolipoma may be alarming, this tumor should be recognized as a benign entity. Thymolipomas containing striated myoid cells should be differentiated from more ominous thymic neoplasms, including teratomas and thymic liposarcomas. To our knowledge, this is only the third reported case of thymolipoma containing striated myoid cells.

Multifocal penile epithelioid hemangioendothelioma masquerading as superficial penile vein thrombosis.

A 42-year-old man presented with a progressively painful mass of the penile shaft that clinically resembled superficial penile vein thrombosis. The patient's symptoms were refractory to conservative therapy, and surgical excision revealed multifocal penile epithelioid hemangioendothelioma. He had no evidence of metastatic disease and was well 1 year after excision. Vascular neoplasms should be included in the differential diagnosis of painful penile masses and penile thrombophlebitis. To our knowledge, this is only the second reported case of multifocal penile epithelioid hemangioendothelioma.

Surgical pathology of noninfectious ascending aortitis: a study of 45 cases with emphasis on an isolated variant.

BACKGROUND: Aortitis is emerging as an important cause of ascending aortic aneurysm in the elderly. Its features have not been described in a surgical population. DESIGN: Retrospective clinicopathologic review of 45 cases of active noninfectious aortitis among 513 consecutive ascending aortic resections (1985 to 1999). METHODS: Clinical data were collected from medical records. Histopathologic features were recorded during review of slides stained with hematoxylin-eosin and Verhoeff-van Gieson. Cases were categorized by predefined clinical criteria. Clinicopathologic features were compared among groups, with emphasis on unsuspected aortitis without systemic arteritis. RESULTS: The 2 largest groups were isolated aortitis (47%) and giant cell arteritis (31%). Other aortitis groups included Takayasu (14%), rheumatoid (4%), and unclassified (4%). Patients with isolated aortitis and giant cell arteritis were generally women (80%; mean age 73 y). All 6 with Takayasu arteritis were women (mean age 26). Although giant cell arteritis and isolated aortitis were histologically indistinguishable, their clinical courses differed substantially. Among 21 patients with isolated aortitis (2 treated with corticosteroids), only 10% later developed aortic aneurysms. In contrast, of 14 patients with giant cell arteritis (11 treated with corticosteroids), 21% subsequently developed aneurysms (P=0.09). CONCLUSIONS: Aortitis primarily affected women. Patients with isolated aortitis and giant cell arteritis were generally older than 50 years and, by definition, those with Takayasu arteritis were younger. In patients with isolated aortitis, outcomes were generally good, despite the absence of anti-inflammatory therapy. Accordingly, a conservative approach may be warranted for managing this subset of patients with aortitis.

Aspergillus fumigatus pacemaker lead endocarditis: a case report and review of the literature.

The diagnosis of fungal endocarditis requires a high index of clinical suspicion. Rarely, pacemaker implantation may be a risk factor for the development of fungal endocarditis. A 71-year-old man with a history of multiple transvenous pacemaker manipulations and fever of an uncertain source is described. A diagnosis of culture-negative pacemaker endocarditis was established only after repeat transthoracic echocardiography. Amphotericin B was instituted; however, the patient developed a cerebral infarct and died. Postmortem examination demonstrated Aspergillus fumigatus within a large pacemaker lead thrombus, tricuspid and aortic valve vegetations, and septic pulmonary and renal emboli. The present report describes the clinical and pathological features of a rare case of Aspergillus fumigatus pacemaker lead endocarditis and suggests that serial echocardiograms may be effective in the early detection of pacemaker lead vegetations. The diagnostic features and therapeutic management of pacemaker lead endocarditis are reviewed.

Detection of prostate cancer from RF ultrasound echo signals using fractal analysis.

In this paper we propose a new feature, average Higuchi dimension of RF time series (AHDRFT), for detection of prostate cancer using ultrasound data. The proposed feature is extracted from RF echo signals acquired from prostate tissue in an in vitro setting and is used in combination with texture features extracted from the corresponding B-scan images. In a novel approach towards RF data collection, we continuously recorded backscattered echoes from the prostate tissue to acquire time series of the RF signals. We also collected B-scan images and performed a detailed histopathologic analysis on the tissue. To compute AHDRFT, the Higuchi fractal dimensions of the RF time series were averaged over a region of interest. AHDRFT and texture features extracted from corresponding B-scan images were used to classify regions of interest, as small as 0.028 cm of the prostate tissue in cancerous and normal classes. We validated the results based on our histopathologic maps. A combination of image statistical moments and features extracted from co-occurrence matrices of the B-scan images resulted in classification accuracy of around 87%. When AHDRFT was added to the feature vectors, the classification accuracy was consistently over 95% with best results of over 99% accuracy. Our results show that the RF time series backscattered from prostate tissues contain information that can be used for detection of prostate cancer.

Epiglottic histoplasmosis presenting in a nonendemic region: a clinical mimic of laryngeal carcinoma.

Histoplasma capsulatum is a dimorphic fungus endemic to North America. Histoplasmosis is primarily an inhalation-acquired mycosis that is encountered rarely outside of endemic regions. In nonendemic regions, histoplasmosis may present a diagnostic challenge and both clinical and laboratory vigilance are required to accurately identify infection. Unusual clinical presentations with limited physical findings may compound the difficulty in diagnosis. We describe a 78-year-old retired soil science professor who presented with an eroded epiglottic mass secondary to disseminated histoplasmosis in a nonendemic region (Alberta). Clinically, this mass was thought to represent a primary laryngeal carcinoma, as no other buccal or oropharyngeal ulcers were identified. Histoplasmosis was confirmed by tissue biopsy and a positive immunodiffusion test for immunoglobulin G. Disseminated histoplasmosis is often associated with laryngeal and oropharyngeal disease; however, isolated epiglottic histoplasmosis is rare. Histoplasmosis should be included in the differential diagnosis of neoplasms and chronic ulcers of the upper aerodigestive tract.

Adenomatoid tumor of the adrenal gland: a clinicopathologic study of five cases and review of the literature.

We report the clinicopathologic, immunophenotypic, DNA ploidy, and MIB-1 proliferative findings of five adenomatoid tumors of the adrenal gland. All patients were male, and tumors were incidental radiologic, surgical, or autopsy findings. Mean patient age at diagnosis was 41 years (range 31-64 years). The tumors ranged from 1.2 to 3.5 cm (mean 2.8 cm; median 3.2 cm) in greatest dimension, and all originated within the adrenal gland. The tumors were composed of anastomosing variably sized tubules lined by epithelioid as well as flattened cells. Signet-ring-like cells were present in all cases. The previously described histologic patterns of adenomatoid tumor, adenoid, angiomatoid, cystic, and solid, were observed, and each tumor contained multiple histologic patterns. In three of five cases, there was extra-adrenal extension of tumor into periadrenal adipose tissue. All adenomatoid tumors infiltrated the adrenal cortex, and in four cases the adrenal medulla was involved. All tumors exhibited strong immunoreactivity for calretinin, cytokeratins AE1/AE3, and CAM 5.2, cytokeratin 7, and vimentin. Tumors showed weak and focal immunoreactivity for cytokeratin 5/cytokeratin 6 and were negative for CD15, CD31, CD34, cytokeratin 20, MOC31, and polyclonal carcinoembryonic antigen. Ploidy analysis using Feulgen-stained sections and image analysis showed that three tumors were diploid and two were tetraploid. Tumors exhibited low MIB-1 proliferative activity, ranging from 0.2% to 2.7% (mean 1.6%). In three cases with clinical follow-up, no recurrence or metastases occurred. Adrenal gland adenomatoid tumors are morphologically and immunophenotypically identical to adenomatoid tumors of the genital tract and appear benign.

Extragenital adenomatoid tumor of a mediastinal lymph node.

Adenomatoid tumors are benign neoplasms found predominantly in male and female genital tracts. Rare extragenital adenomatoid tumors have been discovered that involve serosal surfaces and nonmesothelial-lined organs such as adrenal glands. Since the discovery of adenomatoid tumors, their histogenetic origin has been debated. Many researchers support a mesothelial cell origin for adenomatoid tumors because these tumors characteristically express a mesothelial phenotype. Tumor derivation from primitive pluripotent mesenchymal cells and coelomic epithelium also has been suggested because of the anatomical distribution of the tumors. Despite their characteristic mesothelial phenotype and histological appearance, adenomatoid tumors have an extensive differential diagnosis that includes vascular neoplasms, malignant mesothelioma, germ cell tumors, and metastatic adenocarcinoma. Recognition of these tumors may be especially difficult when examined at frozen section and when adenomatoid tumors are encountered in rare extragenital sites. We describe an adenomatoid tumor of a mediastinal lymph node that was found incidentally during a redo Collis-Nissen gastroplasty. On frozen section examination, this tumor was misinterpreted as metastatic adenocarcinoma. The hematoxylin-eosin histological, immunohistochemical, and ultrastructural studies confirmed the mesothelial phenotype of this tumor. To our knowledge, this is the first description of a lymph node adenomatoid tumor.