Ultrastructural Analysis of Urethral Polyps against the Background of Urogenital Infection.

We performed an electron microscopic study of samples of urethral polyps obtained from 90 women (mean age 52.5±4.9 years). According to PCR and culture studies, the most common infectious agent in patients with urethral polyps is U. urealyticum (100% cases). In 70% cases, this infectious agent was present as monoinfection, of these, clinically significant concentration (>106 CFU/ml) were found in 53.3% cases. In 30% cases, associations with C. trachomatis, T. vaginalis, and M. genitalium were found. We observed significant ultrastructural heterogeneity of the epithelial cells in urethral polyps, which manifested in a combination of hyperplastic and metaplastic changes and signs of cytodestruction. Detection of mycoplasma-like bodies in connective tissue mononuclear cells and viral particles in epithelial cells during ultrastructural study, including cases with negative PCR results, indicates the pathogenetic role of latent infection in the formation of urethral polyps.

Urethral stromal tumor with pacemaker cell phenotype.

Penile malignancies are rare in developed countries. The authors present a case of a penile urethral mesenchymal tumor occurring in a 51-year-old Caucasian male and displaying light microscopic, immunohistochemical, and ultrastructural features suggestive of a pacemaker cell type, combined with a lack of diagnostic features of any other established tumor category. The immunohistochemical profile was intensely positive for vimentin, PKC theta, and NSE and weakly positive to nonreactive for CD34 and smooth muscle actin, and entirely negative for CD117 (c-kit), S-100, and other markers. C-kit and PDGFRA gene analysis showed no mutations. Electron microscopy revealed tumor cells with plentiful cytoplasm and cytoplasmic processes/filopodia, both filled with intermediate filaments and occasional solitary focal densities. There were also prominent smooth endoplasmic reticulum cisternae, caveolae, neurosecretory granules, particularly concentrated in cytoplasmic processes, and synaptic-type structures. Poorly formed basal lamina, gap junctions, and intercellular collagen aggregates, consistent with skeinoid-type fibers, were also noted. Interstitial cells with potential pacemaker function have been recently described in the lower urinary tract, including the urethra, and this tumor may be related to this cellular phenotype.

Small cell carcinoma arising from the outer urethral orifice: a case report examined by histologic, ultrastructural and immunohistochemical methods.

A case of small cell carcinoma arising in the outer urethral orifice is presented. The resected tumor showed a proliferation of small round or fusiform neoplastic cells in the submucosa. Tumor cells were arranged in sheets or a trabecular manner and possessed markedly hyperchromatic nuclei with a high N:C ratio, closely resembling small cell carcinoma of the lung. Characteristically, pagetoid intraepithelial spreading could be identified. However, there was no evidence of in situ transitional cell carcinoma and adeno- or squamous cell carcinoma components anywhere. Ultrastructurally, each tumor cell contained only a few membrane-bound cored granules measuring 60-100 nm, which were compatible with neurosecretory granules, and desmosome-like intercellular attachments, but lacked aggregated microfilaments. By immunohistochemical examination, tumor cells were positive for epithelial markers, such as cytokeratin and epithelial membrane antigen, and neuron specific enolase, but negative for any other neuro-endocrine markers. Extensive systemic examination failed to show the primary site to be other than the outer urethral orifice. These findings indicate that the current tumor is a small cell carcinoma with neuro-endocrine differentiation arising from the outer urethral orifice.

[Ultrastructural study of the stromal component in urethral caruncle]. / Estudio ultraestructural del componente estromal en la carúncula uretral.

The stromal component of the urethral caruncle (UC) comprises a mixture of inflammatory, vascular, and fibrotic phenomena. Although mastocytes are cell elements known to appear in relation with chronic inflammation, there is no data in the literature explaining their significance in UCs or their ultrastructure relation with fibroblasts. We postulate that this special form of intercellular attachment could play a role in this condition's pathogenesis.

Leiomyoma exhibiting a marked granular change: granular cell leiomyoma versus granular cell schwannoma.

Granular change of leiomyoma or granular cell leiomyoma is rare and not well recognized. It may be confused with the common variety of granular cell tumor, which is currently regarded as being of schwannian origin. A case of granular cell leiomyoma in the periurethral region of a 40-year-old woman is reported. Microscopy indicated that the tumor consisted of polygonal or fusiform cells with coarse, granular eosinophilic cytoplasm. Immunohistochemically, the tumor cells were positive for desmin and actin, but negative for neuron-specific enolase and S-100 protein. Electron microscopy revealed myofilaments in the tumor cells, thus documenting the myogenic origin of the granular cells. The granules were ultrastructurally similar to those of granular cell schwannoma as described in the literature. It is likely that granular cell tumor arises from different tissues.

Diagnostic electron microscopy of male genital tract tumors.

As illustrated in this review, neoplasms of the male genital tract are markedly heterogenous, reflecting their complex embryologic derivation and histogenetic classification. Transmission electron microscopy has greatly increased our understanding of the structure of these tumors, and in doing so has greatly improved our light microscopy. Additionally, in a number of selected situations, TEM also provides important practical diagnostic information. Currently, light microscopy in conjunction with clinical information is the central tool of tumor taxonomy. However, TEM with histochemistry, immunohistology, analytic cytometry, and molecular biology provide practical and useful information in some situations. In all cases, the application of these techniques has greatly increased our overall understanding of tumor structure, pathobiology, and classification.

Glycogen-rich clear cell carcinoma of the urethra: an ultrastructural study.

A 49-year-old black woman developed a urethral glycogen-rich clear cell carcinoma. She was treated with anterior pelvic exenteration. The resected lymph nodes, vagina, uterine cervix, endometrium, ovaries, and urinary bladder were free of neoplasm. Histologically the neoplasm consisted of clear cells growing in sheets and occasional papillary structures. In some areas, hobnail cells were present. Ultrastructurally, the cells had apical caps, short microvilli, and complex cell bases, and contained abundant glycogen. These features were identified in one, but not the other of two previously reported cases. Because glycogen-rich clear cell carcinomas of the lower urinary tract do not resemble ultrastructurally mesonephric remnants or carcinomas known to arise from them, these glycogen-rich clear cell carcinomas should not be called "mesonephromas" as has been the practice.

Primary malignant melanoma of female urethra: report of a case and review of the literature.

We report herein one case of malignant melanoma with a survival period of more than four years, refer to its recent conception on histopathological and ultrastructural problems and its treatment, and review the literature.

Prostatic adenocarcinoma with endometrioid features. Clinical, pathologic, and ultrastructural findings.

Thirteen cases of prostatic adenocarcinoma with endometrioid features were reviewed. The patients were older men (49-81 years) presenting with symptoms of hematuria and urinary obstruction. Each of the tumors displayed exophytic growth into the prostatic urethra, with involvement of the verumontanum. The urethral orifices of the large (primary) prostatic ducts were uniformly involved, and coexistent invasive (acinar) adenocarcinoma was identified in 10 cases (77%). The tumors exhibited a complex glandular pattern strikingly similar to uterine endometrial carcinoma, with prominent papillary formation in six cases. All cases demonstrated intense cytoplasmic immunoreactivity for prostatic acid phosphatase and prostate-specific antigen in at least part of the tumor. Focal staining for carcinoembryonic antigen was seen in three cases. Five tumors examined ultrastructurally demonstrated typical features of prostatic adenocarcinoma. Follow-up information was available on all 13 patients (6-83 months). Seven patients died of metastatic tumor (9-70 months after diagnosis), and the other six patients exhibited recurrent local or metastatic tumor. The sites of metastases were identical to those seen with invasive "acinar" prostatic adenocarcinoma, including pelvic lymph nodes, bones, and lungs. Crude 5-year survival was 15%, with a mean survival of 37 months. Adjuvant therapy provided palliative relief for many patients, but did not appear to influence survival. These findings indicate that endometrioid carcinoma is a histologically distinct variant of prostatic adenocarcinoma, with a more aggressive clinical behavior than previously thought.

Clear-cell adenocarcinoma of the female urethra.

Malignant cells were found in the urine of a 54-year-old woman. The papillary tumor subsequently removed from the posterior wall of the urethra proved to be a clear-cell adenocarcinoma. The cytologic, histologic and ultrastructural features of this tumor were very similar to clear-cell adenocarcinomas arising in the female genital tract, suggesting a possible Müllerian origin of this neoplasm.

Nephrogenic adenoma in female urethra.

A case of a 66 years old female who had a nephrogenic adenoma recurring three times during a 6 months course of her illness is reported. With each recurrence, the lesion moved toward the urethral orifice, suggesting an intimate relationship between the recurrent process and physical stimuli to the mucosa. Electron microscopy revealed merely non-specific morphological features of epithelial cells in the lesion. There were no positive morphological clues in the lesion for supporting the lesion to resemble mesonephric and/or mesodermal tissue. The diagnostic term of tubular metaplasia for the lesion is preferable instead of nephrogenic adenoma.

Papillary adenomas of prostatic urethra with ultrastructural histogenetic considerations.

Benign urethral lesions are rather uncommon, and relatively few cases have been described in the literature. Malignant neoplasms, such as squamous and transitional cell carcinomas, occur more frequently. The latter usually present as papillary lesions. Specifically, papillary adenomas of the prostatic urethra are very unusual and rare lesions. They are usually seen in children but occasionally are found in the adult. Symptoms include urinary obstruction, infection, enuresis, sexual disturbances, or hematuria. Two cases of papillary adenomas are presented in this article. The lesion is important because it can be a source of significant hematuria, but can be cured easily at cystoscopy by local excision. This article describes the electron microscopic findings in two of these tumors, trying to elucidate their histogenesis and nature. No ultrastructural studies of these lesions have been reported previously.

Clear cell adenocarcinoma of the female urethra: clinical and ultrastructural study suggesting a unique neoplasm.

A case of clear cell adenocarcinoma arising in the female urethra is described. The tumor had a tubulocystic pattern and intracytoplasmic glycogen, resembling clear cell carcinomas that occur in the vagina and upper female genital tract. Ultrastructural study, however, showed abundant and elongated microvilli on the tumor cells, a feature not seen in clear cell carcinomas or other common forms of carcinoma arising in the female genital tract. Six other cases of similar tumors of the female urethra were found in medical literature, yet there was no example of this tumor in the bladder or male urethra. Clinical and ultrastructural observations suggest that clear cell carcinoma of the female urethra is a distinctive neoplasm. Abundant microvilli provide morphologic evidence supporting the possibility of origin from the mesonephros. Radical extirpative surgery with urinary diversion appears to be the treatment of choice.

Tumor of mesonephric origin in a diverticulum of the urethra. An ultrastructural study.

A case of a rare tumor arising in a diverticulum of the urethra was studied. Light microscopy revealed the typical structures of mesonephric tumor with obvious infiltration of the muscularis. Electron microscopic appearance indicated that the tumor cells were immature and not totally characteristic of any tissue of origin. Apart from appearances suggesting rapid growth, cellular inclusions of various appearance were found.

Transitional cell carcinoma in the domestic cat.

In 17 cases of transitional cell carcinoma in cats the most common site for primary neoplasia was the urinary bladder; metastasis was recorded in five of the cases. Nine of the cases have been reported previously; the eight additional carcinomas from the files of the New York State College of Veterinary Medicine were highly invasive and had a desmoplastic response. According to WHO guidelines they were classified as nonpapillary, infiltrating; papillary, infiltrating; and variants of transitional cell carcinoma.