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Biomedical subjects

R B Wuerker

Publications and source records attributed to R B Wuerker.

At least 19 recordsLinked to original sources
PubMed1994

Endoscopic ultrasound-guided fine needle aspiration of pancreatic carcinoma.

Endoscopic ultrasound (EUS) is reported to be the single best modality for visualizing small pancreatic carcinomas. Whereas tissue diagnosis by fine needle aspiration (FNA) can be performed with computed tomography (CT) or transabdominal ultrasound guidance, the diagnostic accuracy is limited by the ability of these modalities to visualize the lesion. Real time EUS-guided fine needle aspiration has recently been reported as a new diagnostic modality. The application of EUS-guided FNA in the diagnosis of small pancreatic carcinoma has not been reported. We present a case in which transduodenal EUS-guided FNA was successful in establishing a definitive tissue diagnosis of pancreatic carcinoma in a 1.6-cm lesion in the head of the pancreas. This case along with a review of the literature highlights the great potential of this new modality in the diagnosis of pancreatic carcinoma.

Adenocarcinoma↗
PubMed1993

Meningioma-like tumor of the skin. An ultrastructural and immunohistochemical study.

Three unusual cutaneous tumors are described along with ultrastructural and immunohistochemical studies. All lesions were asymptomatic red-brown papulonodules. Light microscopic examination revealed a whorled configuration of spindle-shaped cells, some concentrically arranged around blood vessels. Immunohistochemical panels exhibited positive staining only with antibody to vimentin and negative staining with antibodies against S-100 protein, muscle markers, cytokeratin, epithelial membrane antigen, Leu 7, type IV collagen, and factor XIIIa, ruling out obvious nevomelanocytic, nerve sheath, meningothelial, smooth muscle, and perithelial differentiation. Electron microscopic examination demonstrated cells producing poorly formed collagen fibrils, sparse collagen fibers, and possessing occasional ill-defined intercellular junctions between their elongated cell processes. This rare tumor is considered to be either an immature fibrohistiocytic or possibly a nerve sheath neoplasm with striking similarities to so-called canine hemangiopericytoma. Because the prominent whorled pattern was reminiscent of meningioma, the lesion was referred to as meningioma-like tumor of the skin.

Actins↗
PubMed1991

Cytologic detection of colorectal cancer after administration of oral lavage solution.

Whether malignant cells can be detected in the bowel movements induced by oral gut lavage solution administration was studied in patients with known colonic adenocarcinomas. The induced bowel movements were collected in 27 patients, nine of whom had cancer proven by anatomic pathologic examination. The cells present were recovered with a simple technique and stained by the Papanicolaou method. Malignant cells were identified in the stained preparations in all nine patients with cancer (100% sensitivity), and there were few false positives (94.5% specificity). The authors concluded that if additional studies with greater numbers of subjects confirm the reliability of this technique, a test may be developed that would be useful for either early detection or screening.

Adenocarcinoma↗
PubMed1988

Oral hairy leukoplakia: ultrastructural observations.

On the basis of the clinical appearance and the light microscopic findings, we determined 16 biopsy specimens to be possible examples of oral hairy leukoplakia. All 16 specimens were studied by means of electron microscopy. Ten of these specimens contained typical herpes-type viral particles in the epithelial cells of the upper stratum spinosum. None of the specimens contained ultrastructural evidence of human papillomaviruses.

Candida↗
PubMed1988

Oral hairy leukoplakia: a light microscopic and immunohistochemical study.

We compared the light microscopic features and immunoperoxidase staining for human papillomavirus antigen of oral hairy leukoplakia (OHL) and flat condylomatous lesions of the cervix. Our findings support the conclusion that OHL and flat condylomatous lesions of the cervix are not similar morphologically or etiologically. Therefore the term koilocyte seems inappropriate to describe the swollen epithelial cells in OHL. The various diagnostic criteria for a diagnosis of OHL were reviewed. On the basis of the review of our cases of OHL and our review of the literature, we conclude that a definitive diagnosis of OHL requires either the biochemical evidence of Epstein-Barr virus or the ultrastructural demonstration of herpesviruses in suspected lesions.

Antigens, Viral, Tumor↗
PubMed1987

Oral mucosal cytomegalovirus as a manifestation of the acquired immune deficiency syndrome.

Cytomegalovirus (CMV) infection presenting as a painful palatal gingival ulcer was one of the initial clinical manifestations of the acquired immune deficiency syndrome (AIDS) in a male homosexual patient. The diagnosis of oral CMV infection was established when large intranuclear and smaller cytoplasmic CMV inclusions were observed in endothelial cells at the base of the mucosal ulcer. The identification of intranuclear and intracytoplasmic herpes-type viral particles in the infected cells was confirmed by electron microscopy. Cytoplasmic viral particles coexisted with paranuclear dense bodies resembling lysosomes. These features are characteristic of CMV-infected cells. A review of the English-language literature disclosed only three previously reported cases of CMV infection involving the oral mucous membranes. A vasculitis associated with the CMV-infected endothelial cells appears to be the underlying mechanism responsible for development of the oral ulcer. CMV should be considered a possible causative agent when oral ulcers are detected in immunocompromised patients. Likewise, the finding of CMV in oral ulcers should alert one to the possibility of an immunocompromised state.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Cylindrical cell papilloma.

A case of cylindrical cell papilloma (CCP) arising in the maxillary sinus is described. Light and electron microscopic findings revealed the characteristic oncocytic nature of the neoplasm. A review of the literature confirms the rarity of CCP and its behavioral similarities to the more common inverted papilloma. The relatively high rate of recurrence, coupled with the increased risk of associated malignancy, necessitates the recognition and appropriate treatment of CCP.

Adenocarcinoma↗
PubMed1986

Relationship between changes in the histologic subtype of small cell carcinoma of the lung and the response to chemotherapy.

It has been documented that changes in the histopathologic subtype of small cell carcinoma of the lung (SCCL) may occur after chemotherapy. The significance of such changes with respect to response to treatment has not yet been studied. In a retrospective review of 25 patients, we correlated their response from chemotherapy with morphologic changes seen in subsequent histologic material. Eleven patients responded to therapy and 14 failed to respond. A difference in original histologic subtype was found in 10 (71%) of the nonresponders and in only two (18%) of the responders. The difference was statistically significant (p less than 0.05). We conclude that patients with "pure" SCCL in the initial biopsy specimen who fail to respond to chemotherapy are likely to have mixed or combined histologic subtypes in subsequent tissue specimens, although we cannot preclude their pre-existence. An attempt to search for different histologic subtypes is warranted in patients who do not respond to chemotherapy regimens considered to be efficacious in SCCL.

Aged↗
PubMed1984

The clinical significance of radiographically detected pulmonary neoplastic lesions in patients with head and neck cancer.

The histopathologic features of pulmonary lesions found in 36 patients with head and neck cancer ( HNC ) whose chest radiograms had abnormalities suggestive of a neoplasm were reviewed. Ten patients (28%) had benign lesions but cancer was diagnosed in 26 patients (72%) by lung biopsy or at autopsy. Second primary lung cancer was found in 19 (53%) and metastatic HNC in seven (19%) of the 36 patients examined. The second lung primaries occurred in seven (100%) patients with HNC in stage I or II and in 12 (63%) of those in stage III or IV. The histologic examination revealed squamous cell carcinoma of the lung in eight (42%) of 19 patients, small cell carcinoma in six (31.5%), adenocarcinoma in three (16%), and large-cell carcinoma in two (10.5%). These findings indicate that a prompt histologic examination of radiographically detected neoplastic pulmonary lesions in patients who have, or have had HNC is mandatory because a second primary cancer of the lung may be found and cured with early treatment. Furthermore, a substantial number of the patients in this retrospective analysis had small-cell carcinoma of the lung and could benefit from current therapeutic advances for this type of tumor.

Adenocarcinoma↗
PubMed1983

Prolonged survival of patients with extrapulmonary small cell carcinoma arising in the neck.

Two patients with extrapulmonary small cell carcinoma localized in the neck survived for more than two years without systemic therapy. This suggests that there may be a subset of small cell carcinomas characterized by slow growth, resulting in an indolent clinical course. By light and electron microscopy, we were unable to identify features of this indolent form which differ from those of the aggressive form of pulmonary or extrapulmonary small cell carcinoma.

Biopsy↗
PubMed1979

Epithelial islands associated with mandibular nerves. Report of two cases in the walls of mandibular cysts.

Epithelial islands in association with nerve fibers in the jaw bones have been reported previously. We describe two such cases and present evidence that the epithelial structures as observed in this study are odontogenic rests and not neuroepithelial organs. Regardless of origin, it should be recognized that these epithelial islands do not represent neural invasion by carcinoma.

Cytoplasm↗
PubMed1979

Ultrastructural examination of urinary sediment. Value in renal amyloidosis.

Examination of urinary sediment has been recommended as a useful diagnostic aid for renal amyloidosis. This procedure was evaluated in the cases of 57 patients, including 11 with proven renal amyloidosis and 13 considered very likely to have the disease. At least three types of urinary fibrillar material were observed: 10-12-nm-diameter fibrils similar to amyloid; 7-10-nm-diameter fibrils with characteristics of intracellular tonofibrils; and 15-30-nm-diameter fibrils suggestive of fibrin tendrils. Only four of 24 patients who had renal amyloidosis proven or suspected had amyloid-like fibrils in the urinary sediment, while four control patients, including three with diabetic nephropathy, had similar fibrils. Sixty-eight per cent of all urines contained material consistent with tonofibrils. Ultrastructural examination of urinary sediment as a diagnostic aid for renal amyloidosis lacks sensitivity and specificity and has very limited clinical value.

Amyloid↗
PubMed1977

Ultrastructure of atypical fibroxanthoma.

Electron microscopic examination of an atypical fibroxanthoma (AFX) confirmed the fibrohistiocytic nature of this lesion. Ultrastructural evidence suggested a transition from fibroblasts to large giant cells with intermediate forms exhibiting features of both. A comparison of AFX ultrastructural features to those of other similar neoplasms suggested a possible relationship to malignant fibrous histiocytoma. As diagnosed by light microscopy, AFX probably represents a spectrum of neoplasms; this concept is discussed. It is urged, when possible, that electron microscopy be performed on lesions diagnosed as atypical fibroxanthoma since ultrastructure studies represent the most valid basis on which a correct diagnosis can be made.

Aged↗