PubMed Health⌕ Search

Biomedical subjects

T M Wheeler

Publications and source records attributed to T M Wheeler.

At least 127 records · Page 7Linked to original sources
PubMed1991

The sonographic appearance of irradiated prostate cancer.

Transrectal ultrasonography of the prostate was performed before radical prostatectomy in 22 patients with persistent or recurrent cancer after definitive radiotherapy. Serial transverse sonograms were compared with whole-mount step-sections of the prostatectomy specimens to evaluate the sonographic features of irradiated prostate cancer. To define more clearly the effects of radiation on malignant prostatic tissue, we assessed the degree of histological change induced by the irradiation (radiation effects) as none, mild, moderate or severe. A total of 121 areas of cancer greater than 4 mm in maximum diameter were identified on the histological sections. Of these, 105 (87%) showed no radiation effects or mild effects, and 72% (76/105) of these appeared hypoechoic on the corresponding sonogram. There were 16 foci with moderate or severe radiation effects and only 25% (4/16) appeared hypoechoic. The remaining 12 foci were isoechoic. Areas of cancer which show moderate or severe radiation effects tend to become isoechoic while large (greater than 4 mm) foci of cancer in the irradiated prostate usually show little radiation effect, and these foci typically appear hypoechoic.

Aged↗
PubMed1991

Relationship between clinical stage and histological zone of origin in early prostate cancer: morphometric analysis.

A detailed morphometric analysis of 96 radical prostatectomy specimens (13 clinical stage A1, 29 A2, 34 B1 and 20 B2) was undertaken to examine the relationship of zone of origin to volume, grade and extraprostatic extension of cancer. In patients with stage A disease, transition zone (TZ) cancer (present in 81%) was significantly larger but of lower grade than peripheral zone (PZ) cancer (present in 90%). The total volume of cancer in stage A1 patients averaged 1.55 ml with 72% of TZ origin. In patients with stage A2 disease, tumour volume averaged 5.83 ml with only 57% of TZ origin. Specimens taken during transurethral resection of the prostate (TURP) revealed TZ cancer in 82% and PZ cancer either alone or with TZ cancer in 22%. The 9 patients with PZ cancer in the TURP specimen included 5 of the 11 with extracapsular extension and all 5 of those with seminal vesicle invasion. Every patient with stage B disease had PZ cancer which, in all except 3 cases, was of significantly larger volume and higher grade than any TZ cancer (present in 43%) in the same gland. In patients with stage B cancer, total tumour volume was 5.13 ml with 91% of PZ origin. TZ cancer tended to be well differentiated in all patients, even at large volumes, whereas PZ cancer was often moderately or poorly differentiated even at low volumes. In patients with stage B disease, TZ cancer appeared to be incidental and of no clinical importance, while in stage A patients PZ cancers were sometimes large, poorly differentiated and extended outside the prostate. Progression of a stage A cancer seems more likely to result from PZ cancer than TZ cancer, and the finding of PZ cancer in a TURP specimen should probably preclude its classification as stage A1.

Humans↗
PubMed1990

Thymic carcinoma. A clinicopathologic study of 13 cases.

Thymic carcinoma (TCA) is a thymic epithelial neoplasm with obvious cytologic atypia. We studied 13 cases of TCA by light microscopy, immunohistochemistry, and electron microscopy and correlated the findings with clinical features. The patients' mean age was 54.2 years (range 30-74); the male/female ratio was 7/6. Twelve of the 13 patients presented with signs and symptoms caused by compression of mediastinal organs; the other patient was asymptomatic. Paraneoplastic syndromes were never seen. At thoracotomy, 11 tumors invaded or adhered to surrounding structures; the other two were encapsulated. The histologic types include squamous carcinoma including the lymphoepithelioma-like subtype (seven cases), small cell carcinoma (four cases), clear cell carcinoma (one case), and adenosquamous carcinoma (one case). Positive immunoperoxidase studies were as follows: keratin (13 cases), epithelial membrane antigen (EMA) (13 cases), leukocyte common antigen (none), carcinoembryonic antigen (CEA) (five cases), B72.3 (seven cases), Leu 7 (two cases), human placental alkaline phosphatase (none), vimentin (none), and chromogranin (one case). This profile is similar to those of normal thymus and thymoma except for the absence of CEA, B72.3, EMA in normal thymus, and the absence of CEA and B72.3 in thymoma. Electron-microscopic studies performed on eight cases showed glandular and squamous differentiation in one adenosquamous carcinoma, squamous differentiation in five squamous carcinomas, and neuroendocrine differentiation in one small-cell carcinoma. Nine patients died (three due to postoperative complications and six due to recurrences or metastasis at 3-36 months). Four patients (all with squamous carcinoma) were alive without disease at 2-60 months. The clinical and pathologic features were comparable with those of approximately 62 other cases of TCA previously reported. There are a number of well-defined histologic types of TCA that allow the pathologist to make a differential diagnosis of TCA from tumors extending or metastatic to thymus or other primary mediastinal tumors. Although neither asymptomatic presentation nor encapsulation improves the poor prognosis of TCA, the squamous carcinoma subtype is associated with a better outcome than the other subtypes. Based on the electronmicroscopic and immunohistochemical findings, the presence of normal thymic tissue at the periphery of several tumors, and the observation that several TCA arose from preexisting thymomas or thymic cysts, we conclude that TCA is derived from thymic epithelium.

Adenocarcinoma↗
PubMed1989

The appearance of prostate cancer on transrectal ultrasonography: correlation of imaging and pathological examinations.

Preoperative transrectal ultrasonograms in 70 patients who underwent radical prostatectomy were compared retrospectively to the histological features of whole mount sections of the surgical specimens. In 42 cases (60 per cent) the tumor could be appreciated as a hypoechoic area on the sonogram. In only 1 case did the tumor appear as a hyperechoic area. In the other 27 cases (39 per cent) the tumor was isoechoic and could not be distinguished clearly from the surrounding tissue. The smallest tumor visualized sonographically measured 4.4 mm. in diameter in the surgical specimen. There was a statistically significant correlation among tumor echogenicity, the actual tumor size and the Gleason grade. Although there was a linear correlation between the size (maximum diameter) of the tumor measured by ultrasound and that determined from the histological sections, ultrasonography generally underestimated the size of the tumor, with the maximum diameter measured sonographically being approximately 4.8 mm. smaller than the diameter measured in the whole mount sections. Of 25 nonpalpable (stage A) tumors 9 (36 per cent) were visualized on ultrasound, while of 45 palpable (stage B) tumors 11 (21 per cent) were not. Although most clinically recognized tumors can be appreciated sonographically, the tumors that are visualized tend to be larger, less well differentiated and palpable. These features favor the use of sonography to stage and monitor established prostate cancers, and suggest that tumors detected by sonography in an early detection program are likely to be clinically important cancers.

Aged↗
PubMed1989

Pathologic basis of the sonographic appearance of the normal and malignant prostate.

The hypoechoic nature of prostatic cancer is now well recognized. In fact, not all cancers are purely hypoechoic; many are isoechoic, and some have a mixed echogenicity. Rarely, we have seen a cancer that was predominantly hyperechoic. Other signs of disturbance of the normal internal anatomy of the prostate may suggest the diagnosis of prostate cancer and are particularly valuable in assessing patients with more advanced disease. Approximately one third of early-stage cancers detected by palpation or transurethral resection are isoechoic. These tumors are anteriorly located, small, and well differentiated and infiltrate among normal glands or are composed of malignant glands similar in size to normal acini. Not all hypoechoic areas within the prostate are cancer; both normal anatomic structures and various benign conditions may appear less echogenic than the normal prostatic parenchyma. A comprehensive understanding of normal prostatic anatomy and the morphology of prostate cancer is essential to the accurate interpretation of the sonogram. Precise interpretation of prostatic sonograms requires detailed correlations of high-quality images with pathologic examinations of the whole prostate. The development of accurate criteria for the sonographic diagnosis of both malignant and benign prostatic diseases can be achieved only by such studies. As the possibilities and limitations of transrectal ultrasonography become apparent from pathologic correlation, the role of ultrasound in the diagnosis of prostate cancer will be placed on a more rational basis.

Diagnosis, Differential↗
PubMed1989

Staging of prostate cancer. Value of ultrasonography.

Clinical staging is the attempt to determine the pathologic extent of a cancer by clinical tests (Whitmore). Traditionally, staging of prostate cancer has relied on the digital rectal examination, but ultrasonography, which provides an unprecedented picture of the gland, has become a valuable adjunct. The overall sonographic pattern helps to classify a tumor as "localized" or "extensive." A more detailed analysis yields information about the volume and location of the primary tumor; the presence, location, and extent of extracapsular extension; and the presence of seminal vesicle invasion. Comparison of sonograms with corresponding sections of radical prostatectomy specimens demonstrates that ultrasound complements the digital examination in determining by clinical tests the pathologic extent of a cancer.

Humans↗
PubMed1989

Ultrasonographic changes in the normal and malignant prostate after definitive radiotherapy.

As treatments for early localized prostate cancer come under closer scrutiny, the fundamental problem of documenting the success of radiotherapy becomes more obvious. Currently, no satisfactory method exists to determine tumor viability after radiotherapy. Transrectal ultrasonography is particularly valuable for monitoring the response of prostate cancer to radiotherapy. Persistent cancer retains its hypoechoic appearance after definitive radiotherapy. Hypoechoic lesions greater than 5 mm in diameter found more than 12 months after radiotherapy should be suspected of representing persistent local disease. In our study, albeit in a selected group of patients undergoing salvage radical prostatectomy, 92 per cent of such findings were associated with what we interpreted as viable tumor by light microscopy. Ultrasound-guided biopsy should be considered in such circumstances. The persistence of hypoechoic lesions in more than 65 per cent of patients 12 to 36 months after radiotherapy also suggests that local treatment failure may be underestimated by digital rectal examination and random digitally guided biopsy. Serial measurement of the diameter of hypoechoic lesions may provide a valuable indicator of progress in an individual patient. Patients with enlarging foci of tumor within the prostate after radiotherapy might be selected for biopsy and further treatment. If such a policy is employed, it is likely that a higher incidence of persistent cancer will be found after radiotherapy than has previously been discovered by random digitally guided biopsy.

Humans↗
PubMed1989

Anatomic considerations in carcinoma of the prostate.

With new techniques for imaging the prostate--transrectal ultrasound, magnetic resonance, computed tomography scanning--careful correlation with pathologic specimens is crucial to establishing the accuracy of interpretation of the image. Serial sections of whole-mount specimens of the prostate removal at radical prostatectomy or autopsy are the gold standard by which any other method of pathologic correlation should be measured. More limited techniques of pathologic correlations, such as biopsy specimens, resulted in some confusion in the literature, particularly in reference to transrectal ultrasound. New techniques of immunohistochemistry, image analysis, flow cytometry, and molecular biology will undoubtedly augment our understanding of the origin, pathogenesis, and prognosis of prostate cancer.

Adenocarcinoma↗
PubMed1988

Testicular metastasis as the first manifestation of colon carcinoma.

Metastatic carcinoma to the testes is uncommon, and it is most often found incidentally at autopsy or after orchiectomy for prostatic carcinoma. One of the rarest causes of testicular tumor is metastasis from another primary site. It is even more unusual when the metastasis to the testicle is the first manifestation of the tumor. We report a case of asymptomatic colon carcinoma presenting as metastases to the testis and epididymis, which was diagnosed after biopsy of testicular nodules. Although nonlymphomatous cancer presenting as an intrascrotal mass is extremely rare, seldom detected clinically and almost never the first sign of disease, it should be considered a possibility, even in the young adult who presents with a mass involving the testicle or epididymis.

Adenocarcinoma↗
PubMed1988

Acquired cystic kidney disease: occurrence in patients on chronic peritoneal dialysis.

Acquired cystic kidney disease (ACKD) is a well-known complication of long-term hemodialysis. To the best of our knowledge, only six patients on continuous ambulatory peritoneal dialysis have been reported to develop this disease. We herein report two such cases, and concluded that the morphology of ACKD seems to be independent of the type of dialysis and that hemodialysis is not necessary for the development of ACKD.

Adult↗
PubMed1988

Thyroid cancer presenting as a hot thyroid nodule: report of a case and review of the literature.

We report a patient with a papillary carcinoma of the thyroid occurring within a hyperfunctioning adenoma. This patient underwent surgery on the basis of a positive fine-needle aspiration biopsy even though the 123I scan showed a hyperfunctioning nodule suppressing the rest of the gland. To avoid overlooking a thyroid carcinoma in a patient with a thyroid nodule, fine-needle aspiration biopsy should be performed routinely and a surgical procedure should be done when indicated by cytological data, regardless of scan findings.

Adenoma↗
PubMed1988

Local control of prostate cancer with radiotherapy: frequency and prognostic significance of positive results of postirradiation prostate biopsy.

The best available data indicate that, although it is imperfect, the postirradiation biopsy performed at a sufficient interval after radiotherapy can provide accurate prognostic information useful in the determination of the success or failure of radiotherapy in an individual patient as well as the measurement of overall efficacy of any particular radiotherapeutic regimen. Needle biopsy of the prostate was performed routinely in 510 patients with clinical stage A2, B, or C1 prostate cancer treated with a combination of radioactive gold seed implantation and external-beam irradiation. Of the 140 patients who had one or more needle biopsies performed 6-36 months after completion of radiotherapy, who had no evidence of local recurrence or distant metastases at the time of biopsy, and who had received no hormonal therapy before documented recurrence of the tumor, 45 (32%) had one or more biopsies positive for cancer. The frequency of positive biopsy results correlated significantly with the size of the local tumor but not with the grade. The correlation between biopsy results and the eventual development of recurrence was highly significant. If any biopsy was positive, 60% of the patients eventually developed local recurrence; if all biopsies were negative, only 19% developed local recurrence during the period of follow-up. The poor prognosis associated with a positive biopsy result was found within almost every subset of stage, grade, or nodal status examined although the results varied because of the small number of patients in some groups.

Biopsy, Needle↗
PubMed1986

The prognostic significance of post-irradiation biopsy results in patients with prostatic cancer.

To evaluate the prognostic significance of post-irradiation biopsy results in patients with prostatic cancer, we reviewed the records of 803 patients who had been treated with pelvic lymph node dissection, radioactive gold seed implantation and external beam irradiation. Of the patients 124 had 1 or more biopsies within 6 to 36 months after completion of radiotherapy when there was no evidence of local or distant recurrence of tumor. Patients were followed for a mean of 64 months (range 14 to 175 months) and received no other therapy before relapse. Over-all, 43 of these patients (35 per cent) had a positive biopsy result. The incidence of positive biopsy results correlated directly with the initial stage of the tumor, ranging from 22 per cent of stage B1N to 50 per cent of stage C1 lesions. However, biopsy results did not correlate with the grade of the tumor. Local recurrence and distant metastases were much more common among patients with a positive biopsy result (p equals 0.0006). Local recurrence developed in 58 per cent of the patients with a positive biopsy by 5 years and in 82 per cent by 10 years. Of those in whom all biopsies were negative only 18 per cent had local recurrence by 5 years and 32 per cent by 10 years. Biopsy results retained their prognostic significance even among the more favorable subset of patients whose pelvic lymph nodes were negative initially and those with a normal prostatic examination at biopsy. These results indicate that a post-irradiation prostate biopsy 6 to 36 months after completion of treatment can be used to determine the efficacy of a particular radiotherapeutic regimen as well as the success or failure of radiotherapy in an individual patient.

Aged↗
PubMed1986

Successful management of Histoplasma capsulatum infection of an abdominal aortic aneurysm.

A 65-year-old woman with disseminated histoplasmosis underwent resection of an atherosclerotic abdominal aortic aneurysm. Yeast forms of Histoplasma capsulatum were present in the aneurysm. Surgical resection and revascularization with a Dacron graft followed by systemic amphotericin B therapy and chronic ketoconazole suppressive therapy have resulted in a patient without symptoms 15 months postoperatively. It is important to be aware of the potential for artherosclerotic aortic aneurysm involvement by H. capsulatum.

Aged↗
PubMed1985

Prostatic biopsy after irradiation therapy for prostatic cancer.

To determine the prognostic significance of a routine needle biopsy of the prostate performed six to thirty-six months after the completion of definitive radiotherapy, biopsy results were analyzed in 146 patients who had no evidence of disease at the time of biopsy and who received no other therapy before proved recurrence of the tumor. Patients were followed up a mean of 3.9 years after radioactive gold seed implantation and external beam irradiation. The total dose was 8,000 rad. Among 146 patients, 56 (38%) had one or more positive biopsy results within this time interval. The positive biopsy rate correlated with the clinical stage ranging from 17 per cent in Stage B1N to 59 per cent in Stage C1. The risk of developing local recurrence or distant metastases at any given time after irradiation therapy was markedly greater in those patients with a positive biopsy result (p less than 0.0005). Prostatic biopsy is an accurate means of measuring the success of radiotherapy. A positive postirradiation biopsy result carries grave prognostic implications for the patient and indicates that the treatment has failed.

Actuarial Analysis↗
PubMed1984

The pathophysiology of neurofibromatosis. II. Angiosarcoma as a complication.

A patient with Von Recklinghausen neurofibromatosis and an angiosarcoma (which developed subsequent to two separate neurofibrosarcomas ) is described, and the association of neurofibromatosis and angiosarcoma is reviewed. The data showed that angiosarcoma is not coincidental with neurofibromatosis, and there is a need to focus investigative efforts on the vascular aspects of this disease.

Adult↗
PubMed1983

Intravascular papillary endothelial hyperplasia of the orbit and ocular adnexa. A report of five cases.

This is a clinicopathologic study of five patients with intravascular papillary endothelial hyperplasia involving the orbit and ocular adnexa. The median age of the patients was 45 years. Three lesions were located in the orbit, one in the eyelid, and one in the eyebrow. Four lesions were located within a distended vein and one involved an artery. The walls of the vessel corresponded to the "capsule" of the circumscribed mass. The lumen disclosed different stages of organization of a thrombus with prominent endothelial cell proliferation centered around cores of collagenous tissue and fibrin. Electron microscopy of one lesion displayed spindle-shaped cells with features of endothelial cells forming a polarized basement membrane with numerous micropinocytotic vesicles on their plasmalemma. Some cells showed ultrastructural features of pericytes. The lesion, which may be confused with angiosarcoma, represents an unusual exuberant proliferation of vascular endothelium as a cellular response to the organization of a thrombus.

Adult↗