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Biomedical subjects

R O Petersen

Publications and source records attributed to R O Petersen.

At least 19 recordsLinked to original sources

Leiomyosarcoma of the renal vein.

The preoperative diagnosis for primary leiomyosarcoma of the renal vein, an extremely rare tumor, is difficult. The tumor predominantly occurs in women and on the left side. Its natural history is toward distant metastases and a poor 5-year survival rate. Nephrectomy and en-bloc surgical resection remain the mainstay of therapy. We present three such cases and review the world literature.

Adult

Cytologic features of pulmonary malakoplakia related to Rhodococcus equi in an immunocompromised host.

Cytologic features are described in bronchial brushings of a large cavitary lung mass from an immunosuppressed patient who had undergone liver transplantation. Scattered histiocytes with abundant eosinophilic, vacuolated cytoplasm were noted in a background of bronchial cells. Within approximately one fourth of the histiocytes, targetoid intracytoplasmic inclusions were present, consistent with Michaelis-Gutmann bodies. They were diffusely positive by histo-chemical staining with von Kossa, Gomori methenamine silver, and periodic acid-Schiff stains, and focally positive with Prussian blue stain. Cultures of the abscess yielded Rhodococcus equi. The characteristic microscopic features of pulmonary malakoplakia can be discerned in bronchial brushings, and should be sought, particularly in immunocompromised patients.

Cytodiagnosis

Induction androgen deprivation plus prostatectomy for stage T3 disease: failure to achieve prostate-specific antigen-based freedom from disease status in a phase II trial.

OBJECTIVES: There is interest in treating prostate cancer with induction androgen deprivation prior to radical prostatectomy. Data on long-term prostate-specific antigen (PSA)-based survival analyses among patients treated with neoadjuvant hormonal therapy (NHT) and prostatectomy are limited. In 1991 we instituted a pilot study for T3 disease based on endorectal coil magnetic resonance imaging (eMRI), mandatory negative laparoscopic nodal dissection prior to hormonal manipulation, and prostatectomy followed by pathologic and PSA-based outcome determinations. METHODS: Of 26 patients, 21 had negative laparoscopic lymphadenectomy followed by 4 months of NHT (leuprolide +/- flutamide) prior to radical prostatectomy. eMRI was performed at the time of diagnosis and following hormonal treatment. Serum PSA was determined at 3-month intervals. Prostatectomy specimens were evaluated by 3-mm whole-mount step sections. RESULTS: Prior to prostatectomy, biochemical response was documented in all patients and downsizing was observed by eMRI in 57%. Pathologic downstaging to a lower stage (T2c or lower) was achieved in 48%. However, the actuarial 3-year freedom from biochemical relapse rate was only 24%. CONCLUSIONS: Using laparoscopy to exclude node-positive patients and 4 months of NHT appears to result in pathologic and initial biochemical evidence of regression. These factors have not translated into improved freedom from biochemical relapse among patients with Stage T3 disease treated with NHT and prostatectomy. Recent data strongly suggest a beneficial effect in patients with clinical T2 disease treated with NHT and radical prostatectomy. The NGT and radical prostatectomy approach appeared to offer no clear advantage when compared with PSA-based benchmarks achieved with conformal irradiation or NHT followed by external beam treatment among patients with clinical T3 disease.

Aged

Metanephric adenoma: histology, immunophenotype, cytogenetics, ultrastructure.

Metanephric adenoma is a rare renal neoplasm that is histologically and clinically unique. We found this neoplasm in a 54-year-old woman. This large, well-circumscribed, solid, tan tumor showed histologic similarity to developing metanephric tubular epithelium. It is composed of uniformly small epithelial cells forming tubules. Immunohistochemical evaluation showed that the tumor cells express proximal tubule marker URO-2 and wt1 gene protein product, commonly expressed in Wilms' tumors. Ultrastructurally, the epithelial cells were characterized by the presence of cilia on the luminal side and were resting on an abundant basement membrane. Cytogenetic analysis showed normal female karyotype. The unique features of metanephric adenoma should be clinically and pathologically recognized because of its invariably benign course.

Adenocarcinoma

Deoxyribonucleic acid flow cytometry of testicular Leydig cell tumors.

We analyzed by flow cytometry the deoxyribonucleic acid content of 13 paraffin embedded, formalin-fixed Leydig cell tumors of the testis. Of the tumors 10 were clinically benign (9 diploid and 1 aneuploid) and 3 were malignant (aneuploid). The benign aneuploid tumor showed moderate cellular atypia and a low mitotic count (less than 2 per 10 high power fields). Our study suggests that the majority of Leydig cell tumors are diploid and the less common malignant tumors are typically aneuploid, and that deoxyribonucleic acid flow cytometric findings can be useful as a prognostic indicator in these tumors.

Adult

Renal cell carcinoma in the presence of adult polycystic kidney disease.

A case of autosomal dominant polycystic kidney disease associated with widely metastatic renal cell carcinoma is reported. The patient had presented with pneumothorax, weight loss, leukocytosis, lytic bone lesions, and hypercalcemia. Despite intensive diagnostic search for a neoplasm, no firm evidence of malignancy was found. However, at the autopsy, widely metastatic, papillary renal cell carcinoma was found originating in the left kidney. Many metastases showed central necrosis mimicking small cysts.

Carcinoma, Renal Cell

Prostate carcinoma: assessment of diagnostic criteria for capsular penetration on endorectal coil MR images.

PURPOSE: To assess the accuracy of using several criteria to evaluate endorectal coil magnetic resonance (MR) images for penetration of the prostatic capsule. MATERIALS AND METHODS: Thirty patients with prostate carcinoma underwent MR imaging and prostatectomy. Specified sites of potential capsular penetration on MR images were blindly evaluated by three readers for six diagnostic criteria. These evaluations were compared with pathologic findings of capsular penetration and were analyzed by means of receiver operating characteristic (ROC) analysis. RESULTS: The area under the ROC curve (Az) for the readers' overall impression of capsular penetration varied from .72 to .77. Highest mean Az's were for the criteria of capsular thickening (.74) and nodular extracapsular tumor (.72), although the latter finding had poor sensitivity (15%). Interobserver variation was low for all findings. CONCLUSION: Sensitivity and specificity were generally low for the diagnostic criteria. The usefulness of endorectal coil MR imaging in staging prostate cancer may be limited by the lack of diagnostic signs that uniformly identify extracapsular penetration.

Humans

Renal capsular hemangioma.

We present a rare example of hemangioma of the renal capsule. This benign mesenchymal tumor can present diagnostic difficulties, since it can radiographically and macroscopically simulate more common tumors of the kidney, including renal cell carcinoma. If the diagnosis is made or suspected preoperatively or during surgery a more conservative surgical approach should be considered.

Adult

Heterotopic mucinous cystadenoma of the pancreas.

A 46-year-old female who had been experiencing severe diarrhea and marked weight loss underwent exploratory laparotomy because of a mass near the tail of the pancreas noted on CT scan. Pathologic examination revealed a mucinous cystadenoma of the pancreas occurring in heterotopic pancreatic tissue. This is the second reported case of mucinous cystadenoma occurring in heterotopic pancreatic tissue.

Abdominal Neoplasms

Benign adrenocortical masses: diagnosis with chemical shift MR imaging.

Benign adrenocortical masses often contain lipid; metastases and pheochromocytomas do not. Standard and lipid-sensitive (chemical shift) magnetic resonance (MR) images of the adrenal glands in 31 patients with 45 adrenal masses were reviewed to determine if simple visual analysis of these images would increase diagnostic specificity. Lipid was considered present if signal intensity of the adrenal mass relative to other tissues decreased on chemical shift images relative to comparable standard images. Both myelolipomas and 26 of 27 benign cortical masses displayed a loss of signal intensity on at least one chemical shift image; all 12 metastases, the three hemorrhages, and a cyst did not. Opposed-phase images were slightly more sensitive than fat-suppressed images in depicting lipid within benign cortical masses. All masses had higher signal intensity than that of the liver on standard T2-weighted MR images. Chemical shift MR imaging can demonstrate lipid within benign adrenocortical masses and thus increase specificity, potentially obviating biopsy and aggressive follow-up.

Adenoma

Malignant mesothelioma of the tunica vaginalis testis.

Malignant mesothelioma of the tunica vaginalis is an extremely rare tumor. Appropriate treatment consists of inquinal orchiectomy with close followup. Treatment of locally recurrent malignant mesothelioma of the tunica vaginalis has not been standardized. We recommend radical resection for the initial presentation of locally recurrent disease rather than saving surgical resection as salvage therapy after other treatment modalities have failed. We report case 37 of malignant mesothelioma of the tunica vaginalis and review the literature.

Abdominal Muscles

Cutaneous malakoplakia simulating relapsing malignant lymphoma.

This report describes the case of a 42-year-old man with malignant lymphoma, diffuse large non-cleaved cell type, who developed cutaneous malakoplakia in the left groin. The patient had widespread lymph node involvement, including a left inguinal mass which was clinically thought to represent recurrent lymphoma. The inguinal mass failed to regress after chemotherapy and irradiation, although lymphoma in other sites responded to chemotherapy. A skin biopsy of the area showed an ulcer and an abscess involving the dermis and subcutaneous tissue. Microscopically, a diffuse infiltrate of foamy histiocytes was seen with numerous intracellular and extracellular, round and laminated bodies. Some of these bodies had a "targetoid" appearance, stained strongly with von-Kossa's calcium stain and showed the typical appearance of Michaelis-Gutmann bodies by electron microscopy. Cultured monocytes from the peripheral blood of the patient showed ultrastructural features similar to their tissue counterparts, suggesting a systemic involvement of the monocyte macrophage lineage. This case represents an unusual presentation of malakoplakia of the skin associated with relapsing malignant lymphoma in a patient on immunosuppressive drugs.

Adult

Age-related changes in tissue levels of prostatic acid phosphatase and prostate specific antigen.

Immunoperoxidase localization of prostatic tissue antigens has become useful in identifying the prostate as the origin of metastatic disease. Much research has been aimed at investigating the presence of these antigens in the adult prostate gland in benign and neoplastic states. Few studies have been done to determine the presence of these markers before puberty. We studied the prostate gland of 42 children of varying ages to determine the presence of these antigens at all age ranges to puberty. Sequential sections of the prostate were cut for prostate specific antigen, prostatic acid phosphatase, and hematoxylin and eosin staining. The degree of immunoperoxidase stain was graded from 0 to 4. The results showed that staining levels of prostate specific antigen and prostatic acid phosphatase were high at birth, decreased by age 6 months, reappeared by age 10 years and increased to puberty. Thus, the levels of prostate specific antigen and prostatic acid phosphatase appear to follow the testosterone levels, suggesting a hormonal dependence.

Acid Phosphatase

Immunoperoxidase localization of prostatic antigens. Comparison of primary and metastatic sites.

Immunoperoxidase staining for prostate specific antigen (PSA) and prostatic acid phosphatase (PAP) help to identify patients with prostatic carcinoma presenting as metastatic disease from an occult primary source. To clarify further the reliability of these prostatic tissue antigens, we have examined the primary tumor and metastatic sites in 16 autopsy cases. Eleven of these had diffusely positive findings for PSA and PAP in the primary and all metastatic sites, and 1 case lacked both antigens in all locations. Four cases demonstrated variability between these antigens and among various sites. Prostatic primary lesions contained PAP and PSA in 13 (81%) and 12 (75%) cases, respectively. The most reliable metastatic sites were lymph nodes, seminal vesicles, lung, bone, and kidney; while liver, adrenal, and colorectal sites were less reliable. No relationship existed between serum PAP levels and tissue detectability of PAP. The use of both PAP and PSA increases the likelihood of properly identifying the prostate as the organ of origin of metastatic disease. In spite of the use of both markers, however, three primary lesions would have been misdiagnosed, and 1 case lacked both antigens in all metastatic sites as well. In poorly differentiated lesions, the lack of both antigens does not unequivocally eliminate the possibility of prostatic carcinoma.

Acid Phosphatase

Malignant mesenchymoma of the spermatic cord.

Sarcomas of the spermatic cord are rare, with only approximately 200 such tumors reported in the literature. Of those cases only 3 fit the definition of malignant mesenchymoma: a mesenchymal tumor with 2 or more malignant elements other than fibrosarcoma. We report the fourth such case treated by local excision alone. The patient was free of disease 6 years after treatment.

Chondrosarcoma