Biomedical subjects
Publications and source records attributed to D S Hartman.
An overview of the various cystic neoplasms affecting the kidney is presented. Processes varying from a simple cyst to a cystic neoplasm will be reviewed discussing both their pathologic and imaging criteria.
The retroperitoneum is the space between the parietal peritoneum anteriorly and the transversalis fascia posteriorly. Most retroperitoneal tumors arise from mesenchyme, neurogenic tissue, or embryonic rests. By this definition and by including lymph nodes as a retroperitoneal organ, lymphoma is not considered a primary retroperitoneal tumor.
The authors retrospectively evaluated radiologic, clinical, and pathologic findings in 19 cases of lymphangioma of the retroperitoneum. The tumors were judged confined to one compartment of the retroperitoneum in 68% of the cases, whereas in 32% of cases the tumor involved more than one compartment. Abdominal radiography depicted the mass in all cases. Excretory urography demonstrated organ displacement without tumor invasion in all cases. Sonography showed multiloculated fluid in 61% of cases and a unicameral mass in 39% of cases. All but one of the multiloculated lymphangiomas had thick septa. Sonography also depicted the fluid as uncomplicated in 56% of cases. The remainder had debris that sometimes layered in the dependent portion of the cyst. Computed tomography (CT) showed a unicameral mass in 57% and a septated mass in 43% of cases. CT also showed thin, smooth walls in 79% and thick, irregular walls in 21% of cases. At CT the fluid contents were found to be homogeneous and of fluid attenuation in 64% and were complex in 36% of cases. The attenuation of fluid in one case was the same as that of retroperitoneal fat. In two cases the mass contained mural calcification. The most characteristic radiologic finding of lymphangioma of the retroperitoneum is an elongated tumor containing uncomplicated fluid with or without septa. Chyle and mural calcification are very uncommon in this location.
Explore the source record for details and available documents.
Paragangliomas of the retroperitoneum arise from specialized neural crest cells distributed along the aorta in association with the sympathetic chain. In order to ascertain characteristic CT features of extraadrenal retroperitoneal paragangliomas to differentiate them from other retroperitoneal tumors, 31 discrete tumors and two cases of paragangliomatosis in 28 patients were reviewed retrospectively, and the CT features were correlated with clinical and pathologic findings. There were 16 men and 12 women. Average age was 37 years (range, 11-70 years). Twenty-four patients (86%) had hypertension. Of these, catecholamine levels were elevated in all 18 patients who had biochemical studies. Four patients (14%) had malignant paragangliomas. The discrete tumors were classified by location as suprarenal (26%), renal hilar (32%), or infrarenal (42%). Suprarenal paragangliomas could not be distinguished from the ipsilateral adrenal gland on CT. The average size of functional tumors was smaller (7.0 cm) than that of nonfunctional tumors (12.0 cm), but the sizes of the two groups overlapped. Smaller tumors were more likely to be homogeneous and have well-defined margins than were larger tumors. Our findings indicate that extraadrenal retroperitoneal paragangliomas are functionally active more often than previously reported and that they are readily detected by CT as soft-tissue masses closely associated with the entire length of the abdominal aorta. However, no CT feature was found that was unique for paraganglioma.
1. Mouse fibroblast cell lines were established that stably express Torpedo californica acetylcholine receptors (AChR) on their cell surface in quantities sufficient for biochemical and pharmacological analyses, as well as electrophysiological analysis at the single channel level. 2. Surface-expressed AChRs were shown to be assembled into proper alpha 2 beta gamma delta pentamers. 3. The distribution of surface-AChRs was uniform and identical in every cell. 4. We were able to successfully coculture AChR-fibroblasts with 1-day old Xenopus laevis embryonal neurons and maintain expression of cell surface AChRs. 5. Using the voltage-clamp technique, miniature end-plate currents were recorded from AChR-fibroblasts which were contacted by neurons. The current amplitudes of these AChRs were approximately 10-fold smaller than those observed in Xenopus myocytes, and the rise-times were slower.
Torpedo californica acetylcholine receptor (AChR) alpha-, beta-, gamma-, and delta-subunit cDNAs were each stably introduced into muscle and/or fibroblast cell lines using recombinant retroviral vectors and viral infection, or using SV-40 vectors and DNA-mediated cotransfection. The expressed proteins were characterized in terms of their molecular mass, antigenicity, posttranslational processing, cell surface expression, stability in fibroblasts, stability in differentiated and undifferentiated muscle cells, and ability (of alpha) to bind alpha-bungarotoxin (BuTx). We demonstrated that the alpha, beta, gamma, and delta polypeptides acquired one, one, two, and three units of oligosaccharide, respectively. If all four subunits were expressed in the same cell, fully functional cell surface AChRs were produced which had a Kd for BuTx of 7.8 X 10(-11) M. In contrast, subunits expressed individually were not detected on the surface of fibroblasts and the Kd for BuTx binding to individual alpha polypeptides was only approximately 4 X 10(-7) M. The half-lives of the alpha, gamma, and delta subunits at 37 degrees C were all found to be quite short (approximately 43 min), while the half-life of the beta subunit was found to be even shorter (approximately 12 min). The unique half-life of the beta subunit suggests that it might perform a key regulatory role in the process of AChR subunit assembly. One stable fibroblast cell line was established by transfection that expressed beta, gamma, and delta subunits simultaneously. When this cell line was infected with a retroviral alpha recombinant, fully functional cell surface AChRs were produced. The successful expression of this pentameric protein complex combining transfection and infection techniques demonstrates one strategy for stably introducing the genes of a heterologous multisubunit protein complex into cells.
The authors retrospectively evaluated radiologic, clinical, and pathologic findings in 23 cases of mature teratoma arising within peri- or pararenal spaces. Radiologic studies--including abdominal radiographs (21 cases), excretory urograms (12 cases), sonograms (17 cases), and computed tomographic (CT) scans (18 cases)--were evaluated for tumor location, mass effect, calcification, fat, tumor invasion, echo pattern, and tissue characteristics. Most patients were female (3.4:1), younger than 6 months (50%), and asymptomatic. Abdominal radiography demonstrated a mass in 95%, calcium in 92%, and fat in 60% of cases in which CT revealed these components. Similarly, sonography showed uncomplicated fluid in 76% and calcium in 50% of cases. Fat was not reliably distinguished from other soft-tissue components on sonograms. The most characteristic radiologic findings of mature teratoma of the retroperitoneum are a complex mass containing a well-circumscribed fluid component of variable volume, adipose tissue and/or sebum in the form of a fat-fluid level, and calcification in either a congealed or linear strand pattern. These findings are better demonstrated by CT than by sonography.
The authors reviewed the prenatal (11 infants) and postnatal (17 infants) sonograms and the clinical, surgical, and pathologic findings in 17 infants with an ovarian cyst to determine the sonographic features and natural history of neonatal ovarian cysts. An uncomplicated cyst (nontwisted, nonhemorrhagic) was completely anechoic and the cyst wall was imperceptible with sonography (five cases). A twisted or hemorrhagic cyst was cystic with a fluid-debris level, cystic with a retracting clot, septated with or without internal echoes, or solid (12 cases). These complicated cysts contained liquid and/or organized hematoma. Eleven of the 12 complicated cysts had a thin, highly echogenic wall. Cyst torsion commonly occurred in utero and could be diagnosed on prenatal sonograms by a typical sonographic appearance (eight cases). All of these infants were asymptomatic after birth. Four infants with hemorrhagic or twisted cysts were symptomatic. All cysts except one that resolved spontaneously were treated surgically, including three twisted cysts that showed no change in size over a 1-8-month interval. All of the cysts were of follicular origin.
The CT and sonographic findings in 23 cases of renal lesions in which the abnormality was infiltrative, as opposed to expansile, were analyzed (invasive transitional cell carcinoma [seven], renal lymphoma [six], metastasis to the kidney [three], acute bacterial nephritis [three], mesoblastic nephroma [two], squamous cell carcinoma of the renal pelvis [one], and renal cell carcinoma [one]). CT scans were evaluated for shape and density of the mass, pelvocaliceal displacement, effect on the renal sinus fat, and the presence of perirenal involvement. Sonograms were evaluated for the shape and echogenicity of the mass and for the effect on the renal sinus echoes. Findings of infiltrative growth included poorly defined margins of the mass; trapped, nondisplaced infundibulae; and calices with occasional calicectasis, diminished contrast enhancement, occasional nephrographic striations, replacement of central sinus fat, loss of central sinus echoes, and variable renal parenchymal echogenicity. The reniform shape was usually preserved and was present in 19 of 20 cases with CT and 13 of 15 cases with sonograms. These observations indicate that analyses of the margins, architecture, and effects on the collecting system and renal sinus by the mass are helpful in the diagnosis of those diseases that characteristically infiltrate the kidney.
Foreign genes can be stably integrated into the genome of a cell by means of DNA-mediated gene transfer techniques, and large quantities of homogenous cells that continuously express these gene products can then be isolated. Such an expression system can be used to study the functional consequences of introducing specific mutations into genes and to study the expressed protein in the absence of cellular components with which it is normally in contact. All four Torpedo acetylcholine receptor (AChR) subunit complementary DNA's were introduced into the genome of a mouse fibroblast cell by DNA-mediated gene transfer. A clonal cell line that stably produced high concentrations of correctly assembled cell surface AChR's and formed proper ligand-gated ion channels was isolated. With this new expression system, recombinant DNA, biochemical, pharmacological, and electrophysiological techniques were combined to study Torpedo AChR's in a single intact system. The physiological and pharmacological profiles of Torpedo AChR's expressed in mouse fibroblast cells differ in some details from those described earlier, and may provide a more accurate reflection of the properties of this receptor in its natural environment.
1. Many diverse disease processes may result in a multiloculated renal mass. 2. The term "multilocular cyst" is purely descriptive and should not be used as a specific diagnosis. 3. The management of this diverse group of diseases is controversial. There is insufficient information concerning the accuracy of percutaneous biopsy to permit one to base management decisions on such a biopsy in most of these masses. The cystic diseases (septated cyst, localized cystic disease, segmental multicystic kidney) should be managed conservatively. Most cases of arteriovenous communication are readily diagnosed angiographically and managed by vascular occlusive techniques or by surgery. The remaining multiloculated renal masses usually require surgical removal for histologic diagnosis or definitive therapy or both.
Clinical histories and CT findings were reviewed in 38 patients with primary adrenocortical carcinomas. The primary tumors exhibited central areas of low attenuation representing tumor necrosis (n = 26), irregular contrast enhancement (n = 16), detectable calcification (n = 9), and a thin, capsulelike rim surrounding the tumor (n = 7). Tumors metastasized to liver (n = 9), lung (n = 5), and lymph nodes (n = 5). In eight of nine cases of liver metastasis the primary tumor arose in the left adrenal gland. Evidence of endocrinopathy was present in each of nine patients with lesions 6 cm or less in diameter, but in only two of seven adults with lesions exceeding 15 cm in diameter. We conclude that, contrary to established concepts, adrenocortical carcinoma may present as a smooth, homogeneous, functioning mass 6 cm or less in diameter on CT.
The sonograms of 26 patients (19 adults and seven children) with pathologically proven diagnoses of primary adrenocortical carcinoma were evaluated. Clinical corroboration was obtained in all cases. The size of the lesions ranged from 3 to 22 cm. The five smaller lesions (3-6 cm) showed a homogeneous echo pattern, similar to renal cortical echogenicity. The 21 larger lesions varied in echo texture, having a heterogeneous appearance with focal or scattered echopenic or echogenic zones representing areas of tumor necrosis, hemorrhage, and/or, rarely (19%), calcification. Even the largest lesions were fairly well delineated, often with a lobulated border. Few (7/26 or 27%) showed a surrounding echogenic thin capsulelike rim. All five small lesions showed clinical evidence of endocrine activity. Larger lesions were hormonally active less often (9/21 or 43%). Twelve patients (46%) showed no sign of endocrine activity and presented with symptoms such as fever, weight loss, abdominal discomfort, abdominal mass, hematuria, and hypertension. In the pediatric and adolescent age group (0-16 years), all tumors were hormonally active, while only seven (37%) of tumors in the adult population (17-69 years) were hormonally active. Unfortunately no echo pattern was characteristic enough to allow differentiation of adrenal adenoma from carcinoma. Smaller lesions are more likely to be benign, and larger lesions with areas of necrosis, hemorrhage, and calcification are more likely to be malignant.
Multicystic renal dysplasia in a crossed fused or nonfused ectopic kidney is a rare occurrence that produces unusual imaging findings. In four such cases in neonates, three presented with a palpable abdominal mass and one was discovered in utero with maternal sonography. In three cases, sonography showed a multicystic mass, contiguous with the lower pole of the orthotopic kidney. In the fourth infant, a crossed, tiny dysplastic kidney was not visualized, but its markedly dilated ectopic ureter was seen traversing the spine on CT. Ureteropelvic junction obstruction was present in the three fused orthotopic kidneys. The characteristic imaging findings of multicystic dysplasia and crossed renal ectopia include a multicystic mass of variable size that is contiguous with the lower pole of a hydronephrotic, malrotated kidney; ureteral displacement and/or dilatation; and contralateral absence of the kidney and its renal artery.
This case report illustrates the magnetic resonance imaging (MRI) appearance of a typically asymptomatic renal oncocytoma as a homogeneous mass of medium signal with a stellate central region of decreased signal, representing the central scar. The MRI was correlated with computed tomography (CT), ultrasound (US), and gross pathologic appearance. The appearance of a central scar is not specific for oncocytoma and does not exclude renal cell carcinoma, as illustrated by a second case.
Explore the source record for details and available documents.
Cystic renal cell carcinoma includes any malignant neoplasm of renal tubular epithelium which presents as a fluid-filled mass. Approximately 15 per cent of cases of renal cell carcinoma will be cystic on radiologic and pathologic examination. The clinical features of cystic renal cell carcinoma are similar to those which are solid. The radiographic and pathologic findings of cystic renal cell carcinoma are often more confusing and less specific than the findings of renal cell carcinoma which are predominantly solid. There are four basic pathologic mechanisms resulting in cystic renal cell carcinoma: intrinsic multiloculated growth; intrinsic unilocular growth (cystadenocarcinoma); cystic necrosis; and origin from the epithelial lining of a preexisting simple cyst. There are three basic radiologic patterns of cystic renal cell carcinoma: unilocular cystic mass, multiloculated cystic mass, and discrete mural nodule in a cystic mass. Cystic renal cell carcinoma is often extremely difficult to differentiate from non-neoplastic, benign neoplastic, and other malignant neoplastic masses utilizing radiologic studies alone. This review presents the clinical, pathologic, and radiographic features of cystic renal cell carcinoma and discusses its radiologic differential diagnosis.