Stereotactic breast biopsy of nonpalpable lesions: determinants of ductal carcinoma in situ underestimation rates.

PURPOSE: To measure the effect of biopsy device, probe size, mammographic lesion type, lesion size, and number of samples obtained per lesion on the ductal carcinoma in situ (DCIS) underestimation rate. MATERIALS AND METHODS: Nonpalpable breast lesions at 16 institutions received a histologic diagnosis of DCIS after 14-gauge automated large-core biopsy in 373 lesions and after 14- or 11-gauge directional vacuum-assisted biopsy in 953 lesions. The presence of histopathologic invasive carcinoma was noted at subsequent surgical biopsy. RESULTS: By performing the chi(2) test, independent significant DCIS underestimation rates by biopsy device were 20.4% (76 of 373) of lesions diagnosed at large-core biopsy and 11.2% (107 of 953) of lesions diagnosed at vacuum-assisted biopsy (P <.001); by lesion type, 24.3% (35 of 144) of masses and 12.5% (148 of 1,182) of microcalcifications (P <.001); and by number of specimens per lesion, 17.5% (88 of 502) with 10 or fewer specimens and 11.5% (92 of 799) with greater than 10 (P <.02). DCIS underestimations increased with lesion size. CONCLUSION: DCIS underestimations were 1.9 times more frequent with masses than with calcifications, 1.8 times more frequent with large-core biopsy than with vacuum-assisted biopsy, and 1.5 times more frequent with 10 or fewer specimens per lesion than with more than 10 specimens per lesion.

The acetabular teardrop and its relevance to acetabular migration.

Five pelvises were photographed, roentgenographed, and sequentially sectioned or reamed to determine the location and appearance of the acetabular teardrop figure. The teardrop is located inferomedially in the acetabulum, just superior to the obturator foramen. The lateral lip is the exterior, and the medial lip is the interior of the acetabular wall. The ilioischial line projects over the medial acetabulum only fortuitously on the straight anteroposterior (AP) roentgenogram. Because of parallax, the relationship between the ilioischial line and the teardrop changes for views varying as little as 10 degrees in horizontal obliquity from the true AP roentgenogram. Because the teardrop comprises a well-defined, constant portion of the medial acetabular wall whereas the ilioischial line does not, the authors recommend using the acetabular teardrop rather than the ilioischial line for the detection and measurement of medial and superior acetabular migration.

Three-dimensional computed tomography of the foot: optimizing the image.

The complex anatomy of the foot can be imaged using high resolution computed tomography. High resolution serial nonoverlapping CT scans of foot anatomy have a high degree of soft tissue contrast, and excellent geometrical accuracy (no magnification error). Three-dimensional surface reconstruction from CT scans of the foot were performed using specially developed computer software. These surface reconstructions display the osseous and soft tissue anatomy of the foot in a form similar to anatomic preparations. The removal of overlying skin, disarticulation of the ankle, tarsals and metatarsals was accomplished using computer methods. Major factors necessary to optimize three-dimensional images are presented and illustrated. The technique has been applied in living subjects with arthritis, carpal coalitions, osteochondritis dissecans, and fractures. These images have been useful in communicating the findings on high resolution CT scans to referring clinicians, correlating CT findings in areas of complex anatomy, and eliminating overlying or obscuring structures by mathematically disarticulating the foot and individual tarsal bones.

A comparative study of ependymomas by site of origin.

Sixty-one patients with histologically proven ependymoma were irradiated between 1954 and 1976. Supra-and infratentorial tumors occurred more often in children and spinal cord--cauda equina tumors more often in adults. Local control was achieved in four of 20 supratentorial, 13 of 26 infratentorial, three of seven intramedullary spinal cord, and seven of eight cauda equina tumors. Improved local control of infratentorial tumors was noted for patients who received higher biologically effective doses of radiation but no dose-response for supratentorial, spinal cord or cauda equina tumors could be found. Five-year actuarial survival was 56% for all patients, 35% for supratentorial, 59% for infratentorial, 57% for spinal cord and 83% for cauda equina tumors. Spinal metastases were pathologically documented in 5 of 46 (11%) patients with ependymomas above the foramen magnum. They were clinically evident in two patients and most common in patients with infratentorial tumors whose spines had not been irradiated. One patient who was irradiated externally for cauda equina tumor developed radiation myelopathy 1-1/2 years later; three of eight patients who received intrathecal gold 198 developed myelopathy and/or cauda equina syndrome 3-1/2 to 17 years later.