The normal and abnormal growth plate

Skeletal growth is a dynamic process. A knowledge of the structure and function of the normal growth plate is essential in order to understand the pathophysiology of abnormal skeletal growth in various diseases. In this well-illustrated article, the authors provide a radiographic classification of abnormal growth plates and discuss mechanisms that lead to growth plate abnormalities.

Multiple skeletal fibroxanthomas: radiologic-pathologic correlation of 72 cases

Out of a series of 900 biopsy-proven cases of skeletal "fibroxanthoma" (nonossifying fibroma, fibrous cortical defect), we studied 72 patients with more than one lesion. Age, sex, coexistent conditions such as neurofibromatosis, and histologic and radiographic appearance of the lesions were evaluated. Multiple skeletal fibroxanthomas are probably more common than previously suspected. (At least 8% of the 900 patients in our archives had multiple lesions). Only a small percentage (5%) of patients with multiple skeletal fibroxanthomas had coexistent neurofibromatosis. These lesions are histologically indistinguishable from their solitary counterparts and most commonly present in the lower extremities. Four radiographic patterns were noted: clustered lesions--usually about the knee. nonclustered lesions--in opposite ends of long bones. coalescent lesions--several lesions coalescing over time. This observation has not been previously reported. emergent lesions--lesions appearing in previously unaffected bone. Familiarity with these features may obviate biopsy.

Paget disease of the anterior tibial tubercle

A study was done of 13 cases of biopsy-proved Paget disease in which the disease involved the anterior tibial tubercle with extension into the metaphysis and diaphysis, but without apparent involvement of the proximal tibial epiphysis. Case data were obtained from archives containing more than 350 cases of Paget disease. Age, sex, symptoms, serum alkaline phosphatase level, and histologic and radiographic appearance of the lesions were evaluated. Patients were young at clinical presentation, averaging 36 years of age. In five of six patients the serum alkaline phosphatase level was normal. The proximal extent of the disease was the anterior tibial tubercle rather than the proximal epiphysis. Radiographic patterns ranged from predominantly lytic to mixed lytic and blastic to predominantly blastic, and the lesion was marginated by a flame-shaped configuration. The radiographic appearance of Paget disease of the anterior tibial tubercle is characteristic and should be sufficient to suggest the diagnosis and preclude biopsy.

Effects of MR imaging on murine natural killer cell cytotoxicity

To determine the effect of MR imaging on the immune system, 21 male C57BL/6 X DBA/2 F1 mice were exposed to MR imaging at a field strength of 0.15 T for 2 hr. Another nine mice (controls) were sham exposed for the same amount of time. Mice were sacrificed and their spleens removed 24, 72, and 144 hr after the exposure (MR or sham). Spleen cell suspensions were passed over nylon wool columns and then used as effector cells in a short-term natural killer cell cytotoxicity assay with 51Cr-labeled YAC-1 cells as target cells. The results showed no evidence of decreased cytotoxicity due to exposure to MR. On the contrary, at all three times after exposure and for all target-to-effector cell ratios, mean cytotoxicity was greater for MR-exposed groups than for sham-exposed groups. The results show that MR exposure has no adverse effect on the immune system, as evidenced by natural killer cell activity.

Benign cortical defect: site for an avulsion fracture

A benign cortical defect in a bone may present itself as a weak site for muscle attachment resulting in an avulsion injury. Such a benign cortical defect may be mistaken for a malignant tumor when the avulsion injury excites irregular, laminated periosteal reaction. We report three patients in whom avulsion fractures occurred at the site of pre-existing benign cortical defects in the distal femur.

Benign fibrous histiocytoma: a rare endobronchial neoplasm

Fibrous histiocytomas are rarely found within the lung and have presented as a mass within a major airway only twice previously. This is the third reported case of such a tumor visualized roentgenographically in an airway on the frontal chest film of a patient presenting with recurrent pneumonia.

Radionuclide bone scanning in giant cell tumor

Radionuclide bone scan findings are described and correlated with pathology in 23 patients with giant cell tumor (GCT) of the bone. The degree of radionuclide activity was markedly increased in 20 (87%), minimally increased in three (13%), and decreased in none of the patients. Of the 23 patients with increased radioactivity, the pattern was diffuse in 11 (48%) and doughnut in 12 (52%). Extended patterns of radioactivity were present in 19 of 22 patients; however, none were associated with true tumor extension. Bone scanning did not aid in the detection of GCT, was nonspecific, and did not differentiate benign from malignant GCT. Although radioactivity extended beyond the radiographic abnormality in the majority of patients, this was most likely secondary to other bony abnormalities or local and/or regional hyperemia, and caution should be taken in ascribing this extension to either tumor or metastasis.

Cadaver radiography in the teaching of gross anatomy

The authors describe a new teaching method for first-year medical students, involving preparation and use of cadaver radiographs in the gross anatomy laboratory. A standard series of radiographs of each cadaver was obtained prior to dissection and provided to each group of students. This technique offers a unique opportunity for radiographic/anatomical/pathological correlation, facilitates an understanding of complex anatomical relationships, and illustrates the application of anatomical knowledge to clinical practice. It can also generate intense student enthusiasm and improve student-faculty communication and teaching relationships.

Multilocular cystic nephroma: a radiographic-pathologic correlation of 58 patients

Clinical radiographic, and pathologic findings of multilocular cystic nephroma (MLCN) in 58 patients are presented. The lesion that affects predominantly boys in childhood and women in adulthood is usually solitary but rarely can be multiple, and it commonly occurs as an asymptomatic mass, occasionally with hematuria. Tumors may grow slowly over years or rapidly within months. A mass that is usually identified on plain radiographs occasionally has curvilinear calcification. Excretory urography and retrograde pyelography are helpful when pelvic herniation of the tumor is recognized, or when septae are noted with total body opacification. Angiography showed an avascular mass (six lesions), a hypovascular mass (14 lesions), or a hypervascular mass three lesions). Ultrasonography is helpful when multiple circumscribed sonolucent areas are identified. Similarly, a multilocular mass with septae is usually identified by computed tomography (six of seven cases). Our findings and a review of the literature indicate that this lesion is a neoplasm that can be strongly suspected preoperatively if pelvic herniation or a multilocular pattern is noted on imaging studies.

Role of radiology in the study and identification of casualty victims

Radiology is assuming an increasingly important role in the investigation of casualty victims. Radiographic screening for foreign bodies, personal effects, dental and surgical artifacts and occult skeletal injury has long been an established technique in forensic medicine. Positive radiographic identification of the victims by comparison with antemortem films and records is a more recent, important development. Large scale radiographic investigations may require improvised facilities posing unaccustomed technical and logistical problems. Radiologic experience gained from aviation accident investigation is found to apply in other casualty situations as well as in individual fatality investigations. Radiologic data may aid determination of the cause of incidents, resulting in improved safety procedures and design, as well as serving humanitarian and forensic functions.

Primary malignant renal tumors in the second decade of life: Wilms tumor versus renal cell carcinoma

Primary renal malignancies occur least frequently in the second decade of life. Of the 4,798 cases of renal cell carcinoma and Wilms tumor referred to the Armed Forces Institute of Pathology 53 renal cell carcinomas and 56 Wilms tumors occurred in the 10 to 20-year age group. Pathologically, both tumors in this age range are similar to those occurring at a more typical age, and histologic differentiation between renal cell carcinoma and Wilms tumor is seldom a problem. While radiographic evaluation is useful to characterize the neoplasm, evaluate the contralateral kidney and detect the presence of tumor extension, current imaging techniques cannot confidently distinguish these 2 tumors.

Paget disease of the hand: radiographic spectrum

Paget disease uncommonly affects the hand. When it does, radiographic findings are same as when the disease occurs elsewhere. Eleven new cases that demonstrate four predominant radiographic patterns are described: homogeneous sclerosis, trabecular coarsening, cortical thickening, and lysis. The homogeneous sclerosis pattern was associated with monostotic hand disease. One patient developed bilateral phalangeal osteosarcomas. In every case, the disease process extended to the subarticular region and the affected bone was enlarged. With one exception, both ends of the bone were involved.

Radiologic and pathologic analysis of solitary bone lesions. Part I: internal margins

The interface between tumor and bone that is displayed radiographically is a zone of cellular activity. Its radiographic appearance represents the summation of bone lysis and production. This activity and the radiographic details of the resultant margin are an index of the biologic activity of a lesion. The anatomic site and extent of the lesion can be assessed by radiographs and special imaging techniques. Careful analysis of these patterns, when integrated with clinical data, enhances diagnosis, patient management, and therapy.

Radiologic and pathologic analysis of solitary bone lesions. Part II: periosteal reactions

The activated periosteum has a deceptive anatomic constancy amidst change. The change involves the production of matrix and, in the process, proliferation and expenditure of cells. When the demand for a reaction is excessive, nearby extraperiosteal soft tissue serves as a ready source for additional modulating cells, just as it does for fracture callus. The configuration of a periosteal reaction is an index of the nature and intensity of the inciting process.

Radiologic and pathologic analysis of solitary bone lesions. Part III: matrix patterns

The mineralized matrix patterns demonstrated in clinical radiographs of primary bone neoplasms and related disorders help to predict matrices, and have diagnostic significance. These radiographic patterns may yield important clues as to the true nature of a lesion, especially when only limited biopsy material is available from extraosseous or nonrepresentative areas. Therefore, in the evaluation of bone tumors and tumor-like conditions, it is of extreme importance to correlate the histologic findings with the radiographic examination and to know precisely the location at which the biopsy material was obtained. Patterns of mineralization may be the only remnants of a pre-existing lesion that has undergone sarcomatous transformation, such as in bone infarcts, enchondromas, or osteochondromas. The pre-eminent item of importance for patient care is the diagnosis of a malignant process. However, failure to appreciate antecedent benign conditions will not contribute toward a better understanding of tumor biology or a determination of those benign lesions that warrant removal or close clinical follow-up. Integration of matrix data with knowledge of the anatomic location of a lesion, the character of its margins, and the periosteal reaction patterns it produces permits prognostication and often, specific diagnosis.

Angiomyolipoma: computed tomographic-pathologic correlation of 17 cases

The angiomyolipoma is a benign renal tumor composed of fat, smooth muscle, and abnormal blood vessels. The tumor often extends into the perinephric space and often is complicated by intratumoral or perinephric hemorrhage. The CT findings of 17 cases of angiomyolipoma were correlated with their pathologic findings and are described. CT scans usually demonstrate a large fatty mass intermixed with areas of tissue density which may represent nonfatty parts of the tumor or areas of hemorrhage. CT is more sensitive than plain films at detecting the fat within the angiomyolipoma. CT is also useful in identifying perinephric extension and hemorrhage. In those angiomyolipomas composed primarily of smooth muscle or in which intratumoral hemorrhage has obscured the fatty part of the tumor, the CT appearance is indistinguishable from other solid renal tumors.

Angiomyolipoma: ultrasonic-pathologic correlation

Previous reports of angiomyolipoma have emphasized the ultrasonic finding of a very echogenic intrarenal mass. Ten cases of angiomyolipoma for which ultrasound examinations were available were retrospectively reviewed and correlated with their pathologic findings, and, when available, with computed tomographic findings to determine if other sonographic patterns could be recognized. In addition to the typical echodense pattern (six cases), a mixed pattern (two cases) and a low sonodense pattern (two cases) were discovered. To determine if the typical echodense pattern is specific for angiomyolipoma, 42 cases of renal cell carcinoma for which ultrasound examinations were available were also retrospectively reviewed. In two cases of renal cell carcinoma echodense patterns that were indistinguishable from those of angiomyolipoma were found. Two conclusions are reached: (a) there is a spectrum of ultrasonic findings with angiomyolipoma, and (b) the presence of an echodense intrarenal mass, although very suggestive of angiomyolipoma, is not pathognomonic.

Mesoblastic nephroma: radiologic-pathologic correlation of 20 cases

The mesoblastic nephroma is a benign renal tumor that usually appears as a neonatal abdominal mass. The tumor is composed of connective tissue that grows between nephrons and usually replaces most of the renal parenchyma. Radiographic and sonographic images reflect this cellular composition and unique growth pattern. The radiographs of 20 cases of mesoblastic nephroma were correlated with their pathologic findings and are described. Urograms usually demonstrate an intrarenal mass two to seven times larger than the contralateral kidney. Contrast medium is occasionally demonstrated within the tumor and may represent function by nephrons trapped within the mesoblastic nephroma. Sonographic studies correlate well with the gross morphology and may be useful in establishing the relation of the tumor to the kidney. Some neovascularity is present on angiographic examination and most tumors are hypervascular. Prognosis after complete excision is excellent and adjunctive therapy is unnecessary.

Role of radiology in aviation accident investigation

Radiographic screening of fatality victims for skeletal detail, dental and surgical artifacts, personal effects, and foreign bodies is of established value. Radiography as the primary means of positive victim identification, through comparison with antemortem films and records, is an important new role. Data on sources of injury and relationships between victims and the crash environment may be derived from radiographic injury patterns and may be correlated with mechanisms of injury production. The result of such analysis is improved safety design. Such radiography poses unique technical and logistical problems, often involving temporary or remote facilities, which must be solved with consideration for privacy and safety. Advance planning is essential for maximum benefit from radiographic investigation.

Traumatic splenic cyst: radiologic-pathologic correlation from the Armed Forces Institute of Pathology

Traumatic splenic cyst is one of many diagnostic choices when a mass is found in the left upper quadrant. In the appropriate clinical setting, demonstration of an intrasplenic, unilocular, avascular, homogeneous, fluid-filled mass with a smooth, sharply marginated wall should suggest a splenic cyst. On pathological examination, an epithelial lining implies a developmental origin. More commonly, no such lining is found and old trauma is assumed to be the etiology.