Tropical Medicine Central Resource

Pelvis and Hip Joint

The pelvic girdle is a common site for the cyst wall and its laminated membrane to insinuate between the trabeculae and slowly spread within the cancellous bone, eventually eroding through the cortex into the surrounding soft tissues. Since the process may be asymptomatic for a long period, the initial radiographs usually show extensive destruction of bone (Figs. 3.132, 3.133, 3.134, 3.135), although a solitary cyst-like or "bubbly-cystic" lesion may be seen (Fig. 3.133A). There may be one enormous solitary cyst, but more often there are numerous smaller cysts scattered diffusely through the pelvis, giving the characteristic appearance of "clusters of grapes" (Figs. 3.132 and 3.133B). Since bony destruction proceeds at a slow rate, the skeleton can respond with the formation of dense reactive bone (Figs. 3.132C, 3.133, 3.134, 3.135). The resulting intermingling of large cystic spaces with coarse strands and islands of bone creates a bizarre appearance, which is often mistaken for a primary malignant bone tumor such as chondrosarcoma (Fig. 3.134).

Fig. 3.132 Hydatid cyst of the sacrum in a 52-year-old man from the Mediterranean area. (A) The initial AP view of the pelvis in July reveals an extensive lytic destructive lesion involving most of the sacrum associated with a multilocular cystic appearance and expansion. In addition to being compatible with a hydatid cyst, the radiographic appearance is also suggestive of giant cell tumor, cyst, angioma, or myeloma. At this time, the patient had pain in the left hip referred down the leg, with numbness of the foot and toes of 18 months' duration. In May he had noticed swelling of the left gluteal region. By the time of the July radiograph, the swelling had developed into a large fluctuant, painful abscess which was drained one day previously of two quarts of thick, purulent material. At surgery, the cortex of the dorsal surface of the sacrum was penetrated and curettings were obtained; these consisted of small globular masses of homogeneous, dull, yellowish material, some of which contained individual pinhead-sized, clear cysts. Microscopic study initially showed granulomatous inflammation with some giant cells, and a giant cell tumor was suggested. However, examination of further material revealed an Echinococcus cyst. (B) Lateral and (C) AP views of the sacrum taken three years later in October show the markedly expansile, bubbly cystic nature of the lesion, seen best on the lateral view (B). During this three year interval, there has been development of dense reactive bone surrounding and within the lesion, with coarse strands of dense bone particularly noticeable about the right upper and left lower wings of the sacrum. This represents attempted healing of the destructive process, which showed no further increase in extent in the three year interval. (Chemotherapy was not available when this patient was seen).

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Fig. 3.133 Hydatid disease of the pelvis presenting as bubbly cystic, expansile lesions with surrounding reactive sclerosis. (A) A solitary large multilocular cyst in the right iliac bone. There is expansion of the iliac crest with cortical breakthrough and a thin reactive layer of bone sclerosis about the lesion. (B) Bubbly cystic, expansile lesion involving the pubis, ischium, and acetabulum on both sides of the pelvis. Hydatid disease may cross the pubic symphysis, as in this case, or the sacroiliac or hip joints.

Fig. 3.134 Hydatid disease involving the right ilium and resembling chondrosarcoma. There is a diffuse multicystic type of bone destruction intermingled with irregular, coarse trabecular strands and islands of dense bone. The calcification, cortical destruction, and surrounding soft tissue mass produce an appearance that may be confused with chondrosarcoma. (Courtesy of Dr. Daniel Wilner: Radiological Diagnosis of Tumors in Bone and Allied Disorders, 1979).

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Fig. 3.135 Extreme destruction of pelvic bones by hydatid disease. There is gross osteolysis with expanded blowout lesions of bone involving the right hemipelvis in (A) and virtually the entire pelvis in (B). The radiographic appearance at this end stage shows a massive destructive process so bizarre that no identifiable osseous features remain. The lumbar vertebral column can be seen to the right of the large expansile lesion arising from the right iliac bone in (A). In (B) the upper sacrum with its spinous processes are barely discernible in the upper portion of the film. In both cases, there is little more than a shell of bone with reinforced trabecular strands and irregular calcifications in these grossly expansile, blowout lesions. Despite the vast loss of bone structure in such cases, the complicating osteitis with its dense reactive new bone formation tends to stabilize the process somewhat, although crippling deformities are obviously present.

		Pelvis and Hip Joint The pelvic girdle is a common site for the cyst wall and its laminated membrane to insinuate between the trabeculae and slowly spread within the cancellous bone, eventually eroding through the cortex into the surrounding soft tissues. Since the process may be asymptomatic for a long period, the initial radiographs usually show extensive destruction of bone (Figs. 3.132, 3.133, 3.134, 3.135), although a solitary cyst-like or "bubbly-cystic" lesion may be seen (Fig. 3.133A). There may be one enormous solitary cyst, but more often there are numerous smaller cysts scattered diffusely through the pelvis, giving the characteristic appearance of "clusters of grapes" (Figs. 3.132 and 3.133B). Since bony destruction proceeds at a slow rate, the skeleton can respond with the formation of dense reactive bone (Figs. 3.132C, 3.133, 3.134, 3.135). The resulting intermingling of large cystic spaces with coarse strands and islands of bone creates a bizarre appearance, which is often mistaken for a primary malignant bone tumor such as chondrosarcoma (Fig. 3.134). .. Fig. 3.132 Hydatid cyst of the sacrum in a 52-year-old man from the Mediterranean area. (A) The initial AP view of the pelvis in July reveals an extensive lytic destructive lesion involving most of the sacrum associated with a multilocular cystic appearance and expansion. In addition to being compatible with a hydatid cyst, the radiographic appearance is also suggestive of giant cell tumor, cyst, angioma, or myeloma. At this time, the patient had pain in the left hip referred down the leg, with numbness of the foot and toes of 18 months' duration. In May he had noticed swelling of the left gluteal region. By the time of the July radiograph, the swelling had developed into a large fluctuant, painful abscess which was drained one day previously of two quarts of thick, purulent material. At surgery, the cortex of the dorsal surface of the sacrum was penetrated and curettings were obtained; these consisted of small globular masses of homogeneous, dull, yellowish material, some of which contained individual pinhead-sized, clear cysts. Microscopic study initially showed granulomatous inflammation with some giant cells, and a giant cell tumor was suggested. However, examination of further material revealed an Echinococcus cyst. (B) Lateral and (C) AP views of the sacrum taken three years later in October show the markedly expansile, bubbly cystic nature of the lesion, seen best on the lateral view (B). During this three year interval, there has been development of dense reactive bone surrounding and within the lesion, with coarse strands of dense bone particularly noticeable about the right upper and left lower wings of the sacrum. This represents attempted healing of the destructive process, which showed no further increase in extent in the three year interval. (Chemotherapy was not available when this patient was seen). .... Fig. 3.133 Hydatid disease of the pelvis presenting as bubbly cystic, expansile lesions with surrounding reactive sclerosis. (A) A solitary large multilocular cyst in the right iliac bone. There is expansion of the iliac crest with cortical breakthrough and a thin reactive layer of bone sclerosis about the lesion. (B) Bubbly cystic, expansile lesion involving the pubis, ischium, and acetabulum on both sides of the pelvis. Hydatid disease may cross the pubic symphysis, as in this case, or the sacroiliac or hip joints. Fig. 3.134 Hydatid disease involving the right ilium and resembling chondrosarcoma. There is a diffuse multicystic type of bone destruction intermingled with irregular, coarse trabecular strands and islands of dense bone. The calcification, cortical destruction, and surrounding soft tissue mass produce an appearance that may be confused with chondrosarcoma. (Courtesy of Dr. Daniel Wilner: Radiological Diagnosis of Tumors in Bone and Allied Disorders, 1979). ... Fig. 3.135 Extreme destruction of pelvic bones by hydatid disease. There is gross osteolysis with expanded blowout lesions of bone involving the right hemipelvis in (A) and virtually the entire pelvis in (B). The radiographic appearance at this end stage shows a massive destructive process so bizarre that no identifiable osseous features remain. The lumbar vertebral column can be seen to the right of the large expansile lesion arising from the right iliac bone in (A). In (B) the upper sacrum with its spinous processes are barely discernible in the upper portion of the film. In both cases, there is little more than a shell of bone with reinforced trabecular strands and irregular calcifications in these grossly expansile, blowout lesions. Despite the vast loss of bone structure in such cases, the complicating osteitis with its dense reactive new bone formation tends to stabilize the process somewhat, although crippling deformities are obviously present. Next Page Previous Page