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Biomedical subjects

K K Unni

Publications and source records attributed to K K Unni.

At least 19 recordsLinked to original sources
PubMed1992

Giant cell tumor of the skull.

BACKGROUND: Most giant cell tumors (GCT) occur at the ends of long bones. There is little information about GCT of the skull bones. METHODS: The authors reviewed the Mayo Clinic files, which contained 546 cases of GCT, and their own consultation files, which contained approximately 1500 cases. RESULTS: Eleven tumors occurred in the sphenoid bone with extension to the surrounding bones and structures in 8 patients. One tumor (in Paget's disease) occurred in the frontal bone, one tumor was in the occipital bone, and one tumor was in the temporal bone. There were 4 men and 11 women whose ages ranged from 8 to 78 years, with a mean of 36.5 years. Radiographic findings were not suggestive of a specific diagnosis, although the features were those of an aggressive lesion. Histologically, the tumors had features typical of GCT. However, a prominent spindle cell component was seen in five tumors. The initial treatment in all patients but one was intralesional excision that was as complete as possible. The last patient had a wide excision and had soft tissue recurrence at 1 year. This was excised and she was free of disease at 2.7 years. Three patients died, one in the immediate postoperative period and the other two at 1.6 and 4 years with progression of tumor. One patient had postoperative radiation therapy and was without evidence of disease for 2 years when he was lost to follow-up. The remaining 10 patients all had postoperative radiation therapy; 6 patients were alive without disease from 4 to 34 years. However, one of these six patients had a recurrence that was treated surgically with additional radiation. Four patients were alive with tumor from 2.1 to 26 years at the time of this report. CONCLUSIONS: GCT of the skull bones is rare but should be distinguished from giant cell reparative granuloma because of the tendency for progression. Surgical ablation (as complete as possible) and postoperative radiation therapy seem to be the treatment of choice for GCT of the skull bones.

Adolescent↗
PubMed1992

Aneurysmal bone cyst. A clinicopathologic study of 238 cases.

Aneurysmal bone cyst (ABC) is a nonneoplastic expansile bone lesion that mainly affects children and young adults. Primary ABC is relatively rare, with an incidence one half that of giant cell tumor of bone. In 238 patients with ABC studied in the Mayo Clinic files, more than 80% of the lesions were in long bones, flat bones, or the spinal column. Of the lesions initially treated at the Mayo Clinic, 95% were typical ABC; the rest were "solid" variants. Except for the absence of obvious cavernous channels and spaces, there was no significant histologic difference between solid variant and typical ABC. Radiographically, ABC is an eccentric expansile lesion commonly located at the metaphysis of long bones. Computed tomography and magnetic resonance imaging may show multiple internal septations or fluid levels. In the 153 patients treated, 19% had recurrence after curettage (intralesional excision). Recurrence was most common during the first 2 postoperative years.

Adolescent↗
PubMed1992

Case report 714. Postirradiation osteosarcoma after radiation of metastatic skeletal lesion.

Two cases of postirradiation osteosarcoma are presented--one in a 76-year-old woman with breast carcinoma and subsequent osteosarcoma after radiation therapy for a metastatic lesion in the right tibia, and the other in a 16-year-old girl with hepatocellular carcinoma metastatic to the left tibia and osteosarcoma after radiation therapy to that bone. Microscopically, both cases were high-grade spindle cell lesions with osteoid production. Both patients fared poorly. This is a rare complication of radiation therapy.

Adenocarcinoma↗
PubMed1992

Sarcomatous transformation in cranial chordoma.

In a study of 52 patients with cranial chordoma treated at the Mayo Clinic over a 19-year period (1966-1984), two tumors showed anaplastic features, both de novo, i.e., unassociated with prior irradiation. The incidence of anaplastic transformation was thus 4%. Immunohistochemistry showed the mixed mesenchymal-epithelial phenotype typical of chordoma in portions of both tumors, but loss of reactivity for keratin and epithelial membrane antigen was noted in anaplastic components. The study indicates that sarcomatous change in chordoma is a rare event that may occur de novo and is associated with the loss of immunophenotypic features of epithelial differentiation.

Biomarkers, Tumor↗
PubMed1992

Benign giant-cell tumor of bone with pulmonary metastases: clinical findings and radiologic appearance of metastases in 13 cases.

Tumors that metastasize are considered "malignant" by definition. However, benign giant-cell tumor of bone is an exception because of the potential for histologically benign pulmonary metastases, a fact seldom emphasized in the radiologic literature. We therefore report our experience with 13 cases of pulmonary metastasis among 475 patients (prevalence, 3%) in whom benign giant-cell tumor of bone was diagnosed before 1990 at our institution. Five (38%) of the 13 primary bone tumors were located in the distal radius. Local recurrence at the site of the primary bone tumor tumor occurred in seven patients (54%) before pulmonary metastases developed. The mean interval from the diagnosis of the primary bone tumor to the onset of pulmonary metastasis was 3.8 years, with a maximum of 10.7 years. Fifty-four percent of the patients (7/13) had pulmonary metastases 3 years after diagnosis of the primary bone lesion, and 92% (12/13) had pulmonary metastases 7.5 years after diagnosis. Overall mortality rate directly due to giant-cell tumor and its metastases was 23%. On chest radiographs and CT scans, pulmonary metastases appeared as rounded, nodular opacities of homogeneous density, ranging from 0.5 cm to 8.0 cm in diameter. Peripheral regions of the lungs were involved in 85% of the cases and basilar regions in 62%. Our study shows that benign giant-cell tumor of bone can produce pulmonary metastases, that metastases most often occurred with recurrent local disease and distal radial lesions, that the prognosis was relatively favorable, and that such metastases had no distinguishing radiologic features.

Adult↗
PubMed1991

Desmoplastic fibroma of bone.

Desmoplastic fibroma is a rare primary tumor of bone that histologically and biologically mimics the extra-abdominal desmoid tumor of soft tissue. This study reviews 27 cases of desmoplastic fibroma, consisting of 9 from the Mayo Clinic files and 18 from our consultation files. There was a male predominance, and 74% of the patients were in the first 3 decades of life. The most frequent sites of involvement were the metaphysis of long bones and the mandible. Radiographically, the tumors were lucent, expansile lesions with well-defined margins. Histologically, they contained slender spindle cells and various amounts of collagen fibers. En bloc resection is the treatment of choice because a high incidence of recurrence was noticed after lesional curettage.

Adolescent↗
PubMed1991

Osteoblastoma response to chemotherapy.

An 8-year-old boy had an osteoblastoma of the body of C2. After attempted excision, the tumor recurred rapidly and massively. The tumor shrank progressively after treatment with high-dose methotrexate, doxorubicin, and cisplatin. The patient has stopped treatment and been stable for 33 months. Surgical excision remains the treatment of choice for osteoblastoma. Chemotherapy may be useful in selected patients with a recurrent, aggressive tumor or in patients with surgically inaccessible disease.

Bone Neoplasms↗
PubMed1991

Chondrosarcomas of the synovium.

Chondrosarcoma of the synovium, either primary or secondary to synovial chondromatosis, is rare. Ten cases of synovial chondrosarcoma were studied (four from the Mayo Clinic files and six from the authors' consultation files). Two were considered primary. In five cases there was evidence of preexisting synovial chondromatosis, and in the remaining three, there was a suggestion of preexisting disease. Several histologic features were found that were helpful to diagnose malignancy. The most important ones were loss of the "clustering" growth pattern typical of synovial chondromatosis, myxoid change in the matrix, areas of necrosis, and spindling at the periphery of chondroid lobules. Pulmonary metastasis developed in five of nine patients; three of these patients died.

Adult↗
PubMed1991

Solitary congenital fibromatosis (infantile myofibromatosis) of bone.

Congenital fibromatosis is a rare and benign myofibroblastic tumor that may occur in either a solitary or multicentric form. The soft-tissue form of this entity is well recognized. This report analyzes the clinical and pathologic features of 14 cases of congenital fibromatosis in which the tumor existed as a solitary lesion in bone. Most of the tumors (71%) were in patients who were 2 years old or younger. All but one tumor involved the craniofacial bones. Radiographically, they were purely lucent lesions in which a sclerotic rim was visible in each skull lesion. The myofibroblastic appearance closely resembled the microscopic features seen in the soft-tissue counterpart. For appropriate surgical management, it is imperative to recognize that this tumor occurs as a solitary lesion in bone and that it is distinct from other, more aggressive fibrous lesions.

Adolescent↗
PubMed1991

MR imaging of synovial sarcoma.

The MR imaging findings in 12 cases of synovial sarcoma are illustrated. The MR appearance most indicative of the tumor is an inhomogeneous septated mass with infiltrative margins located close to a joint, a tendon, or bursae, especially if soft-tissue calcification can be seen on CT scans or plain radiographs.

Adolescent↗
PubMed1991

Anomalies of the fingers and toes associated with Klippel-Trenaunay syndrome.

Klippel-Trenaunay syndrome is a rare congenital malformation characterized by a large angiomatous nevus; hypertrophy of soft tissue or overgrowth of bone, or both; and venous varicosities. The cases of 108 patients who had a diagnosis of this syndrome between 1956 and 1990 were reviewed. One hundred and twenty-six anomalies were found in twenty-nine patients, each of whom had one to thirteen malformations of the fingers or toes, or both. The ratio of female patients to male patients was approximately two to one. Twenty-six patients had macrodactyly affecting one to six digits; nine, syndactyly involving two or more digits; five, metatarsus primus varus; two, clinodacytly; two, polydactyly; one, camptodactyly; and one, a congenital trigger finger. Thirty-three of the 126 anomalies were in extremities that had no nevi, varicose veins, or generalized hypertrophy.

Adolescent↗
PubMed1991

Telangiectatic osteosarcoma.

Telangiectatic osteosarcoma is a rare variant of osteosarcoma. In the original report from the authors' institution, a poor prognosis was noted. The authors have updated their experience with this entity. The prognosis for patients with telangiectatic osteosarcoma has improved remarkably. The prognosis in the present series seems to be the same as that for conventional osteosarcoma. Adjuvant chemotherapy seems to help in salvaging patients with metastatic disease. However, in this small series, survival of patients without metastasis is apparently not influenced by whether they received chemotherapy.

Adolescent↗
PubMed1991

Primary orbital intraosseous hemangioma.

Primary orbital intraosseous hemangiomas are rare--only 16 cases have been reported previously. The authors describe five patients with this benign tumor. Patients ranged in age from 49 to 77 years, and each had a painless or mildly tender nodular lesion. Ophthalmic symptoms were minimal, although nasolacrimal obstruction was the original sign in one patient. Four of five patients responded well to complete tumor excision (two patients) or partial resection of the lesion (two patients). The fifth patient required a second operation for tumor progression after partial excision of the hemangioma. The 16 previously reported cases of orbital intraosseous hemangioma are reviewed, and the natural history and pathology of this rare vascular lesion are discussed.

Aged↗
PubMed1991

Diagnosis of diffuse malignant mesothelioma: experience of a US/Canadian Mesothelioma Panel.

The experience of the US/Canadian Mesothelioma Panel with its first 200 cases is reviewed. The light microscopic diagnosis, histochemical findings, immunohistochemical findings, and electron microscopic features of malignant mesotheliomas are reviewed in the context of differential diagnosis. Reasons for referral of case material to the panel and lessons from follow-up of difficult and controversial cases are reported. Recommendations to general pathologists are made regarding evaluation and review of possible mesotheliomas.

Adenocarcinoma↗
PubMed1990

Chondrosarcoma of bone in children.

Chondrosarcoma of bone rarely occurs in children. This report analyzes the clinicopathologic features in a series of 47 patients with conventional chondrosarcoma who were less than 17 years of age. Of the 47 cases, 14 were from the Mayo Clinic files, and 33 were from our consultation files. Most of the lesions occurred in the trunk and upper ends of the long bones, with the humerus being the most frequent skeletal site. Twelve of the 47 tumors were secondary. The radiographic findings were the same as those seen in adult chondrosarcoma. Pathologically, the tumors were low grade. En bloc resection is the treatment of choice because of the high incidence of local recurrence with lesser surgical margins. Prognosis in childhood chondrosarcoma is no different from that in adult chondrosarcoma. None of the patients with follow-up data had metastasis.

Adolescent↗