Brown tumors developing in renal transplant recipients with persistent hyperparathyroidism: two case reports and review of literature.

BACKGROUND: Brown tumors, evidence for severe hyperparathyroidism, are rare in end-stage renal disease, and are distinctly uncommon in patients with a functioning renal transplant. CASE REPORTS: We report two cases of brown tumors developing after renal transplantation, and discuss their presentation and treatment. We review the literature. CONCLUSIONS: We suggest that persistent hyperparathyroidism post-renal transplant requires aggressive intervention to avoid significant consequences.

Giant cell reparative granuloma: a comparative clinicopathologic study of lesions in gnathic and extragnathic sites.

This study attempts to define the clinicopathologic aspects of extragnathic giant cell reparative granuloma (GCRG) by contrasting it with the much better recognized GCRG of jaw bones and highlights the manifestations that are unique to the extragnathic localization. Ninety-one GCRGs of 89 patients, 22 in jaw bones and 69 in the extragnathic bones, were examined. Females were affected twice as frequently as males in both groups. The age distribution of extragnathic GCRGs overlaps that of gnathic counterparts. Small bones of the hands (17 lesions) and feet (16 lesions) were the most common sites for extragnathic lesions. The radiographic findings were nonspecific. Histology of extragnathic lesions was closely similar to that of lesions affecting the jaw. These giant cell lesions should be distinguished from giant cell tumors. Int J Surg Pathol 9(3):189-200, 2001

Recurrent chondromyxoid fibroma of the thoracic spine 30 years after primary excision: case report and review of the literature.

We report a case of late recurrence of chondromyxoid fibroma (CMF) arising in a thoracic vertebra in an 11-year-old male. This was treated by curettage, and 30 years later, the patient noticed shoulder pain and leg weakness. A recurrent mass appeared at the same site in the spinous process of T6. The histologic features of the recurrent tumor were similar to those of the primary lesion. A total of 38 cases of CMF of the vertebra have been reported. Only 3 of 38 previously reported vertebral CMF recurred. Tumors recurred 2 years after operation in 2 cases, and 7 years after operation in 1 case.

Sarcomatous transformation of the orbit in a patient with Paget's disease.

OBJECTIVE: To report the clinical and pathologic features of sarcomatous transformation of the skull with involvement of the orbit, in Paget's disease. DESIGN: Interventional case report. PARTICIPANT: An 83-year-old woman with Paget's disease who experienced progressive proptosis of the left eye. INTERVENTION: Fine-needle aspiration biopsy of the orbital mass. RESULTS: Cytologic examination revealed round to oval malignant cells with wispy cytoplasm, consistent with the diagnosis of sarcoma. The patient died shortly after institution of orbital radiation therapy and systemic steroid therapy. CONCLUSIONS: Proptosis related to Paget's disease is uncommon, and only rarely is it a result of sarcomatous transformation. Sarcomatous transformation of the skull involving the orbit should be included in the differential diagnosis of progressive proptosis in patients with Paget's disease.

Synovial desmoplastic fibroblastoma of hip joint with bone erosion.

A 78-year-old woman presented with pain at the left hip. Initial radiographs showed minimal age-related changes. Over the next 2 years she developed large erosions in the left femoral neck and proceeded to hip replacement. Histological examination showed bland spindle cells in a loose and hyalinised collagenous stroma considered to represent a desmoplastic fibroblastoma (collagenous fibroma). This is the first reported case of synovial desmoplastic fibroblastoma.

Cherubism: clinicopathologic features.

A case of cherubism in 6-year-old boy is reported. He presented with bilateral symmetrical enlargement of the jaw in addition to medially dislocated premature teeth, narrow V-shaped palatal vault, and mild upward turning of the eyes. Radiographs showed multiloculated osteolysis in both the mandible and maxilla. Histology revealed a non-neoplastic fibrous lesion, rich in multinucleated giant cells, consistent with giant-cell reparative granuloma. Since the original description of cherubism, various histologic interpretations have been proposed, particularly that of fibrous dysplasia. However, it should be emphasized that cherubism is a disease histologically indistinguishable from giant-cell reparative granuloma.

Adamantinoma-like Ewing's sarcoma: genomic confirmation, phenotypic drift.

Ewing's sarcoma, a highly malignant neoplasm, is characterized by an 11;22 translocation [t(11;22) (q24;q12)], resulting in the fusion of genes FLII and EWS. Adamantinoma of extragnathic bones, a low-grade malignant neoplasm with epithelial features, is not typically considered in the differential diagnosis of Ewing's sarcoma. In this study, three osseous Ewing's sarcomas with histological, immunohistochemical, or ultrastructural epithelial features were subjected to reverse transcription-polymerase chain reaction and sequencing studies for the Ewing's sarcoma molecular rearrangement. (Two of the three cases were originally described as adamantinomas or nontypical Ewing's sarcoma before the availability of genetic characterization.) In addition, traditional cytogenetic analysis and a unique combined interphase molecular cytogenetic/ immunocytochemical approach with bicolor 11;22 translocation breakpoint flanking probes (cosmids) and pancytokeratin antibodies were performed on one neoplasm. At(11;22) (q24;q12) was found in one neoplasm and a type II EWS/FLI-1 fusion transcript was detected in all three neoplasms. The combined genetic/immunocytochemical approach revealed the presence of the 11 ;22 translocation in the nuclei of cytokeratin immunoreactive cells. These genotypic and phenotypic findings delineate a novel Ewing's sarcoma histologic variant, "adamantinoma-like Ewing's sarcoma."

Chondrosarcoma of the short tubular bones of the hands and feet.

OBJECTIVE: To report 12 cases of chondrosarcoma in a rare location, the short tubular bones of the hands and feet, as well as 12 cases of enchondroma in similar locations, emphasizing the radiologic and histopathologic features. DESIGN AND PATIENTS: All relevant cases that had both histologic slides and radiographs available were taken from the files of one orthopedic referral hospital and the personal files of one of the authors. A similar number of enchondroma cases was selected at random from the files. RESULTS AND CONCLUSIONS: One malignancy arose in a background of enchondromatosis, with all the others being solitary lesions. A pathologic diagnosis of malignancy is often difficult in the absence of radiologic signs of malignancy (cortical destruction with or without soft tissue extension). However, three cases were unusual in that the initial radiograph demonstrated a benign appearance. Another group of three malignancies was surprisingly indolent biologically. The treatment of choice is ray resection (or more limited amputation in a lesion of the middle or distal phalanx).

Radiographic and histologic patterns of calcification in chondromyxoid fibroma.

OBJECTIVE: To evaluate the frequency of radiologic and histologic manifestations of matrix calcification in chondromyxoid fibromas. PATIENTS: Forty-four cases of chondromyxoid fibroma were reviewed. The age range of the patients was 3-70 years (average 29 years). RESULTS: Calcification was found microscopically in 15 cases (34.1%). In five cases (12.5%) it was demonstrated on plain films or CT. The age range of the patients with microscopic evidence of calcified matrix was 14-70 years (mean 46 years), while that of the patients with non-calcified lesions was 3-59 years (average 21 years). All but two of the patients who showed microscopic calcification in the tumors were over 40 years of age. Four microscopic patterns of calcification were observed: coarse granular, circumscribed, trabecular, and "chicken-wire." CONCLUSIONS: Calcification in chondromyxoid fibroma was found more frequently than in previously reported studies. There was a tendency for this phenomenon to occur in the tumors of older patients, particularly those over 40 years old, and in chondromyxoid fibromas situated in flat bones, including ribs.

Classic adamantinoma in a 3-year-old.

Classic adamantinoma of the long bones is a rare, low-grade malignant neoplasm arising most often in the tibia and usually in patients during the second to fifth decades. Although adamantinomas have been described in children, the histologic pattern in this age group is different from that seen in adults and resembles osteofibrous dysplasia. The usual pattern of adamantinoma in children has been termed "differentiated adamantinoma" and follows a benign course. We report a case of adamantinoma in the proximal tibia of a 3-year-old patient. The lesion had abundant epithelial component with formation of keratin pearls, a pattern that has been described only in classic adamantinoma occurring in adults. Since differentiated adamantinomas are essentially benign and classic adamantinomas are low-grade malignancies, the finding of a classic variant at this young age raised important therapeutic and prognostic issues.

Tophaceous pseudogout (tumoral calcium pyrophosphate dihydrate crystal deposition disease).

Most cases of calcium deposition seen radiologically in soft tissues are caused by calcium hydroxyapatite and occur either as a complication of trauma with associated necrosis (eg, fat necrosis), generalized connective tissue diseases (eg, scleroderma), metabolic disturbances (eg, hyperparathyroidism, familial hyperphosphatemia), sarcoidosis, myeloma, or metastases. Hydroxyapatite deposits are seen at many soft tissue sites, including joint capsules, ligaments, blood vessels, dermis, etc. On the other hand, deposits of calcium pyrophosphate are seen typically in the meniscus, articular cartilage, ligamentum flavum, and intervertebral disc. They usually are punctate or linear in distribution within the meniscus or parallel to the subchondral bone end plate. We report seven cases of massive focal calcium pyrophosphate dihydrate (CPPD) crystal deposition disease (tophaceous pseudogout) that occurred in atypical locations for CPPD. The ages of the patients ranged from 31 to 86 years (average, 60.7 years). One patient was male and six were female. The temporomandibular joint was involved in three patients and the metatarsophalangeal joint of the great toe was involved in two patients. The hip joint and cervical spine were involved in one patient each. A mass or swelling with or without pain was a common symptom. None of the patients in our series had clinical or radiographic evidence of CPPD crystal deposition disease in any other joints. Roentgenograms showed calcified lesions with a granular or fluffy pattern. Histologically, the lesions showed small or large deposits of intensely basophilic calcified material containing needle shaped and rhomboid crystals with weakly positive birefringence characteristic of CPPD. Foreign body granulomatous reaction to the CPPD deposition was constantly found. Chondroid metaplasia around and in the areas of CPPD deposition was observed commonly. Some of the chondroid areas showed cellular atypia in chondrocytes suggestive of a malignant cartilage tumor. It is important to recognize this rare form of CPPD crystal deposition disease and to identify the CPPD crystals in the calcified deposits, thus avoiding the misdiagnosis of benign or malignant cartilaginous lesions.

p53 expression and DNA ploidy of cartilage lesions.

The aim of this study was to investigate the expression of a tumor suppressor gene (p53) in cartilage lesions of bone and its relationship to their histological grade and DNA ploidy. An immunohistochemical assay for p53 and Feulgen-stained DNA preparations was subjected to computerized image analysis. Enchondromas, synovial chondromatosis, and low grade (grade I and II) chondrosarcomas were diploid. High grade (grade III) chondrosarcomas and high grade sarcomatous components of dedifferentiated chondrosarcomas were aneuploid. Well differentiated cartilaginous components of dedifferentiated chondrosarcomas were diploid. Microscopic examination showed weak focal positivity for p53 in one of 10 enchondromas one of six examples of synovial chondromatosis, and three of four low grade (grade I and II) chondrosarcomas. All three high grade (grade III) chondrosarcomas were strongly positive for p53. The high grade sarcomatous component of all four dedifferentiated chondrosarcomas was strongly positive for p53, whereas only focal weak positivity was noted in the well differentiated cartilaginous areas. These results were confirmed by quantitative computer-assisted image analysis, which showed that high grade aneuploid cartilage tumors demonstrated strikingly higher levels of p53 than did diploid low grade malignant tumors or benign cartilage lesions.

Plasma cell myeloma in unusually young patients: a report of two cases and review of the literature.

Two cases of plasma cell myeloma in unusually young patients are reported. One was a case of multiple myeloma involving the skull and ribs in a 23-year-old woman, the other of solitary myeloma of the tibia in a 21-year-old man. Both the cases were non-secretory myeloma; however, monoclonal immunoglobulins were demonstrated by immunohistochemical studies. Plasma cell myeloma in patients below the age of 30 years is extremely rare. Our literature search disclosed 20 well-documented cases of multiple myeloma and 25 cases of solitary myeloma in patients at or below the age of 30. Plasma cell myeloma may occur in young persons, so it should be considered in the pre-biopsy differential diagnosis when bone lesions radiologically consistent with myeloma are encountered in young patients.

Bone cancers.

BACKGROUND: Frequency distribution data for primary bone sarcomas have long been used to provide clues to the diagnosis of bone cancers after their identification in radiographs. Age and skeletal site are often helpful, in addition to specific radiographic features, in narrowing down the probable histologic categories of bone neoplasms before biopsy. METHODS: Data on 2627 histologically confirmed primary malignant tumors of bone, as collected by the SEER program during the period 1973-1987, were analyzed by age, sex, race, and anatomical site. RESULTS: Osteosarcoma was the most frequently diagnosed primary sarcoma of bone (35.1%), followed by chondrosarcoma (25.8%), Ewing's sarcoma (16.0%), chordoma (8.4%), and malignant fibrous histiocytoma, including fibrosarcoma (5.6%). The most frequently diagnosed sarcoma of bone in persons younger than age 20 was osteosarcoma, followed by Ewing's sarcoma. Chondrosarcoma was the most frequently diagnosed bone tumor in the population older than age 50. The overall 5-year relative survival rates were as follows: osteosarcoma, 41.0%; chondrosarcoma, 72.7%; Ewing's sarcoma, 41.2%; chordoma, 63.8%; and malignant fibrous histiocytoma, 42.9%. There was an improvement in the survival rates during the period 1973-1987 for patients with chordoma and for white female patients with Ewing's sarcoma. Ewing's sarcoma and chordoma occurred almost exclusively in the white population. CONCLUSIONS: SEER data provide a unique opportunity to evaluate the incidence and survival rates of bone sarcomas, which are uncommon but highly lethal tumors. The findings from this analysis provide information useful in the diagnosis of these cancers.

Exophytic variant of fibrous dysplasia (fibrous dysplasia protuberans).

Two cases of an exophytic variant of fibrous dysplasia (fibrous dysplasia protuberans) are reported in which the lesions protruded far beyond the normal bone contour mimicking surface lesions of bone. The first case was an 18-year-old man who had a pedunculated calcified mass of the sixth rib in association with radiologically diagnosed fibrous dysplasia of the skull. The second case was a 33-year-old man who had an exophytic lesion of the proximal tibia. Both of these patients were shown to have benign fibro-osseous lesions consistent with fibrous dysplasia. The intramedullary portions of the host bone adjacent to the exophytic masses also were involved by the fibro-osseous lesions and this fact suggests that the lesions may arise eccentrically in the medullary spaces and mainly grow outwards. It is important to be aware that fibrous dysplasia occasionally presents as an excrescence on the surface of bone. Careful radiographic and histological correlation is required to make a correct diagnosis of this rare variant of fibrous dysplasia.