Search

Chronic recurrent multifocal osteomyelitis (CRMO), an autoinflammatory bone disorder characterized by non-bacterial osteomyelitis causing recurrent multifocal bone lesions, is a well-known, yet uncommon pediatric condition that rarely affects adults; to date, it has never been diagnosed over the age of 75. The following report will discuss the first octogenarian diagnosed with CRMO and therefore represents an exceptionally rare presentation of a rare disease. An 83-year-old woman presented with progressive right shoulder, forearm, and hip pain, with associated weight loss and global weakness, requiring a wheelchair for mobility. Imaging revealed a pathologic right ulna fracture in addition to lytic lesions of the right proximal humerus and proximal femur. The clinical picture was thus that of a patient with probable multiple myeloma versus metastatic disease. After an extensive workup, however, the lesions were not malignant; histologic findings were instead suggestive of chronic osteomyelitis with negative cultures. Given the multifocal nature of this condition, combined with a lack of clinical symptoms of infection, a diagnosis of CRMO was rendered. The patient underwent intramedullary nailing of the right femur and splinting of the ulna, with a subsequent remarkable recovery to painless ambulation, complete union of the right ulna fracture, and resolution of the lytic lesions without receiving any targeted medical treatment. This case highlights the importance of maintaining CRMO on the differential for multifocal skeletal lesions, regardless of age. Performing a thorough workup with necessary imaging, biopsy, and culture are critical to establishing this diagnosis, which can only made as a diagnosis of exclusion., (© 2024. The Author(s).)

A 32-year-old male presented with a right thumb lesion of 11-month duration. A clinical diagnosis of pyogenic granuloma was entertained but the lesion failed to respond to conservative therapy and eventually necessitated amputation of his thumb. MRI of the right thumb showed an ill-defined, heterogeneously enhancing, infiltrating mass within the dorsal soft tissues abutting the distal phalanx and measuring 4.2 × 2.4 × 0.7 cm. Histologically, the tumor was composed of a high-grade osteosarcoma with a chondrosarcomatous component localized within the underlying bone and a more superficial spindle cell component in the overlying soft tissue. The epidermis was focally ulcerated overlying the lesion. The key to the diagnosis was provided by intense staining of the spindle cell component for S100 protein indicative of a spindle cell melanoma. The presence of an associated osteogenic sarcomatous component established a final diagnosis of osteogenic melanoma. The localization of this element to phalangeal bone is distinctly unusual and resulted in the close resemblance to a primary osteogenic sarcoma.

We report a case of a 23-year-old female with pain and fullness in the right popliteal fossa. An MRI scan demonstrated an ossified enhancing soft tissue mass. Evaluation of the resected specimen showed a high-grade extraskeletal osteosarcoma juxtaposed to the three zones of myositis ossificans. At 1-year follow-up the patient is alive and disease free. A review of the literature purporting to document such an association failed to demonstrate a single case in which an osteosarcoma and MO with its zonal architecture co-existed.

Extraskeletal osteosarcoma (ESOS) originating in the subcutaneous tissue is a rare occurrence, accounting for less than 10 % of ESOS cases. Osteosarcoma of extraskeletal origin accounts for approximately 2-4 % of all osteosarcomas, and 1 % of soft tissue sarcomas. We report a case of an 80-year-old female with an isolated primary subcutaneous tumor of the forearm. After imaging, surgical excision, and pathological analysis, the diagnosis of a subcutaneous osteosarcoma was made. This report documents the clinical and pathological findings of subcutaneous ESOS in this case, along with a review of previous cases of subcutaneous ESOS.

Hypersensitivity to orthopedic implant materials has been well documented with potential catastrophic consequences if not addressed pre-operatively. The spectrum of reactions is wide, from mild non-specific pain with localized erythema to severe periprosthetic inflammatory destruction and pseudotumor formation. It is therefore essential to identify patients who have or are at risk for implant-associated hypersensitivity. Although metal sensitivity is commonly cited as the cause of these reactions, methyl methacrylate (MMA) has rarely been implicated. To the best of our knowledge, methyl methacrylate-associated pseudotumor formation has not yet been described. The following is a case report of a 68-year-old female who, after undergoing a routine cemented right total knee arthroplasty, developed a painless, enlarging mass during a 13-year period. This mass was found to be a pseudotumor in association with methyl methacrylate hypersensitivity. A review of pseudotumor pathogenesis, methyl methacrylate hypersensitivity, and preoperative preventative care is discussed.

Primary perivascular epithelioid cell neoplasms (PEComas) of bone are rare mesenchymal tumors. Histologically, they are composed predominantly of perivascular epithelioid cells and have the capacity to metastasize. PEComas have been reported within intra-abdominal and intra-pelvic organs. To the best of our knowledge, only seven primary PEComas of bone have been described in the English literature. We present two cases of PEComa of bone, one arising from the distal fibula and one from the acetabulum. Both were treated by surgical excision and one also received adjuvant chemotherapy.

Bizarre parosteal osteochondromatous proliferation (BPOP), or Nora's lesion, is an unusual surface-based lesion of bone found most commonly in the hands and feet. In the original description of the lesion and in all publications that followed, one of the key imaging characteristics used to define this entity was the lack of cortico-medullary continuity with the underlying bone. The authors present 4 unique cases of pathologically proven BPOP in which cortico-medullary continuity with the underlying bone was demonstrated on imaging. It is believed that florid reactive periostitis, BPOP and turret osteochondroma may reflect points along the same continuum with trauma the likely inciting event. The authors suggest that, given this continuum, it may be possible to have BPOP lesions demonstrating overlapping imaging features with osteochondroma. If this is the case, strict adherence to the standard imaging criterion of lack of continuity between the lesion and the underlying bone may lead to misdiagnosis of these unusual cases of BPOP as osteochondromas.

Low grade central osteosarcoma is a distinct, rare low grade malignant neoplasm characterized histologically by a spindle cell proliferation associated with trabecular bone formation. This tumor usually carries a good prognosis. However, it has the potential to recur, dedifferentiate, and metastasize subsequent to surgical treatment. In extremely rare occasions, LGCOS presents with areas of dedifferentiation upon initial patient evaluation. In this report we describe one such case affecting the fibula of a 39-year-old female, presenting with pain. Initial biopsy demonstrated a high-grade osteosarcoma. No areas of LGCOS were seen histologically. Following biopsy the patient received 3 months of chemotherapy at a different institution. However, the patient continued to exhibit symptoms. X-rays indicated a very aggressive tumor in the diaphysis of the proximal fibula, MRI revealed soft tissue involvement. The tumor and surrounding soft-tissues were excised en bloc at our institution. Microscopically, the lesion consisted of high-grade osteosarcoma as well as an underlying LGCOS that involved the cortex and medullary cavity of the fibula. The two histological components of the tumor were sharply delineated from one another. No chemotherapy effect was appreciated histologically or clinically. Eight months following the surgery, the patient died from lung metastases. This is the third documented case of dedifferentiated LGCOS at initial presentation. This case reveals that the low-grade component was also evident on preoperative radiographs.

Epidermal cyst within a toe phalanx is an extremely rare condition. It is important to differentiate this benign lesion, which can be easily treated by curettage, from other benign and malignant lesions of the bone with a similar clinical presentation, and which may require amputation of the toe. This report describes one such lesion in the mid-phalanx of the fourth toe in a 48-year-old woman, and which was successfully identified by intra-operative frozen diagnosis and treated by curettage.

A 9-year-old girl with multiple osteochondromatosis presented with a 1 year history of a gradually enlarging surface lesion originating from the midsection of the right humerus, distal to an osteochondroma. Radiographically and histologically this lesion proved to be a periosteal chondrosarcoma adjacent to an osteochondroma.

We describe two cases of pigmented villonodular synovitis affecting true bursae. This study was also designed to discuss the term "pigmented villonodular bursitis", not confined to true synovial bursae, sometimes creating misunderstanding.

We report a case of a 14-year-old boy with an intracompartmental lytic lesion with poorly defined margins in the right distal tibia that was originally treated with curettage and bone grafting. Histologic examination showed an osteoblastic tumor with unusual features, which was found on consultation to be an osteoblastoma-like osteosarcoma, a rare, low-grade variant of osteosarcoma. Subsequently, the patient underwent en bloc resection of the distal tibia, which was replaced with vascularized bone graft and followed by chemotherapy. Two years later, he is alive with lung metastases.

Hereditary bone dysplasia (HBD) is an extremely rare clinicopathological entity manifested by diaphyseal medullary stenosis and cortical bone thickening associated with a propensity for fractures affecting the long tubular bone. Malignant transformation has been reported to occur at an alarming frequency. The hereditary pattern appears to be autosomal dominant. In this paper we present the case of a 19-year-old man with hereditary bone dysplasia who was unaware of his underlying condition until he presented with malignant transformation arising in an area of bone infarct of the left tibia.

Multifocal osteosarcoma is uncommon. Long-term survival of an incompletely treated case is exceptional. We report an unusual case of bifocal sclerosing osteosarcoma in a 38-year-old women that involved the left ilium and right proximal femur. The femoral lesion was resected. The tumor in the left ilium was not treated. She did not receive chemotherapy and has been free of metastases for 7 years. Recently, growth of the pelvic osteosarcoma has resulted in vascular compression and edema of the lower extremity. The patient's alkaline phosphatase has been elevated throughout. The tumor was HMB-45 positive, which has not been previously reported in osteosarcoma. The pathogenesis of multifocal osteosarcoma is discussed.

A cold abscess secondary to tuberculous spondylitis or osteomyelitis is a well-recognized entity. However, a soft tissue tuberculous abscess without bone involvement is rare. We present such a case.

Objective: To evaluate the signal characteristics of primary non-Hodgkin's lymphoma of bone on MRI. DESIGNS AND PATIENTS: Ten patients with primary non-Hodgkin's lymphoma of bone were included in the study. T1- and T2-weighted imaging was performed. The signal intensity of the lesions was compared with that of the surrounding muscle., Results: The results of the MRI were compared with the histological findings. In the majority of cases (5/10) the lesion involved the femur. In one case each the tibia, humerus, ileum, sacrum, and skull, respectively, were affected. A soft tissue mass was present in four cases. In nine of ten cases on T1-weighted imaging the lesion was hypointense. On T2-weighted imaging seven of ten lesions were hypointense compared with muscle, one isointense and, in two cases, part of the lesion showed slightly hyperintense signal. In all ten cases the signal pattern appeared inhomogeneous. Pathological examination showed extensive fibrosis in the majority of cases., Conclusion: According to our results there is decreased signal intensity of bone marrow on both T1- and T2-weighted imaging, unlike other primary round cell tumors of bone. Because the diagnoses were established with small tissue biopsies, the reason for these findings is speculative.

The case of a 55-year-old man with chondrosarcoma to the cervical spine is described. Two years previously the patient had undergone a right hip replacement for synovial chondromatosis. Re-evaluation of the biopsy specimen from the right hip taken at the time of the initial operation showed areas of chondrosarcoma arising in the background of synovial chondromatosis. The unusual presentation of this rare entity is discussed.

A 35-year-old woman presented with a painful swelling in the left distal radius that had been present for 1 year. Radiography and computerized tomography revealed a sclerotic surface lesion that had grown over the year and eroded the cortex. Histological examination demonstrated two distinct components: a cartilaginous low- to moderate-grade osteosarcoma on the surface and a high-grade osteosarcoma in the intramedullary component. This case is uncommon in two aspects: the radius is a rare site for such a tumor and the dedifferentiation was revealed at the time of the first surgery and was not secondary to recurrence.

We present the case of a 53-year-old patient with fibrocartilagenous dysplasia. The area involved was in the proximal femur and presented a lytic lesion with extensive calcifications which radiologically mimicked chondrosarcoma. The radiopathological pattern of this rare entity is discussed in detail and the literature reviewed.

Objective: To evaluate the role of magnetic resonance imaging (MRI) and computed tomography (CT) in the diagnosis of intramuscular ganglia (IMG) that arise from the superior tibiofibular joint (STFJ)., Material and Methods: Our series consisted of three men and three women. Four patients were studied by MRI, one by CT only, and two by both modalities. Contrast was used in one of the two patients studied by CT. MRI was obtained in at least two orthogonal planes to demonstrate the relation of the ganglia to STFJ., Results: The MR and CT appearance of these ganglia was basically that of a well-defined soft tissue mass with low attenuation on CT images consistent with the presence of fluid. On MR studies, they had an isointense signal on T1-weighted images and a homogenous high-intensity signal on T2-weighted images. MRI demonstrated the attachment of these ganglia to the STFJ., Conclusion: CT and MRI were effective, noninvasive modalities in the evaluation of IMG. The imaging features on both modalities were consistent with the presence of fluid- containing lesions that had close proximity and were attached to the STFJ. The combination of location and the fluid consistency of these lesions facilitated the diagnosis.

An extremely rare case of multicentric periosteal osteoid osteoma in a child was presented. The lesions were found to be embedded in a narrow elliptical strip, suggesting the possibility that lesional tissue was stretched in a longitudinal fashion as a result of the rapid skeletal growth. In young patients with stretched periosteal reaction who complain of pain, multicentric osteoid osteoma should be suspected. These nidi can be obscured by the exuberant periosteal reaction. Accurate evaluation of the radiographic findings is very important.

A case of an elastofibroma in the right scapular region in a 56-year-old woman was reported. The clinical and pathological findings were discussed. The location of this lesion was uncommon. The common sites were mentioned. The differential diagnosis and magnetic resonance findings were also described.

We reviewed the magnetic resonance (MR) appearances of 13 malignant fibrous histiocytomas (MFH) of soft tissue and correlated each with the respective lesion's histopathology. The MR images were evaluated for signal intensity on T1- and T2-weighted spin echo sequences, homogeneity of the lesion, presence of internal low signal septations, and margin definition. Histologic subtypes of MFH included storiform-pleomorphic, giant cell, myxoid, and inflammatory. We could not establish a correlation between MR appearance and histopathology. Instead, our series exhibited general features suggestive of malignant soft tissue neoplasms, namely poor margin definition, internal low signal septation, and heterogeneous high signal intensity on T2-weighted images.

A case of parosteal osteosarcoma arising in the radius was presented. The site is uncommon, being represented in about 1% of all reported cases of parosteal osteosarcoma. The clinical and radiographic characteristics of this lesion were described and the histological as well as the differential diagnosis discussed.

A case of juxtacortical chondromyxoid fibroma in a 31-year-old man was reported. Proof of the diagnosis was obtained by an open biopsy. The histopathology of chondromyxoid fibroma was discussed at length. The radiographic appearances and the differential diagnosis were also described.

An exceptionally rare case of periosteal Ewing's sarcoma involving the mid shaft of the right tibia was reported. In this case, MRI was the technique that confirmed the integrity of the bone marrow. The clinical, radiographic, and histopathologic features of Ewing's sarcoma have been discussed, as has the differential diagnosis of the periosteal type of this tumor.

A case of prolonged history of synovial chondromatosis of the knee joint that transformed into low-grade chondrosarcoma was reported. The pathological differentiation of this rare entity from synovial chondromatosis has been discussed, as have the radiographic appearance and differential diagnosis.

And unusual case of giant cell tumor in a 3-year-old girl has been presented. The topic of giant cell tumors has been discussed at length. The pathology and the differential diagnosis have been considered. The incidence of giant cell tumors in children and adolescents has also been reviewed and proved to be extremely rare.

A case of osteochondroma of the pelvis secondary to radiation therapy after radical nephrectomy for a Wilm's tumor is reported. The occurrence of such a complication has been discussed. Proof was obtained by open biopsy. The indications for surgical resection of such a tumor were considered. The differential diagnosis, though limited, was discussed.

A case of osteochondroma of the pelvis secondary to radiation therapy after radical nephrectomy for a Wilm's tumor is reported. The occurrence of such a complication is discussed. Proof was obtained by open biopsy. The indications for surgical resection of such a tumor were considered. The differential diagnosis, although limited in scope, was discussed.

We described a case of high-grade surface sarcoma of the radius in a 14-year-old boy. The lesion appeared radiologically benign and was confined to the surface. The tumor was resected. At the time of biopsy both lungs showed diffuse metastases. Following surgery the patient underwent chemotherapy and the lung metastases improved. The pertinent literature was briefly discussed.

A large variety of tumor and tumor-like conditions have been shown to originate from the surface of bone (Table 1). Most surface lesions are associated with periosteal reaction. The periosteum is a multipotential membrane. Its cellular composition may give rise to a variety of both neoplasms and tumor-like conditions. To avoid misinterpretation, the orthopedist, radiologist, and pathologist should be familiar with the entire spectrum of surface lesions. A better understanding of the natural history and biological behavior at different lesional maturity stages and correlation of the history with the radiographic and pathological findings is essential to establish the correct diagnosis. A history of injury or blunt trauma is very important. A stress fracture may produce a periosteal reaction acd callus that can be difficult to distinguish from osteosarcoma. In this review article, the authors wish to describe and define each term by its anatomy and radiographic features while discussing the entire spectrum of surface lesions. All the illustrative cases in this review article have been proven histologically.

We have presented a young adult with alveolar soft part sarcoma. The lesion occurred in the ankle region and caused extensive bony erosion that mimicked metastasis. At the time of presentation, gingival and subcutaneous metastases were present. Within a short period, however, the patient developed disseminated lung and skeletal metastases as well.

A rare case of primary leiomyosarcoma of the proximal end of the shaft of the right femur in a 52-year-old man has been reported. Proof was obtained by an open biopsy. The origin, pathological features, and clinical presentation have been discussed. The radiographic appearance, the differential diagnosis, and the poor prognosis of this tumor have also been indicated.

The MRI features of bilateral xanthoma of the achilles tendon in type II hyperlipoproteinemia are reported. MRI has proved to be the best imaging modality available in assessing enlargement of the Achilles tendon. It demonstrates the heterogeneous signal on both T1- and T2-weighted images where the xanthomatous deposits are relatively higher in signal intensity than the tendon itself. MRI also has a potential value in the clinical assessment and therapeutic response of the xanthoma after operative intervention.

We present a patient with parosteal osteosarcoma. The lesion arose at the surface of the femur without involvement of the marrow cavity. Some 24 months following resection of the involved bone, she developed distant metastases with no evidence of local recurrence. Neither the primary nor the metastatic lesions showed high-grade malignancy.

Eight bone tumors with associated transarticular invasion of the sacroiliac joints are described. All invaded the true synovial joint and spread to the opposing bone. One tumor was benign, and the other seven were malignant. Five of the seven were primary and two were metastatic cancer. One, a myeloma, invaded the disc spaces between the fourth and fifth lumbar vertebrae and the fifth lumbar vertebra and sacrum as well as the sacroiliac joint. The right facet joints of the two vertebrae were also invaded. After a thorough search of the literature, we find that the sacroiliac joint is the most common joint to be invaded by tumors. This is followed by the vertebral disc spaces and, last, the facet joints. Apart from these joints, we were unable to find any radiographic documentation of other joints being transarticularly invaded by tumors. We noted that there is a direct relation between transarticular tumor spread and joints that lack mobility and that certain tumors, benign and malignant, tend to invade these joints.

A case of chondroblastoma involving the right acetabulum and superior pubic ramus in a 60-year-old man has been presented. Tissue was obtained by open biopsy. The clinical and radiographic characteristics of chondroblastoma in general, and this tumor in particular, were discussed. The histopathology and differential diagnosis were also considered. The relatively uncommon site of the tumor and its occurrence in an older patient made the radiographic diagnosis difficult, and other possibilities were discussed.

A case of primary liposarcoma of bone involving the glenoid region of the right scapula in a 57-year-old man is presented. The diagnosis was confirmed by open biopsy. The differential diagnoses have been considered. To the best of our knowledge, this may be the first reported case of primary liposarcoma of bone in the scapula.

We report two cases of fibromyxoma, one affecting the iliac crest and the second involving the proximal shaft of the tibia. Fibromyxoma is a rare neoplasm related to benign fibrous tumors and is characterized by exuberant, extracellular, ground substance production. Its histologic appearance is benign and distinctive and can be readily distinguished from that of myxoid chondrosarcoma or chondromyxoid fibroma. The radiographic picture is, however, difficult to interpret, and the entity can be easily mistaken for other tumors.

A case of OCC in a 35-year-old woman is presented. Proof was obtained by open biopsy. This rare entity is benign and its etiology is still obscure. No definite association with osteitis pubis or osteitis condensans ilii has been reported. The involvement of the clavicle is invariably unilateral. The clinical and radiographic characteristics of this benign condition have been discussed and the differential diagnosis has been considered. Consideration should be given to the concept that if the imaging features are characteristic, as in this case, biopsy may not be necessary.

Six patients with spinal cord compression as the presenting symptom of malignant lymphoma are described. These patients suffered from back pain for several months and were diagnosed after sudden paraparesis appeared. Five patients were treated by operative decompression followed by local irradiation, and all regained their motor function. A sixth patient presented with a more insidious paraparesis. A bone marrow aspiration established the diagnosis of malignant lymphoma, and this patient recovered with radiation and steroids alone. Thus, we recommend considering malignant lymphoma as a possible cause of acute cord compression, attempting to establish the diagnosis on an emergency basis within several hours, and attempting to achieve decompression with local radiotherapy and intravenous dexamethasone.