Primary patellar tumors

Bilateral Simultaneous Primary Patellar Giant Cell Tumors

Giant cell tumor is a relatively frequent benign bone tumor; that is usually exhibited in the epiphyseo-metaphyseal region of long bones. Computed tomography and magnetic resonance imaging may show cortical thinning and endosteal scalloping of the bone cortex in giant cell tumors. In radiologic imaging, the giant cell tumor of the bone is a heterogeneous mass because it contains many components, such as solitary mass, cystic areas, and bleeding. The occurrence of giant cell bone tumor in the patella is a rare condition and in this letter, we have reported the unusual coexistence of giant cell tumor on the bilateral patella at the same time. To the best of our knowledge, there is no reported case in the literature of bilateral patellar giant cell tumors.

Oesophageal carcinoma with solitary patellar metastasis: a rare case report

The incidence of tumours found in the patella, including primary and metastatic tumours, is low. Solitary metastasis of oesophageal carcinoma (OC) in the patella is even rarer. A 50-year-old man presented to our clinic because of pain and limited range of motion in the right knee for 4 hours and after a fall. On the basis of the patient’s medical history, he was diagnosed with OC 2 months previously and underwent two cycles of paclitaxel liposome combined with tiggio chemotherapy (oral tiggio, 40 mg, two times/day, with a treatment cycle of 3 weeks). A 99mTc-methylene diphosphonate bone scintigraphy scan showed increased radioactivity in the right patella. A right knee biopsy showed the presence of patellar metastasis from OC. Unfortunately, the patient denied additional treatment and was discharged for personal reasons. At the 1-month follow-up, which was conducted by a telephone survey, we learned that the patient had died of acute pulmonary embolism. X-rays and computed tomography are useful for diagnosing patellar metastases, but 99mTc-methylene diphosphonate bone scintigraphy can help physicians diagnose patellar metastasis of OC more rapidly. Biopsy with pathology is the gold standard for diagnosing patellar metastases. Additionally, timely surgical treatment prolongs the survival time of these patients.

Giant Cell Tumor with Secondary Aneurysmal Bone Cyst of the Patella: A Case Report

A 15-year-old girl presented with pain and swelling on the anterior aspect of the right knee for one year. The radiological evaluation with x-rays and magnetic resonance imaging suggested a benign aggressive lesion of the right patella with a cortical breach. Core needle biopsy of the lesion revealed it to be a giant cell tumor (GCT). She was treated with total patellectomy and end-to-end repair of quadriceps to the patellar tendon. The histopathological report of the whole specimen revealed it to be a GCT with secondary aneurysmal bone cyst (ABC). After 24 months, she was asymptomatic, and there was no evidence of local recurrence or distal metastasis. An extensive review of the literature revealed only four cases of combined GCT with secondary ABC in the patella. Though rare, GCT with secondary ABC of the patella should be kept as a differential diagnosis for anterior knee pain and swelling in young patients. The diagnosis is solely based on histopathological findings. It is imperative to obtain a precise tissue diagnosis in the preoperative period to plan appropriate treatment. 

Patellar metastasis from primary tumor

Although bone tumors are frequently located in the knee area, primary tumors of the patella are rare and patellar metastases are even rarer. Knee pain is the most common complaint of patients with patellar metastases. Owing to the low incidence of patellar metastases, misdiagnosis is not unusual. The present review analyzes ~44 cases of patellar metastases originating from distinct primary sites. Reports of malignant tumors of the lung and kidney metastasizing to the patella were more common than those of other patellar metastases. Relative incidence, symptomatology, imaging features, histopathology and treatment options for these patellar metastatic lesions are described respectively along with a review of the literature. Despite numerous experiments demonstrating the reasons for implantation of tumor in patella, the answer to this question has not yet been revealed. In the light of the increasing attention on the diagnosis and the treatment of these lesions, the availability of the integrated information regarding metastases in the patella becomes more relevant.

TUMORS OF THE PATELLA: THE EXPERIENCE OF INSTITUTE OF ORTHOPEDICS AND TRAUMATOLOGY AT UNIVERSITY OF SÃO PAULO, BRAZIL

Objective:

To obtain epidemiological data from the tumors of the patella diagnosed and treated at the Instituto de Ortopedia e Traumatologia do Hospital das Clínicas da Universidade de São Paulo (IOT-HC-FMUSP) between 1998 and 2015.

Methods:

Series of cases with retrospective evaluation of patients diagnosed with tumors located in the patella. The data was obtained from the records and patients' charts at the Department of Pathology of IOT-HC-FMUSP.

Results:

A total of 2220 medical records from patients with anatomopathological reports were included in the study. Only eight (0.3%) patients had patellar tumors. We found that six (75%) of these were benign, one (12.5%) was a pseudotumoral lesions and one (12.5%) was reported as malignant. Among benign tumors, the giant cell tumor (GCT) was the most frequently reported corresponding to 50% of the cases. Hemagioendothelioma was the only case of malignant tumor in this series. As for the pseudotumoral lesions, we found a brown tumor.

Conclusion:

From the data obtained retrospectively in a 17 year time frame, in a service that treats benign, malignant and pseudotumoral bone lesions, we conclude that our casuistry in patellar tumors is similar to that reported in scientific literature, where benign tumors are predominant in a 7:1 ratio over malignant tumors, being a rare location of appearance, with the GCT as the most common diagnosis . Level of Evidence IV, Case Series.

Unusual Presentation of Anterior Knee Pain in Elite Female Athletes: Report of Two Cases

Two elite female athletes presented with anterior knee pain with range of motion and reproducible tenderness to palpation. Diagnostic arthroscopy was performed in both cases resulting in excision of a nodular pigmented villonodular synovitis (PVNS) in the first patient and scar tissue in the second patient. Correct diagnosis of anterior knee pain in the elite female athlete can present a challenge to clinicians. Although patellofe-moral pain is the most common diagnosis, other uncommon causes include PVNS and residual scar formation in patients with a history of surgery or trauma. Magnetic resonance imaging (MRI) images are helpful in confirming the diagnosis, however, in a subset of patients, the physician must rely on clinical suspicion and physical exam to make the proper diagnosis. Given the possibility of a false negative MRI images, patients with persistent anterior knee pain with a history of knee surgeries and focal tenderness reproducible on physical exam may benefit from a diagnostic arthroscopy.

Ewings sarcoma of patella: A rare entity treated with a novel technique of extensor mechanism reconstruction using tendoachilles auto graft

We report a case of Ewings sarcoma (ES) involving the patella in a young female. ES of patella is a rare entity. The patient was presented with anterior knee pain and swelling arising from the patella. She was treated with neoadjuvant chemotherapy followed by wide excision of the patella and reconstruction of the extensor mechanism using split tendoachilles auto graft. The patella is an uncommon site for primary or metastatic tumors of the bone. ES, though rare, should be included in the differential diagnosis of swellings arising from the patella. Auto graft from the tendoachilles is a good alternative for reconstructing the extensor mechanism of the knee.

Primary tumors of the patella

The patella is an uncommon location for cancerous occurrence and development. The majority of tumors of the patella are benign, with a significant incidence of giant cell tumors and chondroblastoma. With the development of modern diagnostic technologies, there appear however many other histological types which raise challenges of diagnosis and treatment. In this article, we review the reported histological types of primary patellar tumors. Specifically, epidemiology, symptomatology, imageology, histopathology, and treatment options for these histological lesions will be discussed, respectively. As there is an increasing focus on the diagnosis and the treatment of these lesions, the availability of the integrated information about primary patellar tumors becomes more significant.

Giant cell tumor of the patella: An uncommon cause of anterior knee pain

The patella is a rare site for the development of primary tumors. This is the case report of a giant cell tumor (GCT) occurring in the patella in a 25-year-old woman. The patient presented with a 1-year history of occasional right anterior knee pain. The radiological characteristics suggested a benign condition. The intraoperative pathological diagnosis was GCT of the bone. The lesion was treated by radical curettage with adjuvant therapy comprising phenol and ethanol and injection of calcium phosphate cement. Histologically, the tumor consisted of round or spindle-shaped mononuclear cells admixed with numerous osteoclastic giant cells. The patient was asymptomatic and there was no evidence of local recurrence or distant metastasis 16 months after surgery. Although rare, patellar GCT may be included in the differential diagnosis of anterior knee pain and/or swelling, particularly in young adults.

Anterior knee pain: an unusual presentation of renal cell carcinoma

Metastasis of any kind to the patella is rare. Metastasis to the patella causing symptoms representing the first presentation of underlying malignancy is rarer still. We report the case of a previously fit and well 74-year-old male presenting with left anterior knee pain. The initial diagnosis was osteoarthritis but after continued symptoms a diagnosis of solitary patella metastasis from a primary renal cell carcinoma was confirmed.

Chondroblastoma of the patella with aneurysmal bone cyst

Chondroblastoma of the patella is rare. Aneurysmal bone cysts, which develop from a prior lesion such as a chondroblastoma, are seldom seen in the patella. The authors report a case of a 36-year-old man who presented with 2 years of right knee pain without calor, erythema, pain on palpation, or abnormal range of motion. Radiological studies suggested aneurysmal bone cyst. The lesion was excised with curettage and the residual cavity filled with autogenous bone graft. Histopathology revealed chondroblastoma associated with a secondary aneurysmal bone cyst. In the follow-up period, the patient demonstrated normal joint activities with no pain. Normal configuration of the patella and bone union were shown on plain radiographs. The authors present a review of the literature of all cases of patellar chondroblastoma with aneurysmal bone cyst. This case is the 14th report of aneurysmal bone cyst arising in a chondroblastoma of the patella. According to the literature, computed tomography and magnetic resonance imaging are useful in the study of these lesions. The pathologic diagnosis is based on the presence of chondroblastoma and aneurysmal bone cyst. Treatment of this lesion includes patellectomy, curettage alone, and curettage with bone grafting. Despite the risk of recurrence of this lesion in the patella, the authors first recommend curettage followed by filling the cavity with bone graft. To protect the anterior tension of the patella intraoperatively, the bone window should be made at the medial edge of the patella to perform the curettage and bone grafting.

An uncommon cause of anterior knee pain: patellar chondroma

A 16-year-old boy presented with a patellar mass and anterior knee pain without any trauma. On physical and radiologic assessment, a mass at the superolateral edge of the patella and a hyperintense lesion on T2 sequences of magnetic resonance imaging was detected. Excisional biopsy revealed a chondroma of patella. Primary bone tumors of the patella are extremely rare and occurence of chondroma in this localization is very uncommon. Although anterior knee pain is a very frequent and usually harmless, it is essential to consider the more severe disorders such as bone tumors.

Ewing's sarcoma of the patella

Ewing's sarcoma is a relatively rare malignancy, occurring mainly between 4 and 25 years of age. It usually arises from the pelvis, followed by the femur, tibia, and remainder of both the long bones of the extremities and flat bones of the axial skeleton. To the best of our knowledge, Ewing's sarcoma of the patella has never been reported previously. Patellar tumors occur infrequently and represent an uncommon etiology of anterior knee pain. We describe the rare case of a 41-year-old man who presented with a 3-4 month history of escalating right anterior knee pain and swelling. Imaging demonstrated an aggressive patellar tumor with an adjacent soft tissue mass. The diagnosis of Ewing's sarcoma was confirmed by pathology. Physicians should be aware of atypical locations for Ewing's sarcoma and, conversely, of rare tumors arising in the patella and accounting for anterior knee pain. Early recognition of such malignancies allows prompt initiation of treatment, hence improving prognosis.

[Patellar giant cell tumour: presentation of a case and a review of the literature]

Patellar tumours are rare. They typically appear in young patients, and present with a non-specific pain in the knee. Giant cell tumour (GCT) are benign, but locally aggressive. Although they are usually found around the knee (40-60%), those affecting the patella have been classically described in the literature as uncommon. We describe the case of a 19 year old male complaining of pain in his knee, whose clinical examination suggested a meniscal tear. Plain radiological examination, as well as MRI, revealed a well circumscribed lytic lesion within the patella. The patient underwent arthroscopic surgery, during which an incisional biopsy was performed. Following pathology reports, which confirmed the suspected GCT, definitive surgery was performed. At 56 months after the surgery the patient remains asymptomatic and free of disease.

Imaging tumors of the patella

BACKGROUND

Patellar tumors are rare; only a few series have been described in the literature and radiographic diagnosis can be challenging. We reviewed all patellar tumors at one institution and reviewed the literature.

MATERIALS AND METHODS

In an evaluation of the database at one institution from 1916 to 2009, 23,000 bone tumors were found. Of these, 41 involved the patella. All had imaging studies and microscopic diagnostic confirmation. All medical records, imaging studies, and pathology were reviewed.

RESULTS

There were 15 females and 26 males, ranging from 8 to 68 years old (average 30). There were 30 benign tumors; eight giant cell tumors, eight chondroblastomas, seven osteoid osteomas, two aneurysmal bone cysts, two ganglions, one each of chondroma, exostosis, and hemangioma. There were 11 malignant tumors: five hemangioendotheliomas, three metastases, one lymphoma, one plasmacytoma, and one angiosarcoma.

CONCLUSION

Patellar tumors are rare and usually benign. As the patella is an apophysis, the most frequent lesions are giant cell tumor in the adult and chondroblastoma in children. Osteoid osteomas were frequent in our series and easily diagnosed. Metastases are the most frequent malignant diagnoses in the literature; in our series malignant vascular tumors were more common. These lesions are often easily analyzed on radiographs. CT and MR define better the cortex, soft tissue extension, and fluid levels. This study presents the imaging patterns of the more common patellar tumors in order to help the radiologist when confronted with a lesion in this location.

Osteosarcoma of the patella: a case report

We present a rare case of osteosarcoma involving the patella. A 30-year-old Japanese woman first consulted our out-patient clinic with a 2-year history of knee pain. Radiographs showed an enlargement of the patella with irregular distribution of both osteolytic and sclerotic lesions. Computed tomography and magnetic resonance imaging demonstrated soft tissue extension at the anterior part of the patella. Incisional biopsy showed abundant osteoid formation by spindle-shaped malignant cells, and the histological diagnosis was conventional osteosarcoma. The patient underwent preoperative chemotherapy, but there was no response. Furthermore, she developed a pathological fracture during chemotherapy. She underwent above-the-knee amputation with postoperative chemotherapy. She developed multiple metastases in the thoracic vertebrae 20 months after the surgery. At the most recent examination, she remains alive with multiple spinal metastases without paralysis 4 years after the surgery.

Dorsal defect of the patella with fracture in a teenager

We report the case of a young boy who presented a dorsal defect of the patella (DDP) with fracture after a small sport trauma. The patient's parents (professional of health care) had been warned on a possible tumoral disease in a previous consultation and claimed for an accurate diagnosis. Although fracture is rarely reported in DDP, the radiographic image strongly suggested this condition; nevertheless, the diagnosis accuracy requested by the parents lead to indicate a biopsy that showed irregular fragments of laminar bone and hyaline cartilage islands similar to articular cartilage compatible with a non-specific developmental ossification defect. The lytic defect was filled with morselized cancellous bone graft, the fracture having a normal consolidation. With a follow-up of 4 years, the patient is asymptomatic, and the radiological morphology of the patella is normal. Although DDP is accepted to be a radiologically well-defined condition, images may perhaps not get accuracy enough for diagnosis and biopsy may be indicated by clinical and radiological features different than the typical ones. Although fracture is rarely reported in case of DDP, it has not to be considered as indicative of tumor or malignancy.

Uncommon cause for anterior knee pain - Aggressive aneurysmal bone cyst of the patella

A 56-year-old man presented with a two month history of increasing anterior knee pain without previous trauma. As usual we recommended physiotherapy with stretching exercises of the quadriceps muscle. Since symptoms did not improve after 6 weeks MRI was performed. Surprisingly a hyperintense lobulated mass of the patella with small fluid-filled cavities at the inferior pole was revealed. We performed an open biopsy to exclude any malignancy and diagnosed an aneurysmal bone cyst. Further examination with CT scans showed an aggressive behaviour with cortical breakthrough.

We performed an intralesional curettage with additional high-speed burring and bone cement packing. Sixteen months later the patient was free from any complaints and without signs of local recurrence.

Primary bone tumors of the patella are extremely rare and occurrence of aneurysmal bone cysts in this localization is very uncommon. This case report indicates that although anterior knee pain is a very frequent and usually harmless symptom, it is essential to consider that it might also be caused by more severe disorders such as bone tumors.

Giant cell tumor of the patella and its management using a patella, patellar tendon, and tibial tubercle allograft

Patellar neoplasms are rare. We present a case of aggressive giant cell tumor of patella with extensive involvement of patella and patellar tendon. Its management with wide resection of tumor and reconstruction of extensor mechanism with patella bone tendon allograft is discussed. The patient has good results at 3 years follow-up.

Osteosarcoma of the patella: biologic reconstruction with allograft

Osteosarcoma rarely occurs in the patella. The majority of lesions located in the patella are usually benign. According to the literature, osteosarcoma of the patella has been reported in 32 cases. Surgical treatment (patellectomy, resection and arthrodesis with allograft, and total joint replacement) was attempted in several cases, but neither function of the knee joint nor prognosis of the patients were good. A 53-year-old woman reported pain and swelling in the left knee. Based on plain radiographs and magnetic resonance imaging (MRI), a bone tumor was suspected, and an open bone biopsy of the patella was performed. The pathologic diagnosis was osteoblastic osteosarcoma. A total patellectomy was performed because MRI showed a lesion that did not spread into the joint. A reconstruction was subsequently performed by allograft patella. The graft consisted of a quadriceps tendon, a patella with a patellar tendon, and the medial and lateral retinacula. Twenty-six months postoperatively, the function of the knee joint was almost similar to that before the procedure, and there was no evidence of recurrence or metastasis. After the procedure, the patient could walk without pain and the knee joint could flex to 140 degrees with extension lag of 10 degrees . To our knowledge, this is the first report of a biologic reconstruction with allograft patella after total patellectomy in osteosarcoma involving the patella.

Gastrocnemius muscle flap including Achilles tendon after extensive patellectomy for soft tissue sarcoma

A 72-year-old man developed a soft-tissue sarcoma anterior to his left knee. The tumour was excised widely combined with an extensive patellectomy. A gastrocnemius flap including Achilles tendon was used successfully to cover the soft-tissue defect and to reconstruct the knee extensor mechanism.

Tumour and tumour-like lesions of the patella--a multicentre experience

Fifty-nine cases of lesions presenting in the patella were identified after review of the databases of four European bone tumour registries. Of the 59 cases, 46% were non neoplastic, 39% were benign and 15% were malignant. The commonest benign neoplasm was giant cell tumour (GCT) (11 cases). Younger patients were more likely to have a benign neoplasm. Lesions in patients less than 40 years of age included giant cell tumour, chondroblastoma, aneurysmal bone cyst (ABC), osteomyelitis, osteoid osteoma and solitary bone cyst. In patients older than 40 years, the following were common lesions: intra-osseous gout, metastasis and intra-osseous ganglion. Expansion of the patella with thinning of cortex was seen more commonly in GCT and brown tumour in hyperparathyroidism. There was associated soft tissue extension in gout and malignant lesions.

Iatrogenic seeding of a giant cell tumor of the patella to the proximal tibia

Iatrogenic transplantation of tumor is a rare but avoidable complication, often resulting in additional morbidity or even mortality. We present a case of a 22-year-old woman with a giant cell tumor of the patella initially treated by curettage and bone grafting from the ipsilateral proximal tibia. Local recurrence and tumor growth in the proximal tibia required extensive surgeries. We will discuss the risk of iatrogenic metastasis by direct implantation, often attributable to inadequate surgical planning or poor surgical techniques. The cause and prevention of implantation metastasis are discussed and the basic principles of musculoskeletal tumor management emphasized.

Case reports: Osteogenic sarcoma of the patella spread to lateral meniscus after arthroscopy

Our patient presented with a rare lesion, a patella osteogenic sarcoma that spread to the anterior horn of the lateral meniscus via the arthroscope. He was treated arthroscopically for a torn medial meniscus of his right knee. A lesion in the patella was observed and a biopsy specimen was obtained through the arthroscope. The specimen was diagnosed as an osteogenic sarcoma. After 2 weeks of neoadjuvant chemo-therapy, the patient refused additional chemotherapy. Re-section of the knee and allograft arthrodesis were done 4 months after the initial arthroscopy. Pathologic examination of the resected specimen showed osteogenic sarcoma of the patella and a completely separate 1.0-cm nodule of osteogenic sarcoma tissue growing in the anterior horn of the lateral meniscus. The patient died 15 months after knee re-section with multiple pulmonary metastases. We are unaware that such an occurrence of an osteosarcoma spread through an arthroscope has been documented pathologically and reported.

Giant-cell tumors of the patella

This study describes the clinical, radiographic, and histopathologic features, and discusses the management options of 11 cases of benign giant-cell tumors of the patella seen over 20 years. Fine needle aspiration cytology was a useful preoperative diagnostic tool. Ptellectomy and reconstruction of the extensor apparatus is the favored treatment option with curettage and bone grafting restricted to selected localized lesions.

Patellar tumors

Pain in the anterior knee has become synonymous with patella chondromalacia. However, pain also is the first sign of a tumor of the patella. Tumors of the patella are rare, but they often are mistaken for other benign lesions. Benign tumors of the patella are more frequent than malignant tumors (73% versus 27%). The most common benign neoplasms are giant cell tumor and chondroblastoma. Margin of the lesion, cortical involvement, trabecular pattern, and type of the matrix are important features for a radiographic diagnosis. Bone scans, computed tomography scans, and magnetic resonance images are used for staging of the tumor before surgery. Curettage only should be considered for patients with Stage 1 or Stage 2 benign lesions. Patellectomy is indicated for patients with Stage 3 aggressive benign tumors and for patients with Stage IA malignant tumors. A patellectomy with excision of involved soft tissues is used in patients with Stage IB tumors, whereas in patients with Stage IIA tumors, an extensive patellectomy is indicated. In patients with Stage IIB tumors, an extraarticular resection of the knee is preferred when there is a small soft tissue involvement, but amputation is necessary when there is a large soft tissue mass.

Osteosarcoma of the patella with pulmonary metastases in a dog

A 6-year-old neutered male Rottweiler was examined for a progressive right pelvic limb lameness. In radiographs of the right stifle, there was an osteolytic lesion with irregular new bone formation along the cranial aspect of the patella consistent with an aggressive bone lesion. In thoracic radiographs, there were multiple soft tissue nodular opacities throughout the lung fields, consistent with pulmonary metastases. Microscopically, fine needle aspirate samples from the right patella contained pleomorphic spindle cells with cytologic features of osteosarcoma. The presence of pulmonary metastases at the time of initial diagnosis in the dog described herein suggests that osteosarcoma of the patella has the potential for similar aggressive biologic behavior as that seen in dogs with appendicular osteosarcoma.

Recurrent non-Hodgkin's lymphoma presenting as pathological fracture of the patella

We report a case of recurrent non-Hodgkin's lymphoma presenting as anterior knee pain due to pathological fracture of the patella. Anterior knee pains is an extremely common presenting complaint at orthopaedic clinics and the patella is an infrequent site both for primary and recurrent tumours. This case, treated by patellectomy, illustrates the difficulty of treatment of these lesions and highlights the importance of adequate radiological assessment in sites of previous tumour involvement.

Multicentric osteosarcoma, Rothmund-Thomson syndrome, and secondary nasopharyngeal non-Hodgkin's lymphoma: a case report and review of the literature

PURPOSE

Rothmund-Thomson syndrome (RTS) is an autosomal recessive disease characterized by poikiloderma, photosensitivity, skeletal deformities, and other changes. It is also associated with an increased risk of malignancies, including osteosarcoma. Sixteen previous cases of RTS and osteosarcoma have been reported.

PATIENT

A patient with RTS in whom multicentric osteosarcoma developed is described. After surgery and chemotherapy, a secondary malignant neoplasm (SMN) developed consistent with nasopharyngeal non-Hodgkin's lymphoma.

RESULTS

The patient was treated with anti-CD20 monoclonal antibody and is in complete remission.

CONCLUSION

This is the first report of a patient with RTS treated for osteosarcoma in whom a SMN developed. Potential factors involved in this SMN include genetic predisposition and previous chemotherapy.