Primary and secondary bone lymphomas

Conditional survival of patients with primary bone lymphoma of the spine: how survival changes after initial diagnosis

Background

The current survival prediction methodologies for primary bone lymphoma (PBL) of the spine are deficient. This study represents the inaugural utilization of conditional survival (CS) to assess the outcome of this disease. Moreover, our objective was to devise a CS-based nomogram for predicting overall survival (OS) in real-time for spinal PBL.

Methods

Patients with PBL of the spine diagnosed between January 2000 and December 2015 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. The OS was determined through the Kaplan-Meier method. The CS characteristic of patients with spinal PBL was delineated, with the CS being estimated utilizing the formula: CS(α|β) = OS(α+β)/OS(β). CS(α|β) denotes the probability of additional α-year survivorship, assuming the patient has already survived β years after the time of observation. Three methods including univariate Cox regression, best subset regression (BSR) and the least absolute shrinkage and selection operator (LASSO) regression were used to identify predictors for CS-based nomogram construction.

Results

Kaplan-Meier analysis was executed to determine the OS rate for these patients, revealing a survival rate of 68% and subsequently 63% at the 3-year and 5-year mark respectively. We then investigated the CS patterning exhibited by these patients and discovered the survival of PBL in the spine progressively improved with time. Meanwhile, through three different prognostic factor selection methods, we identified the best predicter subset including age, tumor histology, tumor stage, chemotherapy and marital status, for survival prediction model construction. Finally, we successfully established and validated a novel CS-based nomogram model for real-time and dynamic survival estimation. Moreover, we further designed a risk stratification system to facilitate the identification of high-risk patients.

Conclusions

This is the first study to analyze the CS pattern of PBL of the spine. And we have also developed a CS-based nomogram that provide dynamic prognostic data in real-time, thereby aiding in the formulation of personalized treatment strategies in clinical practice.

Follicular Lymphoma Presenting With Symptomatic Bone Involvement: A Clinicopathologic and Molecular Analysis of 16 Cases

Primary bone lymphoma (PBL) is rare and mostly represented by diffuse large B-cell lymphomas (DLBCL). Follicular lymphoma (FL), albeit commonly disseminating to the bone marrow, rarely presents primarily as bone lesions. Here, we studied 16 patients (12 men:4 women, median age 60 years) who presented with bone pain and/or skeletal radiologic abnormalities revealing bone FL. Lesions were multifocal in 11 patients (spine ± appendicular skeleton), and unifocal in 5 patients (femoral, tibial, or vertebral). An infiltrate of centrocytes and centroblasts (CD20+ CD5- CD10+ BCL2+ BCL6+) with abundant reactive T cells and an increased reticulin fibrosis massively replaced the marrow spaces between preserved bone trabeculae. The pattern was diffuse ± nodular, often with paratrabecular reinforcement and/or peripheral paratrabecular extension. Ki-67 was usually <15%. Two cases had necrosis. BCL2 rearrangement was demonstrated in 14 of 14 evaluable cases (with concomitant BCL6 rearrangement in one). High-throughput sequencing revealed BCL2, KMT2D, and TNFRSF14 to be the most frequently mutated genes. After staging, 5 qualified for PBL (3 limited stage) and 11 had stage IV systemic FL. All patients received rituximab ± polychemotherapy as firstline treatment, and 7 received local therapy (6 radiotherapy and 2 surgery). Three patients experienced transformation to DLBCL. At the last follow-up (15/16, median 48 months), 11 patients achieved complete remission, including all cases with PBL and most patients with limited extraosseous disease (3-year progression-free survival 71%). One patient died of unrelated cause (3-year overall survival 91%). FL may manifest as a localized or polyostotic bone disease. A minority represent PBL, whereas most reveal systemic disease.

Primary Bone Lymphoma of the Spine: A Case Report Highlighting Diagnostic Complexities and Treatment

The diagnosis of primary bone lymphoma (PBL) of the spine is challenging due to its nonspecific symptoms and radiographic features. This report details the case of an 81-year-old female who presented with lower limb weakness and thoracic pain, consequent to a vertebral pathological fracture and spinal cord compression. The initial surgical intervention revealed granulomas with caseous necrosis; however, a definitive diagnosis remained elusive. Following a third surgical procedure and further histopathological examination, the patient was finally diagnosed with diffuse large B-cell lymphoma. The therapeutic course following diagnosis involved chemotherapy, resulting in a marked improvement of the symptoms. Previous studies have highlighted the diagnostic difficulties associated with PBL, reporting the frequent need for multiple biopsies to confirm the diagnosis due to the prevalence of necrosis, crush artifacts, or inadequate sample volume. While PBL of the spine has shown responsiveness to chemotherapy and radiation therapy, early surgical intervention is advocated in cases of severe spinal cord compression or vertebral instability. The presented case highlights the importance of making a definitive pathology diagnosis in cases of suspected PBL of the spine.

Inflammatory Myalgia, A Rare Presentation of Hodgkin's Lymphoma: About a Case

Hodgkin's lymphoma (HL), also known as Hodgkin lymphoma or Hodgkin disease, is a type of malignancy that originates in B lymphocytes, which are a type of white blood cells involved in the immune system. It is characterized by the presence of abnormal Reed-Sternberg cells within the lymph nodes or other lymphoid tissues. Bone involvement of HL is exceptional, which can be localized or part of a disseminated disease. The case of our patient is a Hodgkin's lymphoma initially presenting with a complaint of myalgia. Magnetic resonance imaging and 8F-fluorodeoxyglucose positron emission tomography (FDG PET) played a crucial role in the diagnosis of this rare case.

Rare case of primary bone lymphoma of the femur

Primary bone lymphoma is a rare type of lymphoma that arises from skeletal tissue. Most cases described are non-Hodgkin's lymphoma with diffuse large B-cell lymphoma being the most common subtype. While it is common for non-Hodgkin's lymphoma to have secondary skeletal system involvement, primary involvement of the skeleton is surprisingly rare. Primary bone lymphoma accounts for less than 5% of all primary bone malignancies, 4%-5% of extranodal lymphomas and less than 1% of all non-Hodgkin's lymphoma. We present an interesting case of a young adult male who was diagnosed with primary bone lymphoma of the femur. Interestingly, his initial X-ray imaging revealed no osseous abnormality and subsequent MRI revealed an infiltrating mass. The patient was treated with chemotherapy of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone resulting in complete remission.

Systemic osteosclerosis associated with primary bone marrow B-cell lymphoma

Systemic osteosclerosis is a rare complication of hematological malignancies. Primary myelofibrosis and acute megakaryocytic leukemia are known as underlying diseases; however, lymphoid tumors have rarely been reported. Here we describe a case of a 50-year-old man with severe systemic osteosclerosis associated with primary bone marrow B-cell lymphoma. Analysis of bone metabolic markers revealed a high turnover of bone metabolism and an increase in serum osteoprotegerin levels. These results suggest the involvement of osteoprotegerin in the pathogenesis of osteosclerosis associated with hematological malignancies.

Primary Bone Lymphoma of the Shaft of the Tibia, Mimicking Subacute Osteomyelitis

We present the case of a 32-year-old healthy male who presented with a three-month history of insidious onset pain and swelling over the right tibia. Initial radiographs and imaging pointed to a diagnosis of subacute osteomyelitis, as there was no cortical destruction, periosteal reaction, or soft tissue involvement. The patient underwent surgery for osteomyelitis. However, the histopathology and immunohistochemistry (IHC) findings pointed to a possible B-cell lymphoma diagnosis. The patient was referred to a tertiary-level oncology centre, where a repeat biopsy and positron emission tomography (PET) scan confirmed a diagnosis of primary bone lymphoma (PBL). Treatment was initiated immediately in the form of a combination of chemotherapy and radiotherapy, and the progress was followed up with further scans at four-month intervals. The patient achieved remission nine months after the initiation of treatment.

Role of 18F-fluorodeoxyglucose PET/computed tomography in the diagnosis and treatment response assessment of primary bone lymphoma

OBJECTIVE

Primary bone lymphoma (PBL) is a rare type of extranodal lymphoma, and the clinical application value of 18F-fluorodeoxyglucose PET/computed tomography ( 18 F-FDG PET/CT) in PBL has not been fully evaluated. This study aimed to determine the imaging characteristics of PBL and investigate the value of 18 F-FDG PET/CT parameters.

METHODS

A total of 25 patients with PBL who underwent PET/CT examination before treatment were included in this study. The clinicopathological parameters and PET/CT parameters were analyzed.

RESULTS

Among the 25 patients, 7 patients had single lesions, 15 patients had nonsingle lesions (≥2) and 3 patients had diffuse distribution in the medullary cavity. The bone destruction types included osteolytic, osteogenic, normal density, mixed lytic and osteogenic. All patients showed increased FDG uptake, and the CT detection rate was 88%. Five patients underwent PET/CT assessment mid-treatment, and when assessed using the Deauville five-point scale, four patients were PET-negative and one patient was PET-positive. There were two PET-positive and three PET-negative patients when assessed using the Δ maximum standardized uptake value (SUV max ) method. Six patients underwent PET/CT imaging at the end of treatment. When assessed using the Deauville five-point scale, five patients (83%) were PET-negative and one patient (17%) was PET-positive. The same results were obtained when evaluated by the ΔSUV max method.

CONCLUSION

PET/CT plays a substantial role in the diagnosis and treatment efficacy evaluation of PBL, and it should be recognized by clinicians and radiologists. Changes in metabolic parameters such as SUV, metabolic tumor volume and total lesion glycolysis have considerable potential for application in PBL diagnostics and treatment efficacy evaluation.

Pathological fracture due to primary bone lymphoma in a patient with a history of prostate cancer: A case report and review of literature

Primary bone lymphoma (PBL) is a rare extranodal presentation within lymphomas and primary bone malignancies. Pathologic fracture (PF) is a common complication of metastatic bone disease but is, rarely, the presentation of a primary bone tumor. We report a case of an 83-year-old man with a history of untreated prostate cancer, presenting with atraumatic fracture of his left femur after months of intermittent pains and weight loss. Radiographic workup revealed a lytic lesion suspicious for PF secondary to metastatic prostate cancer; however, initial core biopsy results were inconclusive for malignancy. A complete blood count with differential and complete metabolic panel was within normal limits. During surgical fixation and nailing of the femur, a reaming biopsy was performed as a repeat measure and revealed diffuse large B-cell lymphoma. Staging with positron emission tomography and computed tomography found no evidence of lymphatic or visceral involvement and chemotherapy was promptly initiated. This case highlights the diagnostic workup challenges for PF secondary to PBL, especially in the setting of concurrent malignancy. Because of the non-specific presentation of a lytic lesion on imaging associated with atraumatic fracture, we highlight PBL as an important diagnostic consideration.

Primary Bone Lymphoma: A Review of the Literature with Emphasis on Histopathology and Histogenesis

Primary bone lymphoma (PBL) is a rare neoplasm of malignant lymphoid cells presenting with one or more bone lesions without nodal or other extranodal involvement. It accounts for approximately 1% of all lymphomas and 7% of malignant primary bone tumors. Diffuse large B-cell lymphoma (DLBCL), not otherwise specified (NOS) represents the predominant histological type and constitutes over 80% of all cases. PBL may occur at all ages with a typical diagnosis age of 45–60 years and a slight male predominance. Local bone pain, soft tissue edema, palpable mass and pathological fracture are the most common clinical features. Diagnosis of the disease, which is frequently delayed due to its non-specific clinical presentation, is based on the combination of clinical examination and imaging studies and confirmed by combined histopathological and immunohistochemical examination. PBL can develop in any part of the skeleton, although it occurs most commonly in the femur, humerus, tibia, spine and pelvis. The imaging appearance of PBL is highly variable and unspecific. In terms of the cell-of-origin, most cases of primary bone DLBCL (PB-DLBCL), NOS belong to the germinal center B-cell-like subtype and specifically originate from germinal center centrocytes. PB-DLBCL, NOS has been considered a distinct clinical entity based on its particular prognosis, histogenesis, gene expression and mutational profile and miRNA signature. PBL carries a favorable prognosis, especially when treated with combined chemoradiotherapy.

Bone involvement in primary cutaneous diffuse large B-cell lymphoma, leg-type

Primary cutaneous diffuse large B-cell lymphoma, leg-type (PCDLBCL-LT) is an aggressive cutaneous lymphoma. Bone involvement is rare and poorly described. We present five cases of PCDLBCL-LT with bone localization. In four cases, the bone involvement was diagnosed during the initial staging with positron emission tomography (PET) or computed tomography (CT) scan, and in the fifth case after tibial fracture during treatment with rituximab (RTX) and polychemotherapy (PCT). PCDLBCL-LT can be asymptomatic and involve bone sites distant from cutaneous lesions. None had other extracutaneous involvement. In our series, all patients received RTX-PCT as first-line chemotherapy and all had early relapses or progression. Second-line treatments had poor efficacy. Our series shows that bone involvement seems to be associated with poor prognosis in PCDLBCL-LT. Bone localization is not diagnosed with initial thoracic-abdominal-pelvic CT when asymptomatic and affecting the limbs only. If there is a suspicion of PCDLBCL-LT, patients should undergo systematic investigation with alternative imaging techniques, including PET, both at baseline and if there is any concern during follow-up.

Cranial vault lymphoma - A case report and characteristics contributing to a differential diagnosis

Background

Lymphomas of the cranial vault are rare and are often misdiagnosed preoperatively as presumptive meningioma with extracranial extension.

Case Description

A 58-year-old woman was referred and admitted to our department with a rapidly growing subcutaneous mass over the right frontal forehead of 2 months' duration. The mass was approximately 13 cm at its greatest diameter, elevated 3 cm above the contour of the peripheral scalp, and attached to the skull. Neurological examination showed no abnormalities. Skull X-rays and computed tomography showed preserved original skull contour despite the large extra and intracranial tumor components sandwiching the cranial vault. Digital subtraction angiography showed a partial tumor stain with a large avascular area. Our preoperative diagnostic hypothesis was meningioma. We performed a biopsy and histological findings were characteristic of a diffuse large B-cell lymphoma. A very high preoperative level of soluble interleukin-2 receptor (5390 U/mL; received postoperatively) also suggested lymphoma. The patient received chemotherapy but died of disease progression 10 months after the biopsy.

Conclusion

Several preoperative features of the present case are clues to the correct diagnostic hypothesis of cranial vault diffuse large B-cell lymphoma rather than meningioma, including a rapidly growing subcutaneous scalp mass, poor vascularization, and limited skull destruction relative to the size of the soft-tissue mass.

A 15-Year-Old Boy with Primary Maxillary Bone Anaplastic Lymphoma Kinase-Positive Anaplastic Large Cell Lymphoma Relapsed with Rib Metastasis after Spontaneous Remission of a Maxillary Bone Lesion: A Case Report and Literature Review

Anaplastic large cell lymphoma (ALCL) is a rare form of non-Hodgkin's lymphoma (NHL) in children, accounting for 10-15% of all NHL cases. ALCL is currently classified as follows: systemic anaplastic lymphoma kinase (ALK)-positive, systemic ALK-negative, primary cutaneous, and breast implant-associated ALCL. In children, systemic ALK-positive ALCL is the most common, and patients often present with extranodal involvement. We report a rare case of systemic ALK-positive ALCL with primary bone involvement in a 15-year-old male patient. Primary bone lymphoma is most commonly observed in diffuse large B-cell lymphoma and is extremely rare in systemic ALCL. Therefore, the clinical features and prognosis of primary bone ALCL remain unclear. Our patient had spontaneous remission of primary maxillary bone ALCL after gingival scraping but relapsed 12 months later with rib metastasis. Spontaneous remission of ALCL has been reported frequently in primary cutaneous ALCL and rarely in systemic ALCL. Our case demonstrates for the first time that systemic ALCL can also present as solitary bone involvement that can spontaneously remit. Because systemic ALCL is aggressive and has a risk of relapse, as in our case, it is important to consider ALCL in the differential diagnosis of primary bone lesions and to make a precise pathological diagnosis.

Clinical use of HD-MTX monotherapy in a rare case of refractory primary bone diffuse large B-cell lymphoma with long-term survival after local radiotherapy: A case report

Primary bone diffuse large B-cell lymphoma (PB-DLBCL) has been rarely reported because of its low incidence. The optimal treatment plan for patients with relapsed/refractory PB-DLBCL remains controversial. In this study, we present a case of a 57-year-old patient with refractory PB-DLBCL to better understand this disease. The patient developed lumbosacral/low extremity pain. A lumbar magnetic resonance imaging (MRI) revealed skeletal lesions with osteolysis in L4-L5 and S1. With the failure of multi-line chemotherapy, the patient developed paralysis of both lower limbs. 18-Fluorinefluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) and MRI showed new lesions in the femoral head, cervical and thoracic vertebrae. We tried to treat the patient with adjuvant radiotherapy and 10 courses of high-dose methotrexate (HD-MTX)-based monotherapy, after which the patient was able to walk and achieved complete remission (CR). To the best of our knowledge, this is the first attempt to use local radiotherapy combined with an HD-MTX regimen successfully for the treatment of refractory PB-DLBCL.

Proposal of Diagnostic Approach of Periodontal Primary Non Hodgkin Lymphoma of Bone with Flow Cytometry as an Essential Diagnostic Component

BACKGROUND

Primary bone lymphoma is a rare type of lymphoid neoplasm with favorable prognosis, where Primary Non Hodgkin Lymphoma of bone (PB-NHL) is most common with the subtype. Amongst PB-NHL, diffuse large Bcell lymphoma represents the majority of cases. The mandible is a very uncommon site of involvement, presenting as a painful bone mass with high suspicion of osteomyelitis.

METHODS

We report the case of a 45-year-old male with no significant past medical history who was admitted to the hospital with a large right jaw mass and pain after recent tooth removal. The original tissue biopsy was not diagnostic, and cultures were found to be negative for microorganisms. Due to enlargement of the mass, a fine needle aspiration (FNA) was done. At the time of rapid onsite evaluation of the FNA, atypical lymphoid cells were seen, and material was obtained for flow cytometry (FC) evaluation. This revealed an aberrant clonal B-cell population. The consequent immunohistochemical evaluation of original material supported the diagnosis of PB-NHL. After chemotherapy patient improved.

RESULTS

After an extensive English language literature review, we identified and summarized the clinical presentations, diagnostic procedures, histopathologic features, treatment methods, and outcomes of forty-two cases of periodontal PB-NHL. Based on our findings, we propose a set of clinical features at initial presentation to increase the clinical suspicion of periodontal PB-NHL for practitioners.

CONCLUSION

Based on our institution's experience and the literature review conclusions, we propose the University of Texas Medical Branch diagnostic approach for PB-NHL and suggest that FNA and FC should be utilized as the essential diagnostic component. The fast and efficient diagnosis of PB-NHL can facilitate the correct treatment and sufficiently improve patient care.

Primary Diffuse Large B Cell Lymphoma of Bone: A Single-Center Experience

Background

Primary diffuse large B-cell lymphoma of the bone (PB-DLBCL) is a rare type of extra-nodal lymphoma. This study aimed to examine the clinical characteristics, outcomes, treatment modalities and risk of central nervous system relapse (CNSR) among adult Jordanian patients with PB-DLBCL.

Methods

This retrospective study included patients aged >16 years who were diagnosed with PB-DLBCL and treated at our hospital between 2002 and 2021. Clinical characteristics, treatment modalities, outcomes and CNSR events were extracted from the hospital’s data system and analysed. Patients were categorised into unifocal (UF) and multifocal (MF) PB-DLBCL groups according to the number of bone sites involved. The involvement of only one site was defined as UF, whereas the involvement of two or more sites was defined as MF.

Results

In total, 12 patients were diagnosed with PB-DLBCL. Their median age was 47.5 years (range, 17–80 years). The male:female ratio was 1:1. There were eight patients in the UF PB-DLBCL group and four in the MF PB-DLBCL group. All patients received treatment with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone. In the UF PB-DLBCL group, the male:female ratio was 5:3, the median age was 41 years, and the follow-up duration was 9–135 (mean, 83.3) months. In the MF PB-DLBCL group, the male:female ratio was 1:3, the median age was 51.5 years, and the survival time was 3–11 (mean, 7) months. Three patients with vertebral UF PB-DLBCL underwent early vertebroplasty without complications. The most common site involved was the vertebral column. Most patients with UF PB-DLBCL achieved complete remission (CR), whereas no patients with MF PB-DLBCL achieved CR.

Conclusion

PB-DLBCL is rare in adult Jordanian patients. UF PB-DLBCL is more common than MF PB-DLBCL. Patients with UF PB-DLBCL had a good prognosis. Patients with MF PB-DLBCL had a high international prognostic index score, risk of CNSR and short survival time.

Primary Bone Lymphoma: A Rare Cause of Chronic Back Pain

Primary bone lymphoma is a very uncommon malignancy, which is responsible for 3% of all bone tumors. We report a case of an 80-year-old patient with chronic back pain associated with a pathological T9 fracture. During admission, spinal cord compression with paraparesis was detected and managed with radiotherapy. After investigation, it was discovered to be caused by a primary bone lymphoma. Staging showed multiple bone lesions compatible with polyostotic lymphoma. Histopathology revealed a diffuse large B-cell lymphoma, which was treated with chemotherapy (age-adjusted R-CHOP [rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone] regimen). In this case report, imaging modalities used to diagnose and stage the disease are discussed. Traditional and new prognostic tools and treatment are also reviewed.

Lymphoma in Pediatric-Onset Inflammatory Bowel Disease Treated with Infliximab Monotherapy: A Case Series

BACKGROUND

Inflammatory bowel diseases (IBD) are often treated with anti-tumor necrosis factor alpha (anti-TNFα) medications. Concomitant treatment of IBD with anti-TNFα agents and immunomodulators appears to be associated with an increased risk for lymphoma.

METHODS

Patients who developed lymphoma while on monotherapy with an anti-TNFα agent were identified at three centers. Institutional Review Board approval was obtained.

RESULTS

Five adolescents and young adult patients with pediatric-onset IBD who were treated with infliximab (IFX) without exposure to thiopurines were subsequently diagnosed with lymphoma. Three of the five patients had bone involvement at presentation. Epstein-Barr virus was positive in 2 cases. Median time from diagnosis of IBD and exposure to IFX prior to diagnosis of lymphoma was 5 and 4.3 years, respectively.

CONCLUSIONS

This case series reports long-term follow-up for young patients with IBD who were treated with IFX monotherapy and developed lymphoma. Three of the five patients had bone involvement. In general, the risk of lymphoma following exposure to anti-TNFα medications alone remains low, but the incidence of primary bone lymphomas in IBD has not been reported. Studies examining longer exposure times may be needed to determine the true lymphoma risk in patients treated with IFX monotherapy.

Successful Outcome of Patellectomy Plus Chemotherapy for Primary Bone Lymphoma of the Patella: A Case Report and Literature Review

Primary bone lymphoma (PBL) is a rare but distinct clinicopathological disease, usually occurring in the pelvis, spine, and ribs. To date, only a few cases have been reported as beginning in the patella. Due to the lack of clinical evidence, the optimal treatment strategy has not been established. Here, we report a case that presented unexplained right knee pain. The case was diagnosed with the non-germinal center, diffuse large B cell lymphoma in the patella by imaging examinations and bone biopsy. Then, the patient received a patellectomy and eight cycles of R-CHOP chemotherapy. After treatment, the patient achieved a favorable prognosis and satisfactory functional recovery.

Report of Missed Non-Hodgkin's Lymphoma Presenting as Pathological Tibial Fracture

Pathological fractures usually occur in patients with known malignancies, though pathological fracture may be the first sign of cancer. Malignant pathological fractures most commonly represent metastatic lung, breast, kidney, thyroid, or prostate cancer and typically occur in the spine, pelvis, femur, and humerus. We present the case of a 71-year-old female with an atraumatic tibial fracture in which further imaging was not pursued. Five months later, she was diagnosed with non-Hodgkin’s lymphoma. Pathological proximal tibial fracture is an exceedingly rare presentation of lymphoma; however, diagnostic delay could likely have been avoided if a thorough workup had been pursued. Our case highlights the importance of careful examination of all patients presenting with a low-energy fracture, particularly when constitutional symptoms suggestive of cancer are present. All patients with pathological fractures should receive a thorough physical examination that includes lymph node palpation. 

Spinal Manifestation of Malignant Primary (PLB) and Secondary Bone Lymphoma (SLB)

Manifestation of malignant lymphoma in the spine is rare; there have only been a few cases reported in the literature. Due to its rarity, there is no gold standard for the management of patients suffering from spinal lymphoma manifestations. Methods: We retrospectively reviewed the data for 37 patients (14 female, 23 male) with malignant lymphoma in the spine receiving intervention in our center from March 2006 until June 2020. Neurological impairment, pain, diagnostics, and/or surgical instability were the criteria for surgery in this patient cohort. Otherwise, only CT-guided biopsies were conducted. Analysis of the patient cohort was based on the Karnofsky performance status scale (KPSS), location of the lesion, spinal levels involved, spinal instability neoplastic score (SINS), surgical treatment, histopathological workup, adjuvant therapy, and overall survival. The following surgical procedures were performed: posterior stabilization and decompression in nine patients; decompression and/or tumor debulking in 18 patients; a two-staged procedure with dorsal stabilization and vertebral body replacement in four patients; decompression and biopsy in one patient; a two-stage procedure with kyphoplasty and posterior stabilization for one patient; posterior stabilization without decompression for one patient; a vertebroplasty and cement-augmented posterior stabilization for one patient; and a CT-guided biopsy alone for two patients. Twenty-one patients (56.78%) had ≥1 lesion in the thoracic spine, 10 patients (27.03%) had lesions in the lumbar spine, two patients had lesions in the cervicothoracic junction, two patients had lesions in the thoracolumbar junction, one patient had a lesion in the lumbosacral junction, and one patient had a lesion in the sacrum. The diagnoses of the histopathological workup were diffuse large B-cell lymphoma in 23 (62.16%) cases, indolent lymphoma in 11 (29.74%) cases, anaplastic T-cell lymphoma in one case (2.70%), T-cell lymphoma in one case (2.70%), and Burkitt lymphoma in one (2.70%) case. The median overall survival was 7.2 months (range 0.1–266.7 months). Pre- and postoperative KPSS scores were 70% (IQR 60–80%). Manifestation of malignant lymphomas in the spine is rare. Similar to the approach taken for spine metastases, a surgical intervention in cases of neurological impairment or manifest or potential instability is indicated, followed by chemoimmunotherapy and radiotherapy.

Primary Lymphoma of the Distal Femur Presenting as Spontaneous Deep Vein Thrombosis and Knee Monoarthritis: A Case Report

CASE

A 68-year-old man with a history of unprovoked deep vein thrombosis (DVT) presented with recurrent knee effusions after the initiation of anticoagulation. Radiographs showed soft-tissue swelling without a distinct skeletal lesion. Magnetic resonance imaging, however, showed a marrow-replacing process in the distal femur. Subsequent biopsy demonstrated B-cell lymphoma.

CONCLUSION

This is a rare case of a primary lymphoma of bone mimicking synovial disease. It also highlights the fact that an unprovoked DVT may be a harbinger of an undiagnosed underlying malignancy.

Impact of High-Dose Methotrexate on the Outcome of Patients with Diffuse Large B-Cell Lymphoma and Skeletal Involvement

Diffuse large B-cell lymphoma (DLBCL) with extra nodal skeletal involvement is rare. It is currently unclear whether these lymphomas should be treated in the same manner as those without skeletal involvement. We retrospectively analyzed the impact of combining high-dose methotrexate (HD-MTX) with an anthracycline-based regimen and rituximab as first-line treatment in a cohort of 93 patients with DLBCL and skeletal involvement with long follow-up. Fifty patients (54%) received upfront HD-MTX for prophylaxis of CNS recurrence (high IPI score and/or epidural involvement) or because of skeletal involvement. After adjusting for age, ECOG, high LDH levels, and type of skeletal involvement, HD-MTX was associated with an improved PFS and OS (HR: 0.2, 95% CI: 0.1-0.3, p < 0.001 and HR: 0.1, 95% CI: 0.04-0.3, p < 0.001, respectively). Patients who received HD-MTX had significantly better 5-year PFS and OS (77% vs. 39%, p <0.001 and 83 vs. 58%, p < 0.001). Radiotherapy was associated with an improved 5-year PFS (74 vs. 48%, p = 0.02), whereas 5-year OS was not significantly different (79% vs. 66%, p = 0.09). A landmark analysis showed that autologous stem cell transplantation was not associated with improved PFS or OS. The combination of high-dose methotrexate and an anthracycline-based immunochemotherapy is associated with an improved outcome in patients with DLBCL and skeletal involvement and should be confirmed in prospective trials.

Primary bone anaplastic lymphoma kinase positive anaplastic large-cell lymphoma: A case report and review of the literature

BACKGROUND

Primary bone lymphoma (PBL) is an uncommon extranodal disease that represents approximately 1%-3% of lymphomas. Anaplastic lymphoma kinase (ALK) positive anaplastic large-cell lymphoma (ALCL) is an extremely rare type of PBL. The aim of this report is describe the symptoms, diagnosis, and treatment of primary bone ALK-positive ALCL.

CASE SUMMARY

A 66-year-old man presented to our hospital with neck and shoulder pain and intermittent fever that lasted for 1 mo. After extensive evaluation, positron emission tomography-computed tomography (CT) examination showed multiple osteolytic bone lesions without other sites lesions. CT-guided biopsy of the T10 vertebral body was performed, and the pathology results showed that neoplastic cells were positive for ALK-1, CD30, and CD3. A diagnosis of primary bone ALK positive ALCL was ultimately made. The patient was in partial response after four cycle soft cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy, and we planned to repeat the biopsy and radiological examination after completion of the fifth cycle of therapy.

CONCLUSION

Primary bone ALK positive ALCL is a rare disease and physicians should keep in mind that ALCL can present with isolated osseous involvement without nodal involvement, and lymphoma should be considered in the differential diagnosis of primary bone lesions.

Epiphyseal lymphoid infiltrates of the knee in adolescents

We present three adolescents with focal lesions of the distal femur that were shown to be benign aggregates of small lymphocytes and plasma cells of unknown origin. The patients were within the age of 12 and 14 years. All lesions presented with similar MRI findings and provided the same histopathological findings in the biopsy. Although all lesions increased in size, only one patient remained symptomatic and underwent subsequent tumor resection. To our best knowledge, tumor or pseudotumoral epiphyseal lymphoid infiltrates as seen in these three patients have not previously been described. We recommend a biopsy to rule out a malignant tumor or an infection. Observation, without further invasive testing in asymptomatic patients, is recommended until the resolution of the lesions. However, if a lesion becomes symptomatic, surgical resection should be considered.

[Adult non-Hodgkin bone lymphomas]

Two forms of bone lymphomas can be distinguished: the primary bone lymphoma (PBL) and the secondary bone lymphoma (SBL). PBL is a rare disease with a good prognosis. Clinical manifestations and imaging findings are usually non-specific. Patient can present with pain, swelling of affected bone or pathologic fracture. Positron emission tomography-CT scan is a sensitive imaging modality and very useful for staging, restaging, surveillance of recurrence, and monitoring of treatment response of lymphoma. The diagnosis of PBL is often difficult and made after biopsy examination. Most patients have diffuse large B-cell lymphoma. Patients have been treated with radiotherapy, chemotherapy or combination of both. Localized disease, low IPI (International Prognostic Index) and complete remission after initial treatment were associated with a better outcome. Management of late sequelae deserves particular attention. SBL is more common than PBL; this is a disseminated lymphoma with concomitant involvement of the skeleton. We review the clinical, imaging and pathologic features of bone lymphomas; and discuss therapeutic modalities as well as prognosis of these lymphomas in the era of immunochemotherapy.

Diffuse large B-cell lymphoma mimicking chronic osteomyelitis of the ankle joint: A case report

Lymphoma is the seventh most common type of malignancy in both males and females. It may develop in any location where lymphomatous tissue exists. Although extranodal presentation in the lower limb and pelvis are uncommon, it could present with diverse manifestations. We report an unusual case of primary extranodal large B-cell lymphoma of the ankle joint initially presumed to be a chronic osteomyelitis. This case report discusses the impact of imaging studies on decision-making and highlights the need to consider malignancy in chronic infections.

Radiogenomics and Its Role in Lymphoma

PURPOSE OF REVIEW

Imaging features of lymphoma vary regionally. Awareness of site-specific key imaging characteristics of lymphoma can aid in rapid staging and assist in prompt treatment. FDG PET/CT and conventional MRI are readily available diagnostic modalities with excellent sensitivity and good specificity. Diagnostic specificity can be enhanced using emerging PET radiotracers, e.g., FLT and FET.

RECENT FINDINGS

Emerging research has shown higher dimensional analysis (radiomics and radiogenomics) of imaging data can yield information of the underlying genetic aberrations in lymphoma, which can aid in assessing real-time evolution of tumor. CT, PET/CT, MRI, and ultrasound accentuate the intrinsic qualities of lymphoma (e.g., FDG PET/CT for increased metabolic activity, FLT PET/CT for increased proliferation index, and DWI for increased cellularity) and play an essential role in its diagnosis and examination. Advanced radiogenomic analyses use radiomic parameters to deduce genetic variations of lymphoma, providing noninvasive, repeatable, and real-time surveillance of its genetic progression.

Primary bone lymphoma: pictorial essay

Primary bone lymphoma is a rare neoplasm that can initially present as local pain, a palpable mass, and pathologic fracture. It can also be discovered as an incidental finding on an imaging examination. It is defined as a bone marrow tumor with no involvement of other sites, lasting at least six months. The diagnosis is confirmed by biopsy and immunohistochemical analysis. Although the imaging characteristics are nonspecific, there are certain findings that, when correlated with clinical and epidemiological aspects, can increase the level of suspicion of primary bone lymphoma. The classic imaging aspect is a bone lesion with a soft-tissue component that preserves the cortical layer more than would be expected given the invasive nature of the lesion. Magnetic resonance imaging is the best imaging method to evaluate the extent of involvement of adjacent compartments, whereas computed tomography depicts the cortical layer in greater detail, as well as being an important tool for biopsy guidance. Other imaging modalities are also discussed, such as X-ray, ultrasound, bone scintigraphy, and positron emission tomography/computed tomography. The aim of this paper is to describe the most common findings obtained with the various imaging methods used in patients with a confirmed diagnosis of primary bone lymphoma.

Primary bone lymphoma of the ilium successfully treated without radiation

The addition of radiation therapy to chemotherapy and impact on outcomes in primary bone lymphoma is not clear. Nonetheless, tumor location must be considered as radiation to marrow-rich bone areas can lead to myelosuppression and myelotoxicity.

Primary lymphoma of bone: a population-based study of 2558 patients

Background:

Primary lymphoma of bone (PLB) is an extremely rare malignancy arising in the skeletal system. There is no consensus over the best definition of PLB. Most of the published articles are single-institutional retrospective studies with a limited sample size. The rarity of PLB and discrepancies on diagnostic criteria has resulted in a vague understanding of PLB.

Methods

We retrospectively analyzed the clinical characteristics and prognostic factors of 2558 PLB patients who were registered in the Surveillance, Epidemiology, and End Results (SEER) database from 1973 to 2016. Survival rates were calculated using the Kaplan–Meier method. The effects of various factors on survival outcomes were analyzed by using the log-rank test. Univariate and multivariate analyses were conducted by using the Cox proportional hazards model to determine independent prognostic factors.

Results:

The median follow-up time of all eligible patients was 58 months. There seemed no sex preponderance in PLB incidence. The most involved sites are axial skeletons. The most common histological subtype was diffuse large B-cell lymphoma. The 3-, 5-, 10-, and 20-year overall survival (OS) rates were 70.70%, 65.70%, 54.40% and 39.50%, respectively. PLB patients whose primary tumor sites were appendicular and craniofacial skeletons had a significant survival advantage [hazard ratio (HR) = 0.694, 95% confidence interval (CI) 0.552–0.872; HR = 0.729, 95% CI 0.597–0.889, respectively] over those with axial skeletons as primary tumor sites. Patients with Hodgkin lymphoma, non-Hodgkin lymphoma (NHL)–mature B-cell lymphoma, and NHL-precursor-cell lymphoblastic lymphoma also had a significant OS advantage (HR = 0.392, 95% CI 0.200–0.771; HR = 0.826, 95% CI 0.700–0.973; and HR = 0.453, 95% CI 0.223–0.923, respectively). Patients with Ann Arbor stage III–IV at diagnosis were at higher risk of death than those with stage I–II (HR = 1.348, 95% CI 1.107–1.641). Chemotherapy was an independent favorable prognostic factor (HR = 0.734, 95% CI 0.605–0.890).

Conclusions:

Primary anatomic site, histology type, higher Ann Arbor stage and chemotherapy were independent prognostic factors. Chemotherapy played a pivotal role in PLB treatment.

The incidence and mortality trends of bone lymphoma in the United States: An analysis of the Surveillance, Epidemiology, and End Results database

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The incidence rates of bone lymphoma had sharply increased for the early decades.

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The incidence trend of bone lymphoma has stabilized in recent years.

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The mortality had sharply increased from 1985 to 2016 without a turn point.

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The incidence and mortality by various characteristics had similar patterns.

Background

In recent years, studies on bone lymphoma and its histologic types have reached a mature stage. However, reports on the incidence and incidence-based mortality trends of bone lymphoma are scanty.

Methods

Patients with bone lymphoma in the U.S. were selected from Surveillance, Epidemiology, and End Results (SEER) database (1975–2016), and categorized based on age, sex, race, tumor location, SEER Historic Stage A and histologic type. Data on the incidence (1975–2016) and incidence-based mortality (1985–2016) were directly obtained from the SEER program. Annual percentage change (APC) and 95% confidence intervals (CIs) were calculated using the joinpoint regression analysis program.

Results

Overall, 13,058 bone lymphoma cases diagnosed in resident patients of the U.S. were included in incidence analysis between 1975 and 2016 as follows: 6080 cases in 1975–1999, 3796 cases in 2000–2009, and 3182 cases in 2010–2016. Of these cases, 6888 died of bone lymphoma between 1985 and 2016. The overall incidence rates dramatically increased from 0.89 per 100,000 person-years in 1975 to 1.36 per 100,000 person-years in 2016. Incidence trend sharply increased from 1975 to 2009, and then stabilized between 2009 and 2016. Overall incidence-based mortality trends sharply increased from 1985 to 2016 without a joinpoint. Following the demographic and tumor characteristics, the trends of incidence and incidence-based mortality exhibited similar patterns.

Conclusion

Considering various characteristics (age, sex, race, tumor location, SEER Historic Stage A, and histologic type), we established that the incidence trend of bone lymphoma has sharply been increasing over the decades, however, in the recent years, the trend has stabilized. Besides, between 1985 and 2016, the incidence-based mortality had been sharply increasing without a turning point. These findings could give insights for clinicians to elaborately assess the epidemiology and risk factors of bone lymphoma.

Multiple osteolytic lesions due to Double-Expressor Primary non-Hodgkin Lymphoma of the Bone

Primary non-Hodgkin lymphoma of the bone (PLB) is a rare type of non-Hodgkin’s lymphoma (NHL) that affects the skeletal system with or without regional lymph node involvement. We present the case of a 74-year-old female patient with pain due to multifocal osteolytic lesions. The diagnosis of diffuse large B-cells (non-GCB) phenotype was made by clinical, laboratory, histopathological examination accompanied by an extensive immunohistochemical profile of one of the skeletal lesions.

Primary Bone Lymphoma in Axial Skeleton in a Middle-Aged Female Presented as Recurrent Anemia

Primary bone lymphoma (PBL) is a peculiar extranodal presentation of non-Hodgkin's lymphoma. Primary bone diffuse large B-cell lymphoma (DLBCL) is the most common pathological type, comprising about 80% of PBL. The diagnosis of PBL depends on the combined clinical examination and imaging studies and is confirmed with immunohistochemical examination. Due to the rarity of this disease, more relative studies and case reports are needed to provide insight into this obscure lymphoproliferative malignancy. Here, we report one rare case of primary bone DLBCL involving the axial skeleton in a 37-year-old female.

Primary Bone Lymphoma: A Case Series and Review of Literature

Primary bone lymphoma (PBL) is a subtype of lymphoma that exclusively affects skeletal tissue. Despite the relatively common involvement of skeletal structures as a manifestation of non-Hodgkin's lymphoma (NHL), primary and exclusive involvement of the skeletal system is rare. The prevalence of PBL is estimated to be 3–7% amongst primary bone tumors and less than 2% amongst all lymphomas in adults. However, the definition of primary bone lymphoma has been inconsistent over time. Within our institution, we identified four cases of primary bone lymphoma based on diagnostic criteria formed from the general consensus of multiple organizations, including the World Health Organization (WHO) and International Extranodal Lymphoma Study Group (IELSG). Here, we discuss the distinct characteristics amongst these cases in addition to performing a systematic review of current literature regarding this lymphoproliferative entity.

Imaging mimics of chronic recurrent multifocal osteomyelitis: avoiding pitfalls in a diagnosis of exclusion

Chronic recurrent multifocal osteomyelitis (CRMO) is a pediatric autoinflammatory disorder that is characterized by multiple sterile inflammatory bone lesions with a relapsing and remitting course. CRMO belongs to the autoinflammatory family of rheumatologic disorders based on absence of significant titers of autoantibodies and autoreactive T-lymphocytes. In absence of pathognomonic clinical, radiographic or pathological features, diagnosis can be challenging. CRMO shares imaging features with other diseases. It is important for radiologists to be able to differentiate other diseases from CRMO because prognosis varies from completely benign to frankly malignant. In this article we first present the clinical and imaging features of CRMO to help readers gain an understanding of the disease process, then discuss our imaging approach to CRMO and review other disease processes that sometimes share similar imaging findings to CRMO and review differentiating features to help avoid misdiagnoses.

Primary lymphoma of the tibia in children: Two case reports

RATIONALE

Primary lymphoma of the bones (PLB) is a rare extranodal non-Hodgkin lymphoma (NHL) that is particularly rare in children. The clinical presentation and radiological features of PLB are often nonspecific, making clinical diagnosis challenging and misdiagnosis frequent. Here, we report 2 children with PLB focusing on clinical presentation, differential diagnosis, and treatment outcomes.

PATIENTS CONCERNS

A 9-year-old boy presented with left knee swelling and pain for 4 months after a fall. He was previously misdiagnosed with traumatic soft tissue injury. The second patient was an 11-year-old boy with a 6-month history of intermittent left knee pain. He was previously misdiagnosed with bone tuberculosis and chronic osteomyelitis.

DIAGNOSES

A 9-year-old boy showed an abnormal signal of the left tibia metaphysis, diaphysis, and epiphysis, and tibia with periosteal reactions and surrounding soft tissue swelling. Tumor biopsy and immunohistochemistry confirmed a diagnosis of B-cell lymphoblastic lymphoma.An 11-year-old boy showed a permeative lesion in the metaphysis and diaphysis of the left proximal tibia. Tumor biopsy and immunohistochemistry confirmed the diagnosis of diffuse large B-cell lymphoma.

INTERVENTIONS

Both patients were treated with 6 courses of NHL-Berlin-Frankfurt-Münster-95.

OUTCOMES

Both patients are in complete clinical remission with a follow-up of 27 and 18months after treatment, respectively.

LESSONS

PLB is a rare malignancy that is difficult to diagnose, particularly in children. Clinicians should increase the awareness of the disease and consider a differential diagnosis of bone lesions. Chemotherapy combined with radiotherapy is a favorable treatment for children with PLB. Early diagnosis and active treatment can improve patient prognosis.

Retinal vasculitis with Chronic Recurrent Multifocal Osteomyelitis: a case report and review of the literature

Background

Concurrent presentation of retinal vasculitis with mixed sclerotic and lytic bone lesions is rare.

Case presentation

We present the case of a 37-year old woman with a several year history of episodic sternoclavicular pain who presented for rheumatologic evaluation due to a recent diagnosis of retinal vasculitis. We review the differential diagnosis of retinal vasculitis, along with the differential diagnosis of mixed sclerotic and lytic bone lesions. Ultimately, bone marrow biopsy confirmed diagnosis of chronic recurrent multifocal osteomyelitis (CRMO). Concurrent presentation of CRMO with retinal vasculitis is extremely rare but important to recognize. The patient demonstrated clinical response to prednisone and tumor necrosis factor-alpha inhibition (TNF-i).

Conclusion

This case reports and unusual presentation of CRMO spectrum disease involving the sternum and sternoclavicular joint with concurrent retinal vasculitis.

Beneficial effect of consolidative radiotherapy for patients with lymphoma and skeletal involvement

The objectives of this study were to analyze the clinical features of patients with bone involved lymphoma and identify the prognostic factors and to explore the optimized treatment strategy for bone involved lymphoma.A total of 1948 patients with lymphoma in our cancer center from September 2006 to October 2017 were retrospectively evaluated. Among these, 109 patients with skeletal involvement in lymphoma were enrolled. According to the pathologic subtypes, the patients were divided into 3 subgroups: classic Hodgkin lymphoma (cHL), B-cell non-Hodgkin lymphoma (B-NHL), and T-cell non-Hodgkin lymphoma (T-NHL). The clinical characteristics and overall survival (OS) of 3 groups of patients were reviewed, and the prognostic factors were analyzed.There were 9 (3 unifocal, 6 multifocal) patients with primary bone lymphoma. The 5-year OS of cHL, B-NHL, and T-NHL patients was 88.24%, 54.09%, and 61.58%, respectively. Advanced stage, elevated lactate dehydrogenase (LDH), age above 60, high International Prognostic Index score, and treatment without radiotherapy for the bone involved were significant poor prognostic factors for OS of all patients in univariate analysis. There was a trend toward better OS not only in limited-stage but also in advanced-stage patients with radiotherapy for the bone involved compared with the patients without radiotherapy. Elevated LDH level and age above 60 were the independent unfavorable prognostic factor in multivariate analysis.Elevated LDH level and age above 60 predict the poor prognosis of patients with bone involvement. The potential for long-term survival suggests that additional consolidative radiotherapy for the site of skeleton involvement may have a better chance of long-term success.

Contemporary Management of Appendicular Skeletal Metastasis by Primary Tumor Type

Skeletal metastases exert a profound effect on patients and society, and will be encountered by most orthopedic surgeons. Once a primary malignancy is diagnosed, multidisciplinary management should focus on maximizing the quality of life while minimizing disease- and treatment-related morbidity. This may be best achieved with discerning attention to the unique characteristics of primary cancer types, including pathologic fracture healing rates, longevity, and efficacy of adjuvant therapies. Some lesions may respond well to nonsurgical measures, whereas others may require surgery. A single surgical intervention should allow immediate unrestricted activity and outlive the patient. In certain scenarios, a therapeutic benefit may be provided by excision with a curative intent. In these scenarios, or when endoprosthetic reconstruction is necessary, patients may be best referred to an orthopedic oncologist.

Prognostic Factors Associated With Bone Lymphoma Primarily Presenting in the Spine

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

To determine the prognostic indicators in patients with bone lymphoma of the spine.

SUMMARY OF BACKGROUND DATA

To date, prognosis for patients with spinal bone lymphoma is based on results from small series. Large population-based observational studies are lacking.

METHODS

The Surveillance, Epidemiology, and End Results Registry was used to identify all patients with bone lymphoma of the spine from 1995 through 2014. Overall survival (OS) and disease-specific survival (DSS) estimates were obtained using the Kaplan-Meier method and compared across groups using log-rank test. Association of survival with variables was assessed using Cox proportional-hazards regression analysis. Nomograms were established and validated by R software.

RESULTS

A total of 1338 patients were identified with bone lymphoma of the spine. The trend of incidence was relative steady from 1995 to 2014. The mean and median age of diagnosis was 62.9 and 66.0 years, respectively. Men constituted a slightly greater proportion (55.5%) of the cohort. The most common subtype of lymphoma was diffuse large B-cell lymphoma (59.8%). The 5- and 10-year OS rates for those patients were 60.6% and 44.7%, respectively. Multivariate analysis revealed that age, sex, marital status, and race were sociodemographic predictors of OS and DSS. Extracompartmental invasion of tumor and stage IV of lymphoma were significantly correlated with poor OS and DSS. Patients without surgery or radiotherapy was linked to a poor OS. Both OS and DSS of patients with spinal bone lymphoma improved in 2005 to 2014 when compared to 1995 to 2004. In addition, pretreatment nomograms to predict 5- and 10-year survival were established.

CONCLUSION

The findings of this study provide population-based estimates of the prognosis for patients with spinal bone lymphoma. Both sociodemographic and clinical factors may have an impact on the outcomes.

LEVEL OF EVIDENCE

4.

Epiphyseal Primary Diffuse Large B-Cell Lymphoma of Bone

Primary lymphoma of bone (PLB) confined to the epiphysis has only been described in four other patients. Due to the rarity of this entity, diagnosis has often been delayed, leading to mismanagement with adverse clinical consequences. We report a fifth case of primary epiphyseal lymphoma of bone located in the left distal medial femoral epiphysis of a 13-year-old boy. Radiographic and histologic features of PLB are discussed, along with a review of the literature and pitfalls of misdiagnosis. The patient initially presented with six months of progressive left knee pain with an associated loss of passive range of motion. Imaging revealed a mixed radiolucent lesion within the left distal medial femoral epiphysis with cortical breakthrough. A core biopsy was performed revealing a blue round cell tumor. Thanks to modern immunohistochemistry techniques, a diagnosis of primary lymphoma of bone was quickly made. The patient thus avoided further surgical intervention and received the appropriate treatment of chemotherapy, with subsequent rapid resolution of the lesion. This case highlights the necessity of including primary lymphoma of bone in all epiphyseal lesion differential diagnoses, especially in the pediatric patient population when aggressive radiographic features are present.