Skeletal muscle lymphoma: MRI evaluation

Orofacial intramuscular lymphoma: first presentation

The term lymphoma includes a wide variety of different clinical entities including diffuse large B-cell lymphomas (DLBCL). Skeletal muscle or intramuscular lymphomas represent less than 2% of B-cell Lymphoma, they are quite rare, even more in the orofacial area. We present the case of a painless growing mass of the right cheek mimicking a chronic oral cellulitis in a 34-year-old man. Magnetic resonance imaging (MRI) of the mandible revealed a well-defined 7x3cm mass around the core of the mandible that invades the buccal floor and the subcutaneous planes. A whole-body 18F-FDG PET/CT for the initial diagnosis revealed an intensely isolated hypermetabolic band corresponding to a voluminous tumoral permeation. The diagnosis of a skeletal muscle diffuse large B-cell lymphoma was established after an intraoral biopsy. It was treated with 4 chemotherapy cures and showed complete remission at one year of follow-up. This atypical form of lymphoma should be integrated into the differential diagnosis of soft tissue tumors in the oral cavity.

Primary Soft-Tissue Lymphomas: MRI Features Help Discriminate From Other Soft-Tissue Tumors

OBJECTIVES

MRI presentation of extra-nodal soft-tissue lymphomas (STLs) is scarcely reported and lacks of comparison with other soft-tissue tumors (STTs) including sarcomas (STS). Yet, suggesting this diagnosis on MRI would considerably reduce diagnostic intervals. Our aim was to investigate if conventional MRI could discriminate STLs from other STTs.

METHODS

MRIs of STL patients were compared with those of patients addressed to a sarcoma reference center for the diagnosis of a STT. MRI characteristics depicting the tumor (size, signal, habitats, shape, surrounding tissues) were reported. Uni- and multivariate associations with STL diagnosis were evaluated in the entire cohort, and in the subgroups of benign and malignant STTs patients. Diagnostic performances of MRI features combinations were tested.

RESULTS

We included 39 patients with STLs (median age: 69 years) and 368 patients with other STTs (122 benign STTs and 246 STS; median age: 58 years). Six MRI features were independent predictors of STL compared to all other STTs: intermediate SI on T1-WI, homogeneous enhancement (without necrotic areas), no blood signal, no fibrotic signal, no peritumoral enhancement and lack of abnormal intra- and peritumoral vasculature (p-value range: <0.0001-0.0163). Their simultaneous presence had a sensitivity of 0.88 (0.71-0.96) and a specificity of 0.88 (0.84-0.91). Other relevant MRI features were: no fat signal to discriminate against STS (p = 0.0409), the infiltrative growth pattern and the vessel and nerve encasement to discriminate against benign STTs (p = 0.0016 and 0.0011, respectively).

CONCLUSION

Our research demonstrates that conventional MRI can help discriminating STLs from other STTs. Indeed, radiologists can help suggesting the possible diagnosis of STL, which could speed-up the subsequent proper histopathological analysis in light of MRI findings.

Clinical Presentation and MRI Characteristics of Appendicular Soft Tissue Lymphoma: A Systematic Review

Appendicular soft tissue lymphoma (ASTL) is rare and is frequently misinterpreted as soft tissue sarcoma (STS). Studies investigating magnet resonance imaging (MRI) characteristics of ASTL are scarce and showed heterogenous investigation criteria and results. The purpose of this study was to systematically review clinical presentations and MRI characteristics of ASTL as described in the current literature. For that purpose, we performed a systematic literature review in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Patient demographics, clinical presentation and MRI imaging characteristics of ASTL were investigated, resulting in a total of nine included studies reporting a total of 77 patients. Signal intensity of lymphoma compared to muscle tissue was mostly described as isointense (53%) or slightly hyperintense (39%) in T1-weighted images and always as hyperintense in proton-and T2-weighted images. Multicompartmental involvement was reported in 59% of cases and subcutaneous stranding in 74%. Long segmental involvement was present in 80% of investigated cases. Involvement of neurovascular structures was reported in 41% of cases and the presence of traversing vessels in 83% of patients. The presence of these findings should lead to the inclusion of ASTL in the differential diagnosis of soft tissue masses.

Imaging features of skeletal muscle lymphoma: a case report and literature review

BACKGROUND

Diffuse large B cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma (NHL), occurring predominantly in older people. Skeletal muscle lymphoma is a rare form of DLBCL, most frequently affecting the thigh, upper extremities, calf, and pelvis.

CASE PRESENTATION

We report a case of skeletal muscle DLBCL that was diagnosed using ultrasound (US)-guided biopsy. A 70-year-old man presented with progressive swelling and pain in the left lower extremity and an elevated erythrocyte sedimentation rate (ESR) and serum C-reactive protein (CRP), ferritin, and CA125 levels. US, magnetic resonance imaging (MRI), and computed tomography (CT) showed diffuse lesions in several muscles of the left lower extremity. Positron emission tomography/CT (PET/CT) showed FDG-uptake in the affected muscles. The patient was treated with chemotherapy and achieved a good response. A systematic review of the literature published between 1992 and 2019 was conducted to investigate the role of imaging, including imaging-guided biopsy, in the diagnosis of skeletal muscle lymphoma.

CONCLUSIONS

Skeletal muscle lymphoma is rare. US and MRI features include enlargement of muscular structures, with preservation of the architecture of the tissue and surrounding anatomical structures. Definitive diagnosis relies on histological and immunohistological analysis of a sample obtained through imaging-guided biopsy.

Practice and prospects for PET/CT guided interventions

During the past 10 years, performing real-time molecular imaging with positron emission tomography (PET) in combination with computed tomography (CT) during interventional procedures has undergone rapid development. Keeping in mind the interest of the nuclear medicine readers, an update is provided of the current workflows using real-time PET/CT in percutaneous biopsies and tumor ablations. The clinical utility of PET/CT guided biopsies in cancer patients with lung, liver, lymphoma, and bone tumors are reviewed. Several technological developments, including the introduction of new PET tracers and robotic arms as well as opportunities provided through acquiring radioactive biopsy specimens are briefly reviewed.

[Primary intramuscular non-Hodgkin's lymphoma in young subjects: about a case and review of the literature]

Primary extra-ganglionic non-Hodgkin's lymphoma (NHL) is rare and its primary intramuscular location is exceptional, as it account for less than 0.5% of all patients. It generally affects men, with an average age of 70 years. Standard treatment is based on surgical excision combined with chemotherapy and radiation therapy. We report the case of a 31-year old patient presenting with muscular pseudotumoral syndrome at the level of the right leg. Histological examination showed intramuscular large B-cell non-Hodgkin's lymphoma. The patient underwent exclusive chemotherapy with complete remission.

Unusual Presentation of Angiocentric T-Cell Lymphoma Mimicking Perianal Abscess

Background:

Subcutaneous angiocentric T cell is a common form of cutaneous lymphoma localized within subcutis mimicking lobular panniculitis. It is rarely manifested as perianal skin lesion.

Objective:

To suggest that perianal T-cell lymphoma is a rare entity that should be included in the differential diagnosis of perianal infiltrate mimicking perianal abscess.

Methods and Results:

A 65-year-old woman presented with painful perianal infiltrate mimicking a perianal abscess. The pain lasted seven days and there was no evidence of fever. Bacterial examination of tissue of the infiltrate discovered Staphylococcus aureus. Angiocentric T-cell lymphoma was demonstrated on biopsy.

Conclusion:

Our case represented sequela of subcutaneous angiocentric T-cell malignant lymphoma with a complication of a secondary infection mimicking perianal abscess. In patients presenting with a perianal infiltrate without abscess, a malignant condition should be considered a differential diagnosis and a biopsy should be performed.

Non-Hodgkin's Lymphoma of Multiple Skeletal Muscles Involvement Seen on FDG PET/CT Scans

As normal healthy skeletal muscle does not contain lymphoid tissue, extra nodal lymphoma involving multiple muscles is rare, as well. This study reports a case of non-Hodgkin's lymphoma (NHL) of multiple skeletal muscles involvement and a review of differential diagnosis of it.A 37-year-old female presented to our hospital after being diagnosed with NHL for 7 months. She had received six courses of cyclophosphamide hydroxydaunorubicin oncovin prednisolone etoposide (CHOPE) chemotherapy. Then she felt pain and noticed swelling on her left calf. The fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) image showed abnormal focal FDG uptake in hypo-pharynx, which was the primary NHL and also in multiple groups of muscles in whole body. As the patient has history NHL, lymphoma of multiple muscle involvement was suspected.Finally, an ultrasound-guided tissue biopsy was performed on the left calf and histological examination yielded lymphomatous cells infiltration in the left gastrocnemius.Through this report, we emphasize that a multidisciplinary team approach with clinician, radiologist, and pathologist is essential for proper diagnosis, staging, and management of such rare lesions.

Precursor B-cell lymphoblastic leukemia of the arm mimicking neurogenic tumor: case report

Precursor B-cell lymphoblastic lymphoma (PBLL) is an infrequent subtype of lymphoblastic lymphoma (LBL) that commonly affected site for the diagnosis is the skin, followed by the head and neck. In this report, we presented a special case of PBLL located at the left arm and detected with magnetic resonance imaging (MRI) and ultrasonography (US). This kind of PBLL is similar to a peripheral nerve tumor in clinical and radiographic manifestation.

Grading and characterization of soft tissue tumors on magnetic resonance imaging: the value of an expert second opinion report

Objective

To retrospectively compare the accuracy of the initial MRI (magnetic resonance imaging) report of referring radiologists and the second opinion report.

Material and methods

MRI of 155 patients presenting with a soft tissue tumor (STT) in a single large community center were referred for inclusion in the Belgian Soft Tissue Neoplasm Registry (BSTNR). The initial report and the second opinion report were made independently. Histopathology (gold standard) was obtained in 90 patients (group 1). In 65 patients, the diagnosis was made by the combination of clinical findings and/or follow-up (group 2). In group 1, the concordance in grading and tissue-specific (TS) diagnosis between the referring center (RC) and expert center (EC) was reviewed.

Results

In group 1, MR grading yields a sensitivity of 100% and a specificity of 89% in the EC. The sensitivity was 88% and the specificity 81% in the RC. The accuracy was significantly higher in the EC (92%) compared to the RC (83%) (p = 0.039). The TS diagnosis was correct in 50% versus 38.5% of malignant tumors and in 71.8% versus 51.6% of benign tumors in the EC and RC respectively.

Conclusion

A second opinion report increases the accuracy in the diagnosis of STT on MRI.

Main Messages

• A second opinion MRI report increases the overall accuracy in the diagnosis of soft tissue tumors.

• There is a good overall agreement in MR grading between the referring and expert institution.

• In the expert center, there were fewer false-negative and false-positive diagnoses.

• MRI performs better in the tissue-specific diagnosis of benign versus malignant STT.

MRI features of skeletal muscle lymphoma

OBJECTIVE

The purpose of this study was to assess the MRI findings of skeletal muscle lymphoma.

MATERIALS AND METHODS

MR images of pathologically proven lymphoma of skeletal muscle in 20 patients were retrospectively reviewed for the presence or absence of individual imaging findings. Nine patients had primary muscle lymphoma, and 11 patients had muscle metastasis from systemic lymphoma.

RESULTS

The initial manifestation of skeletal muscle lymphoma was a muscle mass in 15 patients (75%) and abnormal muscle signal intensity in five patients (25%). Muscle enlargement was found in all cases. Long segmental involvement with orientation of the tumor along muscle fascicles was found in 15 patients (75%). Seventeen patients (85%) had traversing vessels within involved muscles. All of the tumors had equal to slightly increased signal intensity compared with normal muscle on T1-weighted images and intermediate signal intensity compared with fat on T2-weighted images. Among the 19 patients who underwent contrast-enhanced imaging, skeletal muscle lymphoma exhibited diffuse homogeneous enhancement in 13 patients (68%), predominantly peripheral thick bandlike enhancement in four patients (21%), and marginal septal enhancement in two patients (11%). Thick irregular enhancement of both deep and superficial fascia was found in 16 patients (84%), and one patient (5%) had deep enhancement only. Subcutaneous stranding was found in 16 patients (80%) and skin thickening in four patients (20%).

CONCLUSION

Skeletal muscle lymphoma has distinctive MRI features that help differentiate it from other soft-tissue tumors and tumorlike lesions.

Lymphoma presenting as a musculoskeletal soft tissue mass: MRI findings in 24 cases

The purpose was to describe the MRI morphological features and signal intensity (SI) characteristics of 24 histologically proven cases of musculoskeletal soft tissue lymphoma presenting clinically as a suspected primary soft tissue sarcoma. This was a retrospective review of clinical notes and MRI studies of 24 patients with a histologically confirmed diagnosis of lymphoma. All patients presented to a specialist orthopaedic oncology unit with a suspected primary soft tissue sarcoma. Features assessed included lesion size and morphology, location, extension across anatomical compartments and signal intensity characteristics. The lesions were predominantly poorly defined with peritumoral oedema in ten cases. All tumours were of intermediate T1W SI, while 85% of lesions also showed intermediate T2W SI. Almost all cases that were located just deep to the fascia showed subcutaneous extension, while 50% had involvement of more than one muscle compartment. In 29% of cases, there was extension of tumour along the neurovascular bundle. Histo-pathologically, 23 lesions were non-Hodgkin's B-cell lymphoma. The MRI features of primary musculoskeletal soft tissue lymphoma include a mass with intermediate SI on T1W and T2W images, involvement of more than one anatomical compartment, subcutaneous extension and extension along the neurovascular bundle.

Malignant lymphoma in skeletal muscle with rhabdomyolysis: a report of two cases

Malignant lymphoma is rarely found in skeletal muscle. In this article, we present two cases of malignant lymphomas that were located in skeletal muscle and caused rhabdomyolysis. One case was a primary skeletal muscle lymphoma (which is quite rare), and the other was a skeletal muscle metastasis of lymphoma. The patient with primary skeletal muscle lymphoma was diagnosed with a diffuse type of non-Hodgkin's lymphoma of T-cell origin, which may be linked to a history of injury. Both patients exhibited diffuse, homogeneous lesions of the affected muscles on computed tomography (CT) and magnetic resonance imaging (MRI). The blood levels of some enzymes and potassium, indicative of rhabdomyolysis, were elevated. Bone scintigraphy depicted widespread, diffuse accumulation of the radioisotope in the affected muscles of both patients, typical of rhabdomyolysis. Rhabdomyolysis may be a sequela of lymphoma, as a result of the tendency of malignant lymphoma to infiltrate diffusely into muscles, to affect multiple neighboring muscle compartments, and to metastasize into other soft tissues, as well as being a sequela of possible cytotoxic or humoral actions, all of which may increase the amount of muscle damage. When a patient presents with diffuse muscle swelling, one should consider a diagnosis of a hematogenous disease, which may cause rhabdomyolysis complicated by renal dysfunction.

Primary anaplastic large cell lymphoma of skeletal muscle presenting with compartment syndrome

We describe a patient with primary anaplastic large cell lymphoma of the forearm presenting with compartment syndrome. Urgent decompression fasciotomy and combination chemotherapy resulted in durable remission status. This is followed by a review of primary skeletal muscle lymphoma in the English literature.

Primary muscle lymphoma

Primary muscle lymphoma is rare. Less than 50 cases have been described. The clinical and radiological features of muscle lymphoma are presented in this series of six cases. Most patients present with solitary or multiple masses which may be painful. Clinical presentation varies from the indolent to the rapidly progressive. Systemic symptoms occur in a minority. In most cases, ultrasound shows an ill-defined hypoechoic mass but apparent coarsening of fibroadipose septa and swelling of muscle bundles may occur. CT shows an iso/hypo dense mass. On MR the mass appears iso/minimally hyperintense to muscle on T1W and enhances, and hyperintense on T2W, proton density and fat suppression sequences. Infiltration of the subcutaneous fat is a striking feature in a majority of cases on CT and MR. The diagnosis can be established by ultrasound guided biopsy and should be performed urgently in HIV positive patients to exclude pyomyositis.

MRI evaluation of diabetic muscle infarction

Diabetic muscle infarction (DMI) is a painful and potentially serious complication in patients with poorly controlled diabetes mellitus. The incidence of DMI is likely much greater than reports in the literature suggest, perhaps secondary to the difficulty in making the diagnosis and excluding other more serious etiologies. This paper describes the role of MRI in the evaluation of a diabetic patient with a painful, swollen limb. Early application of MRI can more accurately classify the disease process and focus the differential diagnosis, thus avoiding the hazards of medical therapy associated with other etiologies such as deep venous thrombosis, cellulitis, or osteomyelitis. This paper describes the evaluation and diagnostic pitfalls encountered in two patients. MRI techniques and applications are presented with a discussion of clinical and radiological differential diagnoses.