MRI features of different types of sinonasan rhabdomyosarcomas: a series of eleven cases

OBJECTIVE

To retrospectively analyze magnetic resonance imaging (MRI) features of various pathological subtypes of sinonasal rhabdomyosarcoma (RMS) and explore correlations between imaging features and pathological subtypes.

METHODS

In total, 11 cases with embryonal, alveolar or pleomorphic sinonasal RMSs, confirmed by surgical pathology, were selected. Their characteristics and distinctive imaging features were analysed, and the correlation between pathology and imaging features was explored.

RESULTS

Bone destruction was observed in all 11 cases with RMS. Expansive growth was predominant in three alveolar and three embryonal RMS cases, and creeping growth was predominant in two alveolar, two embryonal and one pleomorphic RMS cases. Signs of residual mucosa were observed in all 11 cases, and 10 cases showed involvement of multiple sinus cavities and orbital cavities. All cases exhibited mild-to-intermediate enhancement.

CONCLUSION

Sinonasal RMSs have the following characteristic MRI features: ethmoid sinuses and middle nasal conchae are the prevalent sites; lesions are mainly of mild enhancement; tumours exhibit signs of residual mucosa, mild-to-intermediate enhancement and frequent orbital involvement; bone invasion and bone destruction are frequently observed; and haematogenous metastasis is not as common as lymphatic metastasis. RMSs of various pathological subtypes were not significantly distinct by imaging.

Comparison of CT features of 79 cats with intranasal mass lesions

Objectives

This retrospective multicentre study compared the CT characteristics of cats diagnosed with intranasal mass lesions to determine if defining imaging features exist between different tumour types and between neoplastic and non-neoplastic lesions.

Methods

The medical records of two institutions were reviewed for cats with CT findings consistent with an intranasal mass lesion with subsequent histopathological examination. For each CT scan the mass location, growth pattern, margin distinction, contrast enhancement pattern and presence of intralesional areas of mineralisation or necrosis were recorded. The presence of facial deformity, the location and type of bone changes, extranasal extension of the mass lesion and the regional lymph nodes size, contrast pattern and hilus visibility were also documented.

Results

Thirty-five cats with nasal lymphoma, 28 cats with non-lymphomatous nasal neoplasia (carcinoma or sarcoma) and 16 cats with inflammatory lesions met the inclusion criteria. Cats with non-lymphomatous nasal neoplasia were more likely to show unilateral nasal changes (odds ratio [OR] 3.9), areas of intralesional calcification (OR infinity) and extension of the mass lesion within the frontal sinus (OR 4.5), while cats suffering from nasal lymphoma were more likely to show a mixed (OR 4.5) and expansile growth pattern (OR 7.8), and a regional lymphadenomegaly (OR 2.4). The CT findings in cats diagnosed with inflammatory mass-like lesions were highly variable and overlapped with findings for nasal neoplasms but were significantly associated with the absence of bony changes to the nasal cavity boundaries (OR 10.2).

Conclusions and relevance

Findings from the current study support the ability of CT to aid in the discrimination of tumour type in cats presented with an intranasal mass lesion.

Differential Diagnosis of Sinonasal Lymphoma and Squamous Cell Carcinoma on CT, MRI, and PET/CT

Objective The purpose of this study was to analyze computed tomography (CT) and magnetic resonance (MR) images and to evaluate the maximum standardized uptake value (SUV max) of positron emission tomography (PET)/CT parameters between sinonasal non-Hodgkin's lymphoma (NHL) and squamous cell carcinoma (SCC), knowing the imaging features that distinguish sinonasal NHL from SCC. Study Design Case series with chart review. Setting University tertiary care facility. Subjects and Methods We analyzed the features on CT, MR imaging, and PET/CT of 78 patients diagnosed with sinonasal NHL or SCC histopathologically. The CT (n = 34), MRI (n = 25), and PET/CT (n = 33) images of 39 patients with sinonasal NHL and the CT (n = 38), MR (n = 28), and PET/CT (n = 31) images of 39 patients with SCC were evaluated. The sinonasal NHL was diagnosed as natural killer/T-cell lymphoma (n = 28) and diffuse large B-cell lymphoma (n = 11). Results Patients with sinonasal NHL had a larger tumor volume and higher tumor homogeneity than patients with SCC on T2-weighted and postcontrast MR images. Most of the sinonasal NHL and SCC showed a high degree of enhancement. The apparent diffusion coefficient (ADC) values and adjacent bone destruction were significantly lower in sinonasal NHL than in SCC. However, cervical lymphadenopathy, Waldeyer's ring involvement, and PET/CT SUV max showed no significant differences between sinonasal NHL and SCC. Conclusion CT and MR images of sinonasal masses showing a bulky lesion, marked homogeneity, and low ADC values without adjacent bone destruction are more suggestive of sinonasal NHL than SCC.

Imaging Characteristics of Malignant Sinonasal Tumors

Malignancies of the nasal cavity and paranasal sinuses account for 1% of all malignancies and 3% of malignancies of the upper aerodigestive tract. In the sinonasal tract, nearly half of all malignancies arise in the nasal cavity, whereas most of the remaining malignancies arise in the maxillary or ethmoid sinus. Squamous cell carcinoma is the most common histological subtype of malignant tumors occurring in this area, followed by other epithelial carcinomas, lymphomas, and malignant soft tissue tumors. Although many of these tumors present with nonspecific symptoms, each tumor exhibits characteristic imaging features. Although complex anatomy and various normal variants of the sinonasal tract cause difficulty in identifying the origin and extension of large sinonasal tumors, the invasion of vital structures such as the brain, optic nerves, and internal carotid artery affects patients’ prognosis. Thus, diagnostic imaging plays a key role in predicting the histological subtype and in evaluating a tumor extension into adjacent structures. This article describes the computed tomography and magnetic resonance imaging findings for malignant sinonasal tumors.

Differentiation of extranodal non-Hodgkins lymphoma from squamous cell carcinoma of the maxillary sinus: a multimodality imaging approach

This study aimed to assess the efficacy of a multimodality imaging approach for differentiating between primary extranodal non-Hodgkin’s lymphoma (NHL) and squamous cell carcinoma (SCC) of the maxillary sinus. Twelve NHLs and 29 SCCs of the maxillary sinus were included. CT findings, MR signal intensities, apparent diffusion coefficients (ADCs), and maximum standardized uptake values (SUVmax) were correlated with two pathologies. On CT, permeative growth frequency was greater among NHLs than among SCCs (50 % vs. 10 %; p < 0.01), whereas destructive growth frequency was greater among SCCs than among NHLs (83 % vs. 33 %; p < 0.01). On CT, remaining sinus wall within the tumor was more frequent with NHLs than with SCCs (92 % vs. 34 %; p < 0.01), whereas intratumoral necrosis was more frequent with SCCs than with NHLs (86 % vs. 17 %; p < 0.01). ADCs were lower for NHLs than for SCCs (0.61 vs. 0.95 × 10^–3 mm²/s; p < 0.01). No significant differences in MR signal intensities and SUVmax were observed. Tumor growth pattern, remaining sinus wall within the tumor, and intratumoral necrosis were useful CT findings for differentiating between NHLs and SCCs. ADC measurements could assist the differentiation of NHL from SCC.

Bone and soft tissue non-Hodgkin lymphoma of the maxillofacial area: report of two cases, literature review and new therapeutic strategies

Primary mandibular non-Hodgkin lymphoma (NHL) and soft tissues NHL of the maxillofacial are extremely rare representing a minimal percentage of the head and neck tumors. Two cases of bone and soft tissue maxillofacial NHL are reported. Clinical, radiological and pathological features are described and the therapeutic procedures are discussed accordingly. Mandibular radiologic features have been carefully analyzed and discussed to achieve an early and accurate diagnosis avoiding improper dental therapies.

MRI of lymphomas of the orbits and the paranasal sinuses

PURPOSE

The purpose of this study was to point out MR characteristics of non-Hodgkin lymphomas of the orbits and the paranasal sinuses and the benefit of fat-suppressed contrast-enhanced sequences.

METHOD

The MR images of 16 patients with lymphoma of the orbits and the paranasal sinuses were retrospectively analyzed for signal intensity, contrast enhancement, bone destruction, and mass effect. The findings were confirmed by means of biopsy (Stage IE disease) or follow-up imaging after chemotherapy (Stage IV disease).

RESULTS

MRI clearly delineated the extension of the lymphomas. On the T1-weighted images, the signal intensity of the lymphoma was hypointense compared with the gray matter of the brain in 12 cases and intermediate in 4 cases. The T2-weighted fast SE images showed a hyperintense signal in 12 cases, intermediate in 3 cases, and even hypointensity in 1 case. All lesions enhanced after intravenous Gd-DTPA administration, reliably visible in the T1-weighted fat-suppressed sequences but not visible in three cases in the T1-weighted SE sequences. Bony wall destruction was evident in cases with paranasal but never in isolated orbital lymphoma.

CONCLUSION

While extension of lymphoma can be accurately described by MRI, a specific diagnosis is not achievable on the basis of signal intensities and enhancement patterns alone. Therefore, at least in cases of suspected Stages IE and IIE, biopsy proof is needed. Fat-suppressed contrast-enhanced sequences possess the highest detection rate and should therefore always be applied.

Primary non-Hodgkin's lymphoma of the maxillary sinus

Primary non-Hodgkin's lymphoma of the maxillary sinus is a rare lesion. We studied nine patients with malignant lymphoma involving the maxillary sinus, treated between 1980 and 1994 in the Kyushu University Hospital. All lymphomas had a diffuse pattern; five were the large-cell type, two the mixed type, and one the small lymphatic and small cleaved type. Immunohistologically, all tumors were B-cell type. Using the Ann Arbor staging system, six patients were classified as stage I, two stage II, and one stage IV. Two patients received only radiotherapy because of advanced age; the remaining seven received a combination of radiotherapy and chemotherapy (CHOP or VEPA). The tumor doses ranged from 30 to 51 Gy (mean, 46.7). The mean follow-up was 51 months. Only one patient (stage IV) died of disease, and eight stage I-II patients were rendered disease-free. The 5-year survival rate was 80%, suggesting that primary lymphoma of the maxillary sinus has a relatively good prognosis.