MRI of primary non-Hodgkin's lymphoma of the palatine tonsil

Synthetic MRI and diffusion-weighted imaging for differentiating nasopharyngeal lymphoma from nasopharyngeal carcinoma: combination with morphological features

OBJECTIVES

To investigate the feasibility of synthetic MRI (syMRI), diffusion-weighted imaging (DWI), and their combination with morphological features for differentiating nasopharyngeal lymphoma (NPL) from nasopharyngeal carcinoma (NPC).

METHODS

Sixty-nine patients with nasopharyngeal tumours (NPL, n = 22; NPC, n = 47) who underwent syMRI and DWI were retrospectively enrolled between October 2020 and May 2022. syMRI and DWI quantitative parameters (T1, T2, PD, ADC) and morphological features were obtained. Diagnostic performance was assessed by independent sample t-test, chi-square test, logistic regression analysis, receiver operating characteristic curve (ROC), and DeLong test.

RESULTS

NPL has significantly lower T2, PD, and ADC values compared to NPC (all P < .05), whereas no significant difference was found in T1 value between these two entities (P > .05). The morphological features of tumour type, skull-base involvement, Waldeyer ring involvement, and lymph nodes involvement region were significantly different between NPL and NPC (all P < .05). The syMRI (T2 + PD) model has better diagnostic efficacy, with AUC, sensitivity, specificity, and accuracy of 0.875, 77.27%, 89.36%, and 85.51%. Compared with syMRI model, syMRI + Morph (PD + Waldeyer ring involvement + lymph nodes involvement region), syMRI + DWI (T2 + PD + ADC), and syMRI + DWI + Morph (PD + ADC + skull-base involvement + Waldeyer ring involvement) models can further improve the diagnostic efficiency (all P < .05). Furthermore, syMRI + DWI + Morph model has excellent diagnostic performance, with AUC, sensitivity, specificity, and accuracy of 0.986, 95.47%, 97.87%, and 97.10%, respectively.

CONCLUSION

syMRI and DWI quantitative parameters were helpful in discriminating NPL from NPC. syMRI + DWI + Morph model has the excellent diagnostic efficiency in differentiating these two entities.

ADVANCES IN KNOWLEDGE

syMRI + DWI + morphological feature method can differentiate NPL from NPC with excellent diagnostic performance.

Multimodal optical mesoscopy reveals the quantity and spatial distribution of Gram-positive biofilms in ex vivo tonsils

Biofilms are known to be present in tonsils, but little is known about their spatial location and size distribution throughout the tonsil. Studies of the location and distribution of biofilms in tonsil specimens have thus far been limited to either high-magnification methods such as electron microscopy, which enables high-resolution imaging but only from a tiny tissue volume, or lower magnification techniques such as light microscopy, which allow imaging of larger specimens but with poor spatial resolution. To overcome these limitations, we report the use of multimodal optical mesoscopy to visualise and quantify the number and spatial distribution of Gram-positive biofilms in fresh, excised paediatric tonsils. This methodology supports simultaneous imaging of both the tonsil host and biofilms in whole mounts of tissue up to 5 mm × 5 mm × 3 mm with subcellular resolution throughout. A quantitative assessment of 36 tonsil specimens revealed no statistically significant difference between biofilm presence on the tonsil surface and the interior of the tonsil. This new quantitative mesoscale imaging approach may prove useful in understanding the role of biofilms in tonsillar diseases and other infections.

An unusual cause of obstructive sleep apnea syndrome

The histopathologic examination is important after tonsillectomy, irrespective to the surgical indication.

The utility of MRI histogram and texture analysis for the prediction of histological diagnosis in head and neck malignancies

BACKGROUND

To assess the utility of histogram and texture analysis of magnetic resonance (MR) fat-suppressed T2-weighted imaging (Fs-T2WI) for the prediction of histological diagnosis of head and neck squamous cell carcinoma (SCC) and malignant lymphoma (ML).

METHODS

The cases of 57 patients with SCC (45 well/moderately and 12 poorly differentiated SCC) and 10 patients with ML were retrospectively analyzed. Quantitative parameters with histogram features (relative mean signal, coefficient of variation, kurtosis and skewness) and gray-level co-occurrence matrix (GLCM) features (contrast, correlation, energy and homogeneity) were calculated using Fs-T2WI data with a manual tumor region of interest (ROI).

RESULTS

The following significantly different values were obtained for the total SCC versus ML groups: relative mean signal (3.65 ± 0.86 vs. 2.61 ± 0.49), contrast (72.9 ± 16.2 vs. 49.3 ± 8.7) and homogeneity (2.22 ± 0.25 × 10^- 1 vs. 2.53 ± 0.12 × 10^- 1). In the comparison of the SCC histological grades, the relative mean signal and contrast were significantly lower in the poorly differentiated SCC (2.89 ± 0.63, 56.2 ± 12.9) compared to the well/moderately SCC (3.85 ± 0.81, 77.5 ± 13.9). The homogeneity in poorly differentiated SCC (2.56 ± 0.15 × 10^- 1) was higher than that of the well/moderately SCC (2.1 ± 0.18 × 10^- 1).

CONCLUSIONS

Parameters obtained by histogram and texture analysis of Fs-T2WI may be useful for noninvasive prediction of histological type and grade in head and neck malignancy.

MRI of diffuse large B-cell non-Hodgkin's lymphoma of the head and neck: comparison of Waldeyer's ring and sinonasal lymphoma

To document the magnetic resonance imaging (MRI) features of diffuse large B-cell lymphoma (DLBCL) in Waldeyer's ring (WR) and the sinonasal (SN) region, and to identify any differences between lymphatic and extra-lymphatic DLBCLs, and predictors of disease beyond the neck. Primary, nodal, and multifocal sites on head and neck MRI were compared between 31 WR and 15 SN DLBCL, and between 27 patients with disease confined to the head and neck and 16 patients with disease beyond the neck, using logistic regression. Compared to SN, WR DLBCLs had significantly smaller primary tumour volumes (p = 0.009), less deep invasion (p = 0.001), and more nodal disease (p = 0.016). Tumour site (WR vs. SN) was an independent predictor of deep invasion (p = 0.007). Nodal and multifocal diseases were predictors of disease beyond the neck (p = 0.027 and 0.011, respectively). Lymphatic WR DLBCLs were less locally aggressive but had greater propensity to nodal spread than extra-lymphatic SN DLBCLs. Nodal and multifocal diseases predicted disease beyond the neck.

Prognostic CT and MR imaging features in patients with untreated extranodal non-Hodgkin lymphoma of the head and neck region

OBJECTIVE

To determine the prognostic CT and MR imaging features of extranodal non-Hodgkin lymphoma in the head and neck region.

METHODS

The clinical data and CT and MR imaging features of 59 patients with histologically confirmed extranodal non-Hodgkin lymphoma in the head and neck region were retrospectively reviewed. Subjects included 27 male and 32 female patients between 13 and 81 years of age, with a mean age of 60.3 years. The clinical outcomes were categorized according to whether relapse or metastasis occurred within 2 years after therapy. The association between the clinical outcome and radiologic factors including tumour size, margin, shape, local tumour invasiveness, regional lymph node involvement, number of involvement sites, and contrast enhancement patterns was determined using univariate and multiple logistic regression analysis.

RESULTS

Radiologic factors including tumour size, margin, shape, and local tumour invasiveness were associated with poor clinical outcomes, as determined by univariate analysis (P < 0.05). Only the lesion margin category (ill-defined) remained an independent risk factor for clinical outcome in multivariate logistic regression analysis, with an OR of 8.14 (P < 0.05).

CONCLUSION

Ill-defined margin of the primary lesion was indicative of unfavourable survival outcome for patients with extranodal non-Hodgkin lymphoma of the head and neck region.

KEY POINTS

• Tumour size, margin, shape and local tumour invasiveness were prognostically relevant. • Tumour margin was an independent risk factor for clinical outcome. • Ill-defined margin of primary lesion was indicative of unfavourable survival outcome.

Optical coherence tomography and autofluorescence imaging of human tonsil

For the first time, we present co-registered autofluorescence imaging and optical coherence tomography (AF/OCT) of excised human palatine tonsils to evaluate the capabilities of OCT to visualize tonsil tissue components. Despite limited penetration depth, OCT can provide detailed structural information about tonsil tissue with much higher resolution than that of computed tomography, magnetic resonance imaging, and Ultrasound. Different tonsil tissue components such as epithelium, dense connective tissue, lymphoid nodules, and crypts can be visualized by OCT. The co-registered AF imaging can provide matching biochemical information. AF/OCT scans may provide a non-invasive tool for detecting tonsillar cancers and for studying the natural history of their development.

Primary gastrointestinal lymphoma

Gastrointestinal tract is the most common extranodal site involved by lymphoma with the majority being non-Hodgkin type. Although lymphoma can involve any part of the gastrointestinal tract, the most frequent sites in order of its occurrence are the stomach followed by small intestine and ileocecal region. Gastrointestinal tract lymphoma is usually secondary to the widespread nodal diseases and primary gastrointestinal tract lymphoma is relatively rare. Gastrointestinal lymphomas are usually not clinically specific and indistinguishable from other benign and malignant conditions. Diffuse large B-cell lymphoma is the most common pathological type of gastrointestinal lymphoma in essentially all sites of the gastrointestinal tract, although recently the frequency of other forms has also increased in certain regions of the world. Although some radiological features such as bulky lymph nodes and maintenance of fat plane are more suggestive of lymphoma, they are not specific, thus mandating histopathological analysis for its definitive diagnosis. There has been a tremendous leap in the diagnosis, staging and management of gastrointestinal lymphoma in the last two decades attributed to a better insight into its etiology and molecular aspect as well as the knowledge about its critical signaling pathways.

Imaging characteristics of primary laryngeal lymphoma

BACKGROUND AND PURPOSE

The larynx is a rare site for primary NHL. Fewer than 100 cases have been reported in the literature, with the largest imaging review involving only 4 patients. We describe the findings of laryngeal lymphoma on CT, PET, and MR imaging and identify features that may distinguish laryngeal lymphoma from the far more common laryngeal squamous cell carcinoma.

MATERIALS AND METHODS

Multi-institutional retrospective chart review revealed 20 patients with histopathologically proved laryngeal lymphoma. Pretreatment CT, PET, and MR images were reviewed by a head and neck radiologist, focusing on extent of tumor, cervical lymph node involvement, and enhancement patterns.

RESULTS

Patients ranged from 30 to 90 years of age with a mean of 63 years at the time of initial diagnosis and a 2:1 female predominance. The average tumor size was 37 +/- 19 mm. In all patients, laryngeal lymphoma involved the supraglottis but also extended into the glottis (65%) and hypopharynx (60%). The subglottis was less frequently involved (35%). Laryngeal cartilage invasion and cervical lymphadenopathy were each seen in 20% of patients. Lymphoma was consistently FDG-avid (100%) and usually enhanced uniformly with iodinated contrast (73%). Necrosis and calcification were not seen in any cases.

CONCLUSIONS

Although laryngeal lymphoma is rare, particular imaging features suggest this diagnosis. A large uniformly enhancing supraglottic tumor without central necrosis and without cervical lymphadenopathy is a characteristic finding of lymphoma. Similar to squamous cell carcinoma, lymphoma may extend into the subglottis, pharynx, and laryngeal cartilages.

MRI of neck nodes in non-Hodgkin's lymphoma of the head and neck

The aim of this study is to describe the imaging features of neck nodes in non-Hodgkin's lymphoma (NHL). The MR scans of 61 patients undergoing staging of a primary extranodal NHL of the head and neck were reviewed retrospectively. Those MR images with nodal disease were assessed for (a) the pattern of nodal disease, (b) presence of nodal necrosis and (c) presence of extracapsular neoplastic spread (ENS) and nodal matting. The features of the nodal disease were analysed in relationship to the sites of the primary NHL (palatine tonsil (PT) n=23, nasal cavity (NC) n=24, nasopharynx (NP) n=6, other extralymphatic sites (OES) n=8), and histology (natural killer/T-cell (NK/T) n=26, diffuse large cell (DLC) n=24, other subtypes (OS) n=11). Nodal disease was present in 26 patients (43%) and occurred in NHL of the PT n=16 (70%), NP n=3 (50%), NC n=5 (21%) and OES n=2 (25%) and in DLC n=15 (63%), NK/T n=6 (23%) and OS n=5 (45%). Nodal disease was significantly more frequent in DLC than NK/T lymphomas (p=0.0053). Nodal disease spread in a contiguous fashion in 25 (96%) patients with nodes. Necrosis was present in 7 of 26 (27%) being present in DLC of the PT in 5, NK/T of the NP in one and NK/T of the NC in one. ENS and matting were present in 19 (73%) and 13 (50%) patients with nodes, respectively. ENS was found in DLC, NK/T, OS, NC, NP, PT, OES (11, 4, 4,1, 2, 14, 2, respectively) and matting was found in DLC, NK/T, OS, NC, NP, PT, OES (9, 3, 1, 0, 2, 10, 1, respectively). Nodal NHL spreads in a contiguous fashion and is most commonly associated with DLC lymphoma of the NP and PT in Waldeyer's ring. Extracapsular nodal spread is frequent and found in most histological subtypes especially those arising from Waldeyer's ring. Necrosis is more common than previously believed.

The value of dynamic contrast-enhanced MRI in diagnosis of malignant lymphoma of the head and neck

In this study, we attempted to diagnose malignant lymphoma on the basis of magnetic resonance imagings (MRIs) and dynamic contrast-enhanced MRI (DCE-MRI). Eighteen lesions (in eight patients), all of which had been proven histopathologically, were detected on MRI. The eight patients included five patients with diffuse large B-cell lymphoma, one with B-cell low-grade MALT lymphoma, one with follicular lymphoma, and one with Hodgkin's lymphoma. Nine lesions were located in the submandibular region, three in the buccal region, two in the orbit region, two in the submental region, and one each in the palatal and tonsil regions. The diameter of the lesions ranged between 9 and 42.2 mm (average: 22.4 mm). The signal intensities (SIs) of the 18 lesions were examined on T1-weighted (T1WI), T2WI, and gadopentetate (Gd)-T1WI. One lesion in case 8 was excluded from DCE-MRI findings, i.e., the regions of interest could not be adequately set on DCE-MRIs. The contrast index (CI) curves of the remaining 17 lesions were prepared. All 18 lesions showed almost the same images on T1WI, T2WI, and Gd-T1WI, although they represented four types of lymphoma. The images showed homogeneous SI that was intermediate to slightly high SI on T1WI, slightly high SI on T2WI, and moderately enhanced on Gd-T1WI. Thus, the cases of malignant lymphoma in this study showed relatively characteristic features based on MRI; however, these features might be non-specific. The CI curves in this study showed a relatively rapid increase, reaching a maximum CI at 45-120 s, and a relatively rapid decrease in most lesions (14/17; 82.4%); on the other hand, the curves of 3 of the 15 lesions (17.6%) showed relatively rapid increase, sustenance of a plateau, and a gradual decrease thereafter. These patterns of CI curves may indicate characteristic features useful for distinguishing malignant lymphomas from other lesions.