Non-Hodgkin lymphoma involving the parotid gland: CT and MR imaging findings

Linfoma MALT de glándula parótida. Descripción de un caso

Introducción y objetivo: Los linfomas de la glándula parótida son una entidad infrecuente. Presentamos un caso clínico de linfoma tipo MALT de parótida, describiendo sus métodos diagnósticos y de tratamiento más empleados. Descripción: Mujer de 69 años con tumoración asintomática en cola de parótida y visión de estructuras nodulares en imagen de TC y RM con PAAF negativa. Se realiza parotidectomía total hallando el diagnóstico de linfoma MALT de la zona marginal. Se completa tratamiento mediante esquema R-CHOP durante 4 meses, sin signos de recidiva al año. Discusión: El linfoma tipo MALT es un tipo de LNH relacionado principalmente con inflamación autoinmune crónica en el caso de aparición sobre glándulas salivales. Se presenta como una tumoración asintomática e inespecífica de crecimiento lento y se diagnostica mediante TC o RM en su mayoría de casos. El tratamiento se realiza mediante parotidectomía asociado a quimioterapia y/o radioterapia, con una tasa de supervivencia mayor al 80% en 5 años. Conclusiones: Los linfomas de glándulas salivales son poco habituales y ocasionalmente se diagnostican de manera inadecuada debido a su comportamiento benigno que mimetiza a tumores más familiares del área parotídea. Su sospecha y distinción son esenciales y no deben olvidarse en nuestro diagnóstico diferencial de masas parotídeas.

Efficacy of Surgery in Patients with Stage I Primary Parotid Gland Lymphoma: A Population-Based Study

Background. Limited and controversial evidence is available on the efficacy of surgery for patients with stage I primary parotid gland lymphoma. Thus, we aimed to investigate whether surgery can enhance the prognosis of patients with stage I primary parotid gland lymphoma using large sample data. Methods. From 1998 to 2015, we searched the Surveillance, Epidemiology, and End Results (SEER) program database and extracted information regarding patients with stage I primary parotid gland lymphoma; we classified these patients into surgery and nonsurgery groups. We calculated overall survival (OS) and cancer-specific survival (CSS) using Kaplan–Meier curves and log-rank testing. Propensity score matching (PSM) analysis was also used to further account for confounding variables before comparing the OS and CSS again. We used the COX proportional hazard regression model in both multivariate and univariate analyses. Results. We enrolled 918 patients with stage I primary parotid gland lymphoma, among which 656 (71.5%) patients underwent surgery. Before PSM, the surgery group had better OS (hazard ratio (HR) = 0.673, 95% confidence interval (CI): 0.519–0.873, and $p=0.003$ ) and CSS (HR = 0.595, 95% CI: 0.403–0.879, and $p=0.008$ ) than the nonsurgery group. After PSM, surgery was still a beneficial factor for OS (HR = 0.569, 95% CI: 0.399–0.810, and $p=0.002$ ) and CSS (HR = 0.384, 95% CI: 0.220–0.669, and $p=0.001$ ). Furthermore, in univariate and multivariate analyses, total parotidectomy significantly increased OS ( $p=0.001$ and $p=0.021$ , respectively) and CSS ( $p=0.001$ and $p=0.037$ , respectively). Conclusions. In summary, the prognosis of patients with stage I primary parotid gland lymphoma can be significantly improved by surgery. Moreover, total parotidectomy was a protective factor for OS and CSS before and after PSM analysis, suggesting that surgery acts as a significant component in multimodal therapy for early primary parotid gland lymphoma.

Magnetic resonance imaging of parotid gland tumors: a pictorial essay

Imaging of parotid gland tumors is challenging due to the wide variety of differential diagnoses. Malignant parotid tumors can have very similar features to benign ones, such as slow growth and displacement instead of infiltration of neighboring structures. Malignant and benign tumors may therefore not be clinically distinguishable. Correct characterization of parotid tumors (i.e., benign or malignant) determines preoperative treatment planning and is important in optimizing the individualized surgical plan. Magnetic resonance imaging (MRI) is the imaging modality of choice for evaluation of suspected parotid gland lesions and differentiation between benign and malignant lesions. Certain conventional MRI features can suggest whether a mass is more likely to be a benign or low-grade malignancy or a high-grade malignancy and adding diffusion-weighted imaging or advanced MRI techniques like perfusion can aid in this distinction. Morphological features seen on MRI, such as low signal on T2-w, infiltrative changes or ill-defined margins, change over time and diffusion restriction can point to the malignant nature of the lesion. MRI is useful for detection and localization of the lesion(s), and associated findings like perineural spread of tumor, lymph node involvement and infiltrative changes of the surrounding tissues. In this pictorial essay, we present selected images of a variety of benign and malignant parotid tumors and emphasize the MRI features that may be useful in their characterization.

Predisposing Factors, Clinical Picture, and Outcome of B-Cell Non-Hodgkin’s Lymphoma in Sjögren’s Syndrome

Among other systemic autoimmune diseases, primary Sjögren syndrome (pSS) bears the highest risk for lymphoma development. In pSS, chronic antigenic stimulation gradually drives the evolution from polyclonal B-cell expansion to oligoclonal/monoclonal B-cell predominance to malignant B-cell transformation. Thus, most pSS-related lymphomas are B-cell non-Hodgkin lymphomas (NHLs), with mucosa-associated lymphoid tissue (MALT) lymphomas predominating, followed by diffuse large B-cell lymphomas (DLBCLs) and nodal marginal zone lymphomas (NMZLs). Since lymphomagenesis is one of the most serious complications of pSS, affecting patients’ survival, a plethora of possible predisposing factors has been studied over the years, ranging from classical clinical, serological, hematological, and histological, to the more recently proposed genetic and molecular, allowing clinicians to timely detect and to closely follow-up the subgroup of pSS patients with increased risk for lymphoma development. Overall predisposing factors for pSS-related lymphomagenesis reflect the status of B-cell hyperactivity. Different clinical features have been described for each of the distinct pSS-related B-cell NHL subtypes. While generally pSS patients developing B-cell NHLs display a fairly good prognosis, outcomes in terms of treatment response and survival rates seem to differ depending on the lymphoma subtype, with MALT lymphomas being characterized by a rather indolent course and DLBCLs gravely affecting patients’ survival.

Imaging characteristics of Sjögren's syndrome

The current workup of Sjögren's syndrome is based on diagnostic criteria involving a combination of histology, immunology, ophthalmology, and salivary flow. Several modern imaging techniques provide complementary and additional information to diagnosis, staging, and surveillance. In this review article, we discuss the characteristic salivary imaging findings seen with the most commonly utilized imaging modalities. We also discuss imaging findings of the central nervous system disorders associated with Sjögren's syndrome, including the neuromyelitis optica spectrum disorder, and provide a differential diagnosis of alternative etiologies that can mimic Sjögren's syndrome.

Biomarkers of lymphoma in Sjögren's syndrome: what's the latest?

INTRODUCTION

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease standing in the crossroads of autoimmunity and lymphomagenesis, characterized by chronic B-cell hyperactivity and ectopic lymphoid tissue neoformation, potentially driving lymphoid malignant transformation. Lymphoma development is considered the most serious complication of pSS.

AREAS COVERED: “

Old-classical" biomarkers (clinical, serological, hematological, and histological) validated in the past are analyzed under the perspective of recently published research. Biomarkers that have emerged during the last decade are subdivided to "old-new" and "newly proposed-novel" ones, including biomarkers pathophysiologically related to B-cell differentiation, lymphoid organization, and immune responses, identified in serum and tissue, both at genetic and protein level. Upcoming new imaging biomarkers, promising for further patient stratification, are also analyzed.

EXPERT OPINION

Salivary gland enlargement and cryoglobulinemia still remain the best validated "classical-old" biomarkers for lymphoma development. Though new biomarkers still need to be validated, some can be used for the identification of high-risk patients long before lymphoma diagnosis, some might be more relevant in distinct age subgroups, while others have an added value in the assessment of lymphoma remission or relapse. Future development of composite indices integrating old and recently proposed biomarkers could contribute to a more precise lymphoma prediction model.

Imaging Features of Lymphoepithelial-Like Carcinoma of the Salivary Glands

OBJECTIVE

Lymphoepithelial-like carcinoma of the salivary glands (LELCSG) is a rare tumour of unknown aetiology. No studies have reported the imaging features of primary LELCSG.

METHODS

The clinical information and imaging features of eight patients with LELCSG were reviewed. Computed tomography (n = 4 patients) and magnetic resonance imaging (n = 4 patients) features were analysed by two radiologists to identify the location, number, size, shape, boundary, signal intensity and enhancement of LELCSG.

RESULTS

The study included four women and four men, and the mean size of the tumours was 32.88 ± 3.41 mm (range, 27-38 mm). The tumours affected the parotid gland in six cases and the submandibular gland in two cases. The eight cases were evaluated by radiologists. All tumours were lobulated; three had clear edges and five had blurred edges. There was no necrosis in six tumours, while two tumours exhibited slight necrosis without bleeding. All eight tumours showed multiple nodular changes and extensive fusion. Four tumours with magnetic resonance imaging (MRI) were isointense or slightly hyperintense on T1-weighted imaging (T1WI) and obvious homogeneous enhancement on contrasted enhanced T1WI scan, while slightly hyperintense on T2-weighted imaging (T2WI). The other four lesions were isodense on computed tomography (CT) scan. The degree of enhancement varied among the eight tumours. The necrotic zones of the eight tumours did not exhibit any enhancement.

CONCLUSIONS

LELCSG is a lobulated, multi-nodular tumour, with some fused nodules. LELCSG lesions showed isointensity or slight hyperintensity on T1WI MRI, slight hyperintensity on T2WI MRI and isodense on CT scan. Larger tumours may exhibit some necrosis, but the necrotic cysts were relatively rare. Uniform enhancement was observed in non-necrotic areas on enhanced CT and MRI scan. The multi-nodular feature may be valuable for diagnosis.

Primary non-Hodgkin lymphoma of the parotid gland: a case report

Most malignant lymphomas of the head and neck region are non-Hodgkin lymphomas (NHL), and diffuse large B-cell lymphoma is the most common subtype. The prevalence of malignant lymphoma among parotid tumors is low, approximately 1% to 4%. The most common symptom of parotid lymphoma is a unilateral, non-tender, firm mass that slowly grows in size over time. As its clinical manifestations are non-specific, a comprehensive assessment is required for an accurate diagnosis. The initial work-up includes imaging tools, such as computed tomography and magnetic resonance imaging. However, NHL of the parotid gland is difficult to distinguish from other types of benign tumors prior to biopsy; histopathological evaluation and subsequent immunohistochemical staining are needed for the final diagnosis. Once a definitive diagnosis is established, patients should be referred to an oncologist for staging. Treatment is mainly based on systemic chemotherapy, whereas radiotherapy is indicated for certain cases. Here, we report the case of a 53-year-old man who presented with a progressively enlarging mass in the right parotid area, which was later diagnosed as malignant lymphoma of the parotid gland after superficial parotidectomy.

MR Imaging of Salivary Gland Tumors

Neoplasms of the salivary glands are characterized by their marked histologic diversity giving them nonspecific imaging findings. MR imaging is the best imaging modality to evaluate salivary gland tumors. Multiparametric MR imaging combines conventional imaging features, diffusion-weighted imaging, and perfusion imaging to help distinguish benign and low-grade neoplasms from malignant tumors; however, a biopsy is often needed to establish a definitive histopathologic diagnosis. An awareness of potential imaging pitfalls is important to prevent mistakes in salivary neoplasm imaging.

MALT Lymphoma of the Tongue in a Patient with Sjögren's Syndrome: A Case Report and Literature Review

Sjögren’s syndrome (SS) is a systemic chronic autoimmune disorder characterized by lymphocytic infiltration of the exocrine glands, as well as oral and ocular dryness. Among the late complications, malignant lymphoma is the most serious complication of SS. The risk of lymphoma in patients with SS has been estimated to be approximately 7–19 times higher than that in a generally healthy population. Although various histologic subtypes of lymphoma can occur in patients with SS, mucosa-associated lymphoid tissue (MALT) lymphoma accounts for 48–75% of malignant lymphomas that are frequently located in the parotid gland. However, MALT lymphoma affecting the tongue in patients with SS is extremely rare. Here, we share our experience with a unique case of MALT lymphoma of the tongue, originating from the minor salivary gland tissue in a patient with SS. Through this case report, we emphasize that MALT lymphoma should be considered in the differential diagnosis of a tongue mass in patients with SS.

A Primary Parotid Mucosa-Associated Lymphoid Tissue Non-Hodgkin Lymphoma in a Patient With Sjogren Syndrome

The salivary gland tumors are rare entities and the majority of these are benign. However, there are some entities such as prior neck radiation, certain infections, and systemic diseases which should raise the clinical suspicion for a malignant lesion. Patients with Sjogren syndrome are at increased risk for a salivary gland neoplasm, specifically non-Hodgkin lymphoma. While clinical findings play an important role in the initial workup, imaging plays a critical role in the diagnosis and management. This case describes a patient with Sjogren syndrome who presented with a left face mass where imaging was able to confidently diagnose her with a suspicious parotid neoplasm with lymphoma as the favored diagnosis. After histological evaluation, she was diagnosed with primary parotid mucosa-associated lymphoid tissue (MALT) non-Hodgkin lymphoma after which she went on to non-operative management.

A CT-based radiomics nomogram for differentiation of lympho-associated benign and malignant lesions of the parotid gland

OBJECTIVES

Preoperative differentiation between benign lymphoepithelial lesion (BLEL) and mucosa-associated lymphoid tissue lymphoma (MALToma) in the parotid gland is important for treatment decisions. The purpose of this study was to develop and validate a CT-based radiomics nomogram combining radiomics signature and clinical factors for the preoperative differentiation of BLEL from MALToma in the parotid gland.

METHODS

A total of 101 patients with BLEL (n = 46) or MALToma (n = 55) were divided into a training set (n = 70) and validation set (n = 31). Radiomics features were extracted from non-contrast CT images, a radiomics signature was constructed, and a radiomics score (Rad-score) was calculated. Demographics and CT findings were assessed to build a clinical factor model. A radiomics nomogram combining the Rad-score and independent clinical factors was constructed using multivariate logistic regression analysis. The performance levels of the nomogram, radiomics signature, and clinical model were evaluated and validated on the training and validation datasets, and then compared among the three models.

RESULTS

Seven features were used to build the radiomics signature. The radiomics nomogram incorporating the clinical factors and radiomics signature showed favorable predictive value for differentiating parotid BLEL from MALToma, with AUCs of 0.983 and 0.950 for the training set and validation set, respectively. Decision curve analysis showed that the nomogram outperformed the clinical factor model in terms of clinical usefulness.

CONCLUSIONS

The CT-based radiomics nomogram incorporating the Rad-score and clinical factors showed favorable predictive efficacy for differentiating BLEL from MALToma in the parotid gland, and may help in the clinical decision-making process.

KEY POINTS

• Differential diagnosis between BLEL and MALToma in parotid gland is rather difficult by conventional imaging modalities. • A radiomics nomogram integrated with the radiomics signature, demographics, and CT findings facilitates differentiation of BLEL from MALToma with improved diagnostic efficacy.

Ultrasound and Bioptic Investigation of Patients with Primary Sjögren's Syndrome

Primary Sjögren's syndrome (pSS) is a chronic and heterogeneous disorder characterized by a wide spectrum of glandular and extra-glandular features. The hallmark of pSS is considered to be the immune-mediated involvement of the exocrine glands and B-cell hyperactivation. This leads pSS patients to an increased risk of developing lymphoproliferative diseases, and persistent (>2 months) major salivary gland enlargement is a well-known clinical sign of possible involvement by B cell lymphoma. Better stratification of the patients may improve understanding of the mechanism underlying the risk of lymphoproliferative disorder. Here, we summarize the role of different imaging techniques and a bioptic approach in pSS patients, focusing mainly on the role of salivary gland ultrasonography (SGUS) and a US-guided core needle biopsy (Us-guided CNB) as diagnostic and prognostic tools in pSS patients with persistent parotid swelling.

Imaging features of parotid gland oncocytoma: a case series study

Background

Reports regarding the imaging findings of parotid gland oncocytoma are limited and prospective definitive diagnosis is difficult. This case series is aimed at furthering the knowledge of imaging for parotid gland oncocytoma.

Methods

Seven patients with pathologically confirmed parotid gland oncocytoma were identified between January, 2016 and August, 2020. They were subjected to computed tomography, magnetic resonance imaging or ultrasound. Imaging features of lesions were retrospectively analyzed and documented by a senior radiologist.

Results

Among the 7 recruited parotid gland oncocytoma patients, 4 were males and 3 were females. They were aged between 47 and 87 years with a median age of 63 years. The range of maximum diameter of the mass was about 1.6-4.5 cm, with the median size being 3.5 cm. All cases were unilateral single masses. Three patients had their parotid gland oncocytoma located in the deep lobe of the parotid gland and 4 patients had their parotid gland oncocytoma located in the superficial lobe. Most lesions exhibited a clear boundary and irregular shapes or lobulated, and contain cystic components. Local pain was the most common clinical manifestation. Most of the lesions exhibited a hypoechoic mass on ultrasound, soft tissue density on computed tomography, iso to hypointense signal on T1 weighted imaging, slightly hypersignal on T2 weighted imaging, while contrast-enhanced computed tomography, magnetic resonance imaging, and ultrasound showed avid enhancement.

Conclusions

Parotid gland oncocytomas usually exhibit a clear boundary to surrounding parotid tissue, lobulated or irregular shape and avid enhancement, sometimes accompanied with cystic components. Diagnosis of parotid gland oncocytoma should be considered when these features are encountered in clinical practice.

Current status of imaging of Sjogren's syndrome

Primary Sjögren's syndrome (pSS) is an autoimmune disease, which involves salivary glands (SG) and extra glandular organs. Today, Sjögren's patients' diagnosis is based on classification criteria taking into account five objective tests, including histology, immunology, two ophthalmological tests, and salivary flow evaluation. To date, the challenge is to find the right imaging tool for diagnosis, follow up, and prognosis of pSS. The objective of this review is to describe as to what are these imaging modalities and particularly the place and validity of salivary glands ultrasonography (SGUS) in the diagnosis and follow-up strategy of patients with suspected pSS. Moreover, new noninvasive tools are emerging, including elastography, a new ultrasonography technique that provides an estimate of tissue elasticity, MRI, MR sialography, and ¹⁸ fluorodeoxyglucose-positron emission tomography. Although new imaging opportunities are available, SGUS should be the first-line choice in pSS because of its accessibility, feasibility over time, and sensitivity to change.

Imaging in Primary Sjögren's Syndrome

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease characterized by dysfunction and lymphocytic infiltration of the salivary and lacrimal glands. Besides the characteristic sicca complaints, pSS patients can present a spectrum of signs and symptoms, which challenges the diagnostic process. Various imaging techniques can be used to assist in the diagnostic work-up and follow-up of pSS patients. Developments in imaging techniques provide new opportunities and perspectives. In this descriptive review, we discuss imaging techniques that are used in pSS with a focus on the salivary glands. The emphasis is on the contribution of these techniques to the diagnosis of pSS, their potential in assessing disease activity and disease progression in pSS, and their contribution to diagnosing and staging of pSS-associated lymphomas. Imaging findings of the salivary glands will be linked to histopathological changes in the salivary glands of pSS patients.

The clinicopathological features of parotid lymphoma

Lymphoma of the parotid gland is a rare malignant tumor, and cohort studies on the survival rates of affected patients are sparse. This study aimed to retrospectively evaluate the clinicopathological characteristics of patients diagnosed with non-Hodgkin lymphoma of the parotid gland. This study included 31 patients diagnosed with lymphoma of the parotid gland. Data on the pathological subtypes, the WHO classifications of the hematopoietic and lymphoid tissues, and the Ann Arbor staging, treatment modalities, and survival times were collected and analyzed. Among the 31 patients, there were 18 cases of extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT), 7 cases of diffuse large B-cell lymphoma (DLBCL), and 6 cases of follicular lymphoma (FL). The tumors were most-commonly located in the superficial lobe of the parotid gland (28/31), and three cases involved the deep lobe of the parotid gland (3/31). The overall median survival from the diagnosis of lymphoma was estimated to be 62 months, with 3-year and 5-year survival rates of 83.9% and 77.4%, respectively. A univariate analysis demonstrated statistically significant differences in accelerated tumor growth (P<0.001) and the presence of tumor capsules (P<0.001). A multivariate analysis demonstrated statistically significant differences in the accelerated tumor growth (P=0.029). MALT lymphoma was the most common subtype of primary parotid lymphoma. The prognosis is better than it is with other malignant parotid tumors. The presence of accelerated tumor growth was significantly correlated with overall survival time.

Extranodal Lymphomas: a pictorial review for CT and MRI classification

Extranodal lymphomas represent an extranodal location of both non-Hodgkin and Hodgkin lymphomas. This study aims to evaluate the role of CT and MRI in the assessment of relationships of extranodal lymphomas with surrounding tissues and in the characterization of the lesion. We selected and reviewed ten recent studies among the most recent ones present in literature exclusively about CT and MRI imaging of extranodal lymphomas. Contrast-enhanced computed tomography (CT) is usually the first-line imaging modality in the evaluation of extranodal lymphomas, according to Lugano classification. However, MRI has a crucial role thanks to the superior soft-tissue contrast resolution, particularly in the anatomical region as head and neck. (www.actabiomedica.it)

Relevance on the diagnosis of malignant lymphoma of the salivary gland

Malignant lymphoma originates from the lymphohematopoietic system. It can occur in any lymphoid tissue. Malignant lymphoma of the salivary gland is rare, but its incidence has increased in recent years. Its clinical- presentations are non-specific, and it is often manifested as a painless mass in a salivary gland, which can be accompanied by multiple swollen cervical lymph nodes. Confirmation of the diagnosis before an invasive procedure is difficult. Clinically, malignant lymphoma of the salivary gland tends to be misdiagnosed, leading to an inappropriate treatment plan and the ultimate delay in the optimal treatment of the disease. This article reviews the pathogenesis, clinical features, imaging findings, diagnosis, treatment and prognosis of malignant lymphoma of the salivary gland.

Linfoma no Hodgkin tipo MALT de la glándula parótida

Lymphomas of the salivary glands are a rare entity with a rare incidence. They are more commonly found on the parotid gland, followed by the submandibular and sublingual glands. The majority of parotid lymphomas are non-Hodgkin’s lymphomas and are considered to be derived from mucosal-associated lymphoid tissue (MALT). Reports of these cases are scarce and often misdiagnosed since: their manifestation is relatively benign, they have a localized behavior, a slow growth and the evolution takes several years. Key words: Type MALT lymphoma; parotid gland tumor

Comparison of Clinical Characteristics and Magnetic Resonance Imaging of Salivary Glands With Magnetic Resonance Sialography in Sjögren's Syndrome

OBJECTIVES/HYPOTHESIS

To compare the results of magnetic resonance imaging with magnetic resonance sialography (MRSIAL) and the clinical and laboratory characteristics in a well-characterized cohort of patients with primary or secondary Sjögren's syndrome (SS) meeting the American-European Consensus Group criteria.

STUDY DESIGN

Retrospective, observational, monocentric study.

METHODS

Thirty-six patients (81% female, mean age = 48 ± 35 years) with primary or secondary SS who underwent MRSIAL were included in the study.

RESULTS

MRSIAL revealed characteristic radiological signs in the parotid, sublingual, and submandibular salivary glands in 35/36 patients (97%). Patients presenting with anti-Sjögren's syndrome-related antigen A (SSA) autoantibodies showed more often fatty infiltration, a "pepper-and-salt" appearance, ductal stenosis, and/or ductal dilation of the parotid gland (88%, 88%, and 72% respectively) than patients negative for anti-SSA (12%, 4%, and 28% respectively). MRSIAL demonstrated signs characteristic of SS in all 11 patients with negative minor salivary gland biopsy. For 15 patients undergoing ultrasound examination only, 11 (73%) had SS findings, but all 15 had SS findings on MRSIAL. Two cases of parotid lymphoma were detected by MRSIAL (6%).

CONCLUSIONS

MRSIAL is a reliable technique to detect glandular anomalies in patients with SS, and seems to provide a valuable aid in the diagnosis of SS.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E83-E89, 2021.

Peripheral T Cell Lymphoma of Parotid Gland: A Diagnostic Challenge

Peripheral T-cell lymphoma of salivary gland is a rare clinical entity most commonly involving the parotid gland and mimics a salivary gland carcinoma. It has an aggressive clinical course with poor prognosis. Majority of the cases are diagnosed after surgical excision whereas the principal treatment is non-surgical (chemotherapy). Core biopsy is an excellent method of identifying these indeterminate lesions pre-operatively which would avoid unnecessary surgical intervention. We present a case report with diagnostic challenge in identifying peripheral T cell lymphoma of salivary gland with the review of literature.

Immunohistochemical Reappraisal Regarding the Frequency of Primary Salivary Gland Follicular Lymphoma

Although it has been described that extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT lymphomas) are the most common type among primary salivary gland lymphomas (SGLs), some studies revealed that the frequency of follicular lymphomas (FLs) was as high as that of MALT lymphomas. However, it has been reported that many of these FLs may have developed in lymph nodes attached to the capsule of the glands or intraglandular lymph nodes. Clinical, histological, immunohistochemical, and cytogenetic features of 11 SGL cases, which were extracted from our surgical pathology file consisting of consecutive pathology cases, were reevaluated to further characterize whether they were actually primary SGLs. There were 3 (27%) cases of FLs, 5 (46%) cases of MALT lymphomas, and 3 (27%) cases of diffuse large B-cell lymphomas. Although all of our FL cases fulfilled the criteria of primary SGL, tumors of several FL cases were surrounded by podoplanin (by D2-40)-positive elongated vessels or linear structures indicative of nodal subcapsular sinuses (open or remnant). This finding would support the aforementioned possibility, and podoplanin staining is necessary before concluding that a FL is a primary SGL.

Lymphoepithelial carcinoma of salivary glands: CT and MR imaging findings

OBJECTIVES

To depict the CT and MRI characteristics of salivary gland lymphoepithelial carcinoma (LEC) and provide more diagnostic information for this malignancy.

METHODS

103 salivary gland LEC subjects were retrospectively reviewed. The subjects include 35 males with a mean age of 40.8 years and 68 females with a mean age of 49.4 years. Of the 103 subjects, 86 had carcinomas in the parotid gland, 5 in the submandibular gland, 1 in the sublingual gland, 3 in the cheek and 8 in the palate. All subjects underwent routine CT and MRI (plain and contrast-enhanced scans) prior to surgical treatment and histopathological examination.

RESULTS

Based on the pathological outcomes, all the salivary gland LECs were classified into two types from CT and MRI scans: solitary LEC (56 cases, 54.4%) and multiple LEC (47 cases, 45.6%). The latter included solitary salivary gland LEC with extraglandular lymph-node metastases (12 cases), parotid gland LEC with ipsilateral intraglandular lymph-node metastases (11 cases), parotid gland LEC with ipsilateral intra- and extraglandular lymph-node metastases (23 cases) and bilateral parotid gland LEC (1 case). The salivary gland LEC was depicted on CT and MRI scans as a lobular mass in 64 of 104 (61.5%), homogeneous mass in 65 of 104 (62.5%) or enhanced neoplasm in 94 of 104 (90.4%).

CONCLUSIONS

Salivary gland LEC has a predilection for females in the fourth to fifth decade of life and the parotid gland. CT and MRI findings between solitary and multiple salivary LECs vary. A majority of multiple parotid gland LECs are characterized by metastasis of ipsilateral intraglandular lymph nodes, which may accompany with or without extraglandular lymph-node metastases.

Multimodality Imaging Spectrum of the Extranodal Lymphomas in the Head and Neck-A Pictorial Review

Lymphoma is the second most common malignant neoplasm of the head and neck region, involving the nodal and/or extranodal sites or both in a variable fashion. Lymphoma may mimic a variety of tumors in this region depending on the subsite involved. The usual presentation of lymphomatous disease is presence of multiple enlarged, often conglomerate, lymph nodes without significant necrosis. Extranodal lymphomas demonstrate more complex radiologic features, but careful evaluation can identify distinct imaging patterns to suggest extranodal lymphomatous disease from other more common lesions. Knowledge of these imaging features can help raise suspicion for lymphoma as a differential consideration. This can be of critical importance since further work-up and management can be vastly different between lymphomatous disease and other disease entities. The authors present a pictorial review of the spectrum of imaging findings in extranodal head and neck lymphomas.

Intravoxel incoherent motion MR imaging measurements of the bilateral parotid glands at 3.0-T MR: effect of age, gender and laterality in healthy adults

OBJECTIVE

To investigate the effect of age, gender and laterality on the intravoxel incoherent motion (IVIM) MR imaging measurements of parotid glands in healthy participants at 3.0-T MRI.

METHODS

A total of 108 healthy participants were prospectively recruited. IVIM MRI scan was performed using a 3.0-T MR scanner, and corresponding parameters (perfusion fraction, f; pseudodiffusion coefficient, D*; tissue diffusivity, D) were derived from biexponential fitting of IVIM data. Pearson correlation analysis was performed to determine the association between the IVIM MRI parameters and age. The parameter difference between male and female participants or between left and right parotid glands was compared using unpaired or paired t test, respectively.

RESULTS

Excellent interreader and intrareader agreements on the measurements of IVIM MRI parameters were achieved. Both D and f values correlated inversely with the age in both left and right parotid glands (p < 0.05) while D* value did not (p > 0.05). Male participants had higher IVIM MRI parameters than the female participants in both left and right glands (p < 0.05). No significant differences were found in the IVIM MRI parameters between left and right glands in both male and female participants (p > 0.05).

CONCLUSION

The IVIM MRI parameters are age and gender dependent, but not laterality dependent. Age- and gender-related effect should be taken into consideration in future IVIM MRI studies for parotid glands.

ADVANCES IN KNOWLEDGE

(1) Both D and f values correlated inversely with the age in healthy parotid glands, while D* value did not. (2) The parotid glands of males showed higher IVIM MRI parameters than that of females. (3) There were no significant differences on the IVIM MRI parameters between the left and right glands. (4) Age- and gender-related effect should be taken into consideration in future IVIM MRI studies for parotid glands.