Value of positron emission tomography in staging ocular adnexal lymphomas and evaluating their response to therapy

Is it Worthwhile to Undergo the Extended Stage Assessment in Orbital and Ocular Adnexal MALT Lymphoma with Symptoms Limited to the Ocular Adnexa?

Compared to ocular adnexal lymphoma of mucosa-associated lymphoid tissue-type (OAML) patients with symptoms related invasion beyond the ocular adnexa, the different approaches to staging assessment may be required in OAML patients with symptoms limited to the ocular adnexa. Seventy-six patients to be diagnosed with OAML and performed bone marrow biopsy and imaging study at Yeungnam University Hospital in 1995-2014 were enrolled. Patients with symptoms limited to the ocular adnexa were included. Computed tomography, magnetic resonance imaging, positron emission tomography (PET), and bone marrow biopsies were performed for diagnosis, NM staging and follow up evaluation. Most patients were treated with external beam irradiation (median dose, 30 Gray (Gy)). The relapse-free survival (RFS) was analyzed according to the tumor laterality and TNM stage. The median follow-up period was 72 months. The 5-year RFS and overall survival rates were 82.1% and 95.6% respectively. Of all 76 patients, lymph node and bone marrow involvement was identified in 1 patient, respectively. Among the 3 patients with T4 stage as tumor invasion beyond ocular adnexa, bone marrow involvement was confirmed in a patient with left cheek invasion. Only 11 of the 43 patients who underwent PET showed positive uptakes in orbital lesion. The patients with advanced stage were alive without recurrences. Bone marrow examination is useful in OAML patients with T4 for extended stage assessment. The AJCC TNM staging system was not significantly predictive factor for relapse, but may contribute to clarifying the patient group that needs bone marrow study.

Ocular adnexal lymphoma: A single-institution retrospective study

PURPOSE:

To characterize demographic, clinical, and histopathologic features of ocular adnexal lymphoma (OAL) at a single institution.

METHODS:

Retrospective review of all patients with pathologic diagnosis of OAL between 2015 and 2020.

RESULTS:

There were 133 patients with OAL, with a median age of 65 years (range 23–97) and a slight female predominance (male: female = 1:1.46), (n = 79, 59%). The majority of tumors were non-Hodgkin B-cell lymphomas (n = 131, 99%), most frequently Extranodal Marginal Zone B-Cell Lymphoma (EMZL, n = 93, 70%), followed by follicular lymphoma (n = 21, 16%), chronic lymphocytic leukemia/small lymphocytic lymphoma (n = 7, 5%), diffuse large B-cell lymphoma (n = 5, 4%), and mantle cell lymphoma (n = 5, 4%). The most frequently involved sites included the orbit (n = 85, 64%) and conjunctiva (n = 43, 32%). Information was available on oncologic staging in 78 (59%), treatment in 82 (62%), and follow-up in 75 (56%) patients. By the Ann-Arbor classification system, patients were classified as IE (54/78, 69%), IIE (9/78, 12%), IIIE (6/78, 8%), and IVE (9/78, 12%). The most common treatments included external beam radiotherapy (standard and ultra-low-dose) (48/82, 59%), biologics (22/82, 27%), and surgical excision with cryotherapy (14/82, 17%) (some patients had >1 therapy). Median follow-up time was 24 months (range 0–221 months). Recurrence was observed in 13% (10/75) with a median time to recurrence of 60 months (95% confidence interval 47–73 months). Excision with cryotherapy as a sole treatment modality was associated with earlier recurrence (P = 0.003).

CONCLUSION:

In this largest single-center study of OAL, we found that most OAL were Ann-Arbor Stage IE EMZL, occurring in older patients with a female predominance. Early recurrence was noted in tumors treated with excision and cryotherapy alone.

PET/CT and PET/MRI in ophthalmic oncology (Review)

Orbital and ocular anatomy is quite complex, consisting of several tissues, which can give rise to both benign and malignant tumors, while several primary neoplasms can metastasize to the orbital and ocular space. Early detection, accurate staging and re-staging, efficient monitoring of treatment response, non-invasive differentiation between benign and malignant lesions, and accurate planning of external radiation treatment, are of utmost importance for the optimal and individualized management of ophthalmic oncology patients. Addressing these challenges requires the employment of several diagnostic imaging techniques, such as high-definition digital fundus photography, ultrasound imaging, optical coherence tomography, optical coherence tomography (OCT)-angiography, computed tomography (CT) and magnetic resonance imaging (MRI). In recent years, technological advances have enabled the development of hybrid positron emission tomography (PET)/CT and PET/MRI systems, setting new standards in cancer diagnosis and treatment. The capability of simultaneously targeting several cancer-related biochemical procedures using positron emitting-radiopharmaceuticals, while morphologically characterizing lesions by CT or MRI, together with the intrinsic quantitative capabilities of PET-imaging, provide incremental diagnostic information, enabling accurate, highly efficient and personalized treatment strategies. Aim of the current review is to discuss the current applications of hybrid PET/CT and PET/MRI imaging in the management of patients presenting with the most commonly encountered orbital and ocular tumors.

Role of F-18 FDG PET/CT in non-conjunctival origin ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphomas

Background

Despite the widespread use of F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in the diagnosis and response assessment of patients with lymphoma, few studies have assessed its value in ocular adnexal lymphomas. The purpose of this study was to evaluate the role of FDG PET/CT in staging of non-conjunctival origin ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphomas (OAML). In addition, the diagnostic sensitivity of FDG PET/CT was compared with magnetic resonance imaging (MRI). FDG PET/CT of 123 consecutive patients with pathologically proven OAML between January 2009 and February 2016 were retrospectively reviewed. The patients with MALT lymphoma originating from conjunctiva were excluded. A total 50 patients with non-conjunctival origin OAML were assessed. Maximum standardized uptake value (SUVmax) and additional PET parameters were measured for all lesions. Sensitivity for primary tumor detection was compared with MRI.

Results

Ten patients had bilateral OAML and total 60 OAML lesions were analyzed. MRI was missing in one patient. The tumor locations were as follows: eyelid, 9; lacrimal gland, 18; orbit, 33. Fifty lesions (83.3%) were FDG-avid tumors with mean ± SD SUVmax 4.8 ± 2.4 (range 2.0~11.1). The mean SUVmax according to tumor location were as follows: eyelid, 3.7 ± 1.1 (2.8~5.3); lacrimal gland, 3.6 ± 1.4 (2.1~6.4); orbit, 5.7 ± 2.6 (2.0~11.1). Mean SUVmax among the 3 locations were statistically different (P = 0.010). The sensitivity was calculated as 83.1% (49/59) for FDG PET/CT and 89.8% (53/59) for MRI, which were statistically comparable (P = 0.219 by McNemar’s test). Seven of 50 patients (14%) were upstaged by detection of extraocular lesions by FDG PET/CT (1 kidney and lung, 1 tonsil, 4 cervical LNs, 1 sacral foramen).

Conclusion

83.3% of the non-conjunctival origin OAML were FDG-avid tumors, with FDG PET/CT showing comparable sensitivity to that of MRI. FDG PET/CT detected unsuspected extraocular lymphoma involvement in 14% of the patients. FDG PET/CT performed for staging of non-conjunctival origin OAML may thus guide therapeutic management.

Orbital lymphoma

Orbital lymphomas constitute 50-60% of ocular adnexal lymphomas. A total of 2211 cases of orbital lymphoma with a known subtype have been reported in the last 24 years (1994-2017). The vast majority of orbital lymphomas are of B-cell origin (97%), of which extranodal marginal zone B-cell lymphoma (EMZL) (59%) is the most common subtype, followed by diffuse large B-cell lymphoma (23%), follicular lymphoma (9%), and mantle cell lymphoma (5%). Orbital lymphoma is primarily a disease of the elderly. Gender distribution varies according to lymphoma subtype. However, extranodal marginal zone B-cell lymphoma (53%) and follicular lymphoma (75%) show a female predominance, whereas diffuse large B-cell lymphoma shows an even gender distribution. Mantle cell lymphoma has a striking male predominance of 80%. The histopathological subtype and the clinical stage of the disease are the best indicators of prognosis and patient outcome. Low-grade lymphomas such as extranodal marginal zone B-cell lymphoma and FL have a good prognosis, whereas high-grade lymphomas (diffuse large B-cell lymphoma and mantle cell lymphoma) are associated with a poor prognosis. When managing solitary low-grade lymphomas, radiotherapy is the treatment of choice. Chemotherapy, with or without radiotherapy, should be chosen for disseminated and high-grade lymphomas.

Comparison of Selection and Long-term Clinical Outcomes Between Chemotherapy and Radiotherapy as Primary Therapeutic Modality for Ocular Adnexal MALT Lymphoma

BACKGROUND

The choice of a primary treatment for ocular adnexal mucosa-associated lymphoid tissue lymphoma (OAML) depends on the extent of tumor spread. However, radiotherapy is commonly used as a first-line therapy despite ophthalmic complications, because most OAMLs are in a limited stage of progression. However, the initial therapeutic modality, including chemotherapy and treatment of the advanced stage, has not been fully established for OAML. Therefore, we evaluated the optimal therapeutic options and survival outcome-related parameters for patients with primary OAML.

METHODS

We evaluated 208 consecutive patients with primary OAML who were diagnosed at the Catholic University Lymphoma Group between January 2004 and April 2015.

FINDINGS

During a median follow-up of 70.0 months (range, 3.2-182.0 months) in 208 patients with primary OAML, most patients were female and the median age was 46 years old. Overall survival (OS) and progression-free survival (PFS) at 13 years were excellent (92.7% and 69.7%, respectively). Of the 117 patients who received the first-line radiotherapy, 92% achieved complete remission (CR), usually by being treated with less than 30 Gy. Radiation-related ophthalmic complications including dry eye syndrome (59%) and cataract (22%) caused a decline in the quality of life (QoL). Chemotherapy alone was used to treat 86 OAML patients, with 84.9% achieving CR and 12.8% achieving partial remission with tolerable toxicities. There were no differences in survival outcomes between patients treated with radiotherapy versus those treated with rituximab-containing chemotherapy, although the latter group had more advanced stages of OAML (OS, p = 0.057; PFS, p = 0.075).

INTERPRETATION

OAML patients were predominantly female and relatively young, and radiotherapy as a primary therapeutic option was more likely to lead to radiation-related complications, resulting in lower QoL. On the other hand, frontline chemotherapy showed consistent therapeutic outcomes with tolerable toxicities compared to radiotherapy, and there were no long-term or delayed adverse events. Therefore, when considering therapeutic efficacy and therapy-related QoL, chemotherapy is recommended for younger patients, and radiotherapy is recommended for older and chemotherapy-ineligible patients.

FUNDING

A National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIP) (No. NRF-2016R1A2B4007282).

Usefulness of 18F-FDG PET/CT for evaluating response of ocular adnexal lymphoma to treatment

The purpose of this study was to investigate the efficacy of F-fluoro-deoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for evaluating the ocular adnexal lymphoma treatment responses.We retrospectively reviewed data for 9 histologically confirmed cases of malignant lymphoma. All patients had at least one ocular adnexal tumor site and underwent FDG PET/CT before and after treatment. Patients' histological disease subtypes included diffuse large B-cell lymphoma (n = 3), mucosa-associated lymphoid tissue lymphoma (n = 2), follicular lymphoma (n = 1), NK/T-cell lymphoma (n = 1), lymphoplasmacytic lymphoma (n = 1), and Hodgkin lymphoma (n = 1). The highest FDG uptake by the ocular adnexal lesions was calculated as the maximum standardized uptake value (SUVmax). FDG uptake at ocular adnexal sites and sites of systemic disease after treatment were also assessed using the 5-point Deauville scale.In 1 of the 9 patients, a conjunctival lesion could not be detected by either pre- or posttreatment PET/CT. For 8 of the 9 patients, the SUVmax value at the ocular adnexal site significantly decreased after treatment (7.1 ± 5.1 vs 1.6 ± 0.58; P = .0196). For 7 of the 9 patients, the first posttreatment FDG uptake at the ocular adnexal site was considered a complete metabolic response, and these patients showed an improved clinical ophthalmic presentation with no relapse at ocular adnexal sites during follow-up.FDG PET/CT is useful for evaluation of the response of ocular adnexal lymphoma to treatment, although its usefulness may depend on the histological subtype and site of the lesion.

Ocular adnexal marginal zone lymphoma of mucosa-associated lymphoid tissue

Ocular adnexal lymphomas are a group of heterogeneous neoplasms representing approximately 1-2% of non-Hodgkin lymphomas and 8% of extranodal lymphomas. The incidence of primary ocular adnexal lymphoid tumors has raised over the last decades, and this could be probably attributed to the more sophisticated diagnostic techniques. Due to the wide spectrum of clinical manifestations, ocular tissue biopsy is important in order to set a precise diagnosis based on histological, immunophenotypical and, in some cases, molecular findings. The most common subtype, which may account for up to 80% of primary ocular adnexal lymphomas, is extranodal marginal zone lymphoma (EMZL) of mucosa-associated lymphoid tissue. This lymphoma is usually asymptomatic in the early phase of the disease causing a delay in the final diagnosis and prompt therapy. The pathogenesis of a proportion of these tumors has been linked to chronic inflammatory stimulation from specific infectious factors (e.g., Chlamydia psittaci) or to autoimmunity. The further improvement in diagnostic methods and the further understanding of the pathogenesis of ocular adnexal EMZL may contribute to the establishment of a more successful multidisciplinary therapeutic planning.

Extranodal Marginal Zone B-cell Lymphoma of the Ocular Adnexa

BACKGROUND

Low-grade B-cell lymphomas located around the eye present unique challenges in diagnosis and treatment. Extranodal marginal zone B-cell lymphoma is the most common lymphoma of the ocular adnexa (conjunctiva, orbit, lacrimal gland, and eyelid).

METHODS

A systematic search of the relevant literature was performed. Material pertinent to the diagnosis, prognosis, pathogenesis, and treatment of extranodal marginal zone B-cell lymphoma of the ocular adnexa was identified, reviewed, and analyzed, focusing on management strategies for primary localized disease.

RESULTS

The primary cause of extranodal marginal zone B-cell lymphoma of the ocular adnexa remains elusive, although an infectious agent is suspected. Radiotherapy is the most common initial treatment for localized disease. Initial treatment with chemotherapy, immunotherapy, and antibiotics has shown promising results, but the number of series is limited and controlled trials do not exist.

CONCLUSIONS

Although the long-term outcome of localized extranodal marginal zone B-cell lymphoma of the ocular adnexa is good, optimal treatment remains a goal. The variation in rates of local and systemic relapse among treated stage 1E tumors suggests that critical factors affecting outcomes are not fully understood. Radiotherapy is the standard of care; at this time, the evidence is insufficient to recommend chemotherapy, immunotherapy, or antibiotics for initial treatment of extranodal marginal zone B-cell lymphoma localized to the ocular adnexa. Well-controlled comparative studies are needed.

Orbital tumours and tumour-like lesions: exploring the armamentarium of multiparametric imaging

Although the orbit is a small anatomical space, the wide range of structures present within it are often the site of origin of various tumours and tumour-like conditions, both in adults and children. Cross-sectional imaging is mandatory for the detection, characterization, and mapping of these lesions. This review focuses on multiparametric imaging of orbital tumours. Each tumour is reviewed in relation to its clinical presentation, compartmental location, imaging characteristics, and its histological features. We herein describe orbital tumours as lesions of the globe (retinoblastoma, uveal melanoma), optic nerve sheath complex (meningioma, optic nerve glioma), conal-intraconal compartment (hemangioma), extraconal compartment (dermoid/epidermoid, lacrimal gland tumours, lymphoma, rhabdomysarcoma), and bone and sinus compartment (fibrous dysplasia). Lesions without any typical compartmental localization and those with multi-compartment involvement (veno-lymphatic malformation, plexiform neurofibroma, idiopathic orbital pseudotumour, IgG4 related disease, metastases) are also reviewed. We discuss the role of advanced imaging techniques, such as MR diffusion-weighted imaging (DWI), diffusion tensor imaging, fluoro-2-deoxy-D-glucose positron emission tomography CT (FDG-PET CT), and positron emission tomography MRI (MRI PET) as problem-solving tools in the evaluation of those orbital masses that present with non-specific morphologic imaging findings. Main messages/Teaching points • A compartment-based approach is essential for the diagnosis of orbital tumours. • CT and MRI play a key role in the work-up of orbital tumours. • DWI, PET CT, and MRI PET are complementary tools to solve diagnostic dilemmas. • Awareness of salient imaging pearls and diagnostic pitfalls avoids interpretation errors.

Outcomes of primary lymphoma of the ocular adnexa (orbital lymphoma) treated with radiotherapy

AIMS

Low-grade ocular adnexal lymphoma is a rare disease and often treated with local radiotherapy to varying doses. Most previously reported studies have a very heterogeneous patient population and treatments. We report the outcomes from a 10 year cohort of patients at our institution treated with primary radiation therapy.

MATERIALS AND METHODS

We analysed a retrospective case series of patients with stage IE low-grade ocular adnexal lymphoma including a review of case notes, histological reports and radiotherapy charts. We assessed local and distant tumour control and relapse rates in addition to toxicity. Disease-free survival was estimated using the Kaplan-Meier method.

RESULTS

In total, 81 patients and 85 orbits were treated with primary radiotherapy to a median dose of 30 Gy in 15 fractions over 3 weeks. Seventy-nine per cent were treated with standard MV external beam radiotherapy to the whole orbit and 21% with a lens-sparing technique. The median follow-up was 4.4 years (range 0.2-10.4). Local control rates were 100%, with 5% of patients experiencing disease relapse elsewhere. No patients died from lymphoma. Cumulative acute toxicity rates were 51% (mainly erythema and conjunctivitis) and late toxicity rates were 8% (mainly cataract). The lens-sparing technique was associated with a significant reduction in cataract rate (P = 0.013) and an increase in acute toxicity (P < 0.001).

CONCLUSIONS

This study has shown excellent local control rates and acceptable toxicity from the treatment of stage IE low-grade ocular adnexal lymphoma with localised radiotherapy to a median dose of 30 Gy in 15 fractions over 3 weeks.

Conjunctival MALT lymphoma: utility of FDG PET/CT for diagnosis, staging, and evaluation of treatment response

A 67-year-old woman was referred for staging of a mucosa-associated lymphoid tumor lymphoma involving the left conjunctiva. CT scan had shown paravertebral and pelvic masses, and a breast nodule. FDG PET/CT demonstrated moderately increased uptake in the left ocular conjunctiva and confirmed the paravertebral and pelvic masses and the breast nodule. Moreover, abnormal FDG uptake was shown in 2 breast nodules, the flank, the gluteus maximus, and the gastric cardia. The patient received 6 cycles of rituximab-bendamustine chemotherapy with a complete clinical and metabolic response at the 6-month follow-up PET/CT and remained relapse-free without visual acuity problem after a 36-month follow-up.

Value of positron emission tomography/computed tomography in diagnosis and staging of primary ocular and orbital tumors

Accurate and reliable staging methods are crucial for optimal care of patients with ocular and orbital malignancies. Positron emission tomography/computed tomography (PET/CT) has recently emerged as a staging tool in the field of ophthalmic oncology. For detecting primary ocular or orbital lesions, PET/CT does not seem to provide an advantage over clinical ophthalmologic examination or conventional imaging studies such as CT or magnetic resonance imaging of the orbit. However, PET/CT may detect distant metastatic lesions that conventional imaging studies miss. For orbital and ocular adnexal lymphoma, use of PET/CT has been proven to be feasible and is now accepted both as a standard part of the initial staging work-up and for the assessment of response to therapy. For other ophthalmic tumors, PET/CT seems most appropriate for advanced metastatic tumors of the orbit, eyelid, and eye, for which the detection of distant metastasis with 1 comprehensive study may be preferable to performing multiple CT scans with contrast.

Ocular adnexal lymphomas: a review

Ocular adnexal lymphomas comprise 1% to 2% of all non-Hodgkin lymphomas and about 8% of extranodal lymphomas. They are a heterogeneous group of malignancies, the majority of which are primary extranodal lymphoma with most (up to 80%) of the marginal zone of mucosa associated lymphoid tissue type (MALT lymphoma). This review will encompass the incidence, histology, immunophenotyping, recent advances in molecular and cytogenetics, clinical features including outcome, and prognostic factors. The association with Chlamydia psittaci and the very recently recognized occurrence in the context of IgG4-related sclerosing disease will be discussed. Finally, traditional (surgery, radiotherapy, chemotherapy) and newer forms of therapy (immunotherapy and radioimmunotherapy) will be reviewed.

FDG PET-CT in the management of primary breast lymphoma

OBJECTIVE

Primary breast lymphoma (PBL) is a rare disease and its management differs from other breast cancers. The purpose of this study is to evaluate the role of FDG PET-CT in the management of PBL. We carried out 16 PET-CT scans and reviewed the literature.

MATERIALS AND METHODS

A total of 16 FDG PET-CT scans were done in 8 female patients with PBL with a median age of 49 years (range: 27-68). Of the 16 PET-CT scans, 1 scan was done for primary diagnosis and staging (1 patient), 2 for staging (2 patients), 7 for evaluation of treatment response (6 patients), and 6 for detecting recurrence (4 patients). PET-CT image interpretation and analysis were performed qualitatively (visually) and semiquantitatively using standardized uptake value (SUV). Absence of uptake in the postchemotherapy follow-up PET-CT scan was considered as a complete response, and a fall of more than 50% of baseline SUV was considered as a significant response.

RESULTS

One patient was successfully diagnosed to have PBL and staged using PET-CT. Two patients were correctly staged with the help of FDG PET-CT. Complete response was noted in all 6 patients (3 had a positive baseline scan and showed complete resolution of FDG uptake, the other 3 who did not have baseline PET-CT and lesions were detected on CT, and also showed complete resolution). Of the 4 patients evaluated for recurrence, 1 patient was positive and 3 patients were negative for recurrence in follow-up PET-CT scans done after 18, 22, and 24 months, respectively.

CONCLUSION

FDG PET-CT has a definitive role in every step of management (diagnosis, staging, treatment response evaluation, and detection of recurrence) in patients with primary breast lymphoma.

Estimation of yttrium-90 Zevalin tumor-absorbed dose in ocular adnexal lymphoma using quantitative indium-111 Zevalin radionuclide imaging

OBJECTIVE

The purpose of this investigation was to estimate radiation-absorbed dose in orbital tumors from yttrium-90 ibritumomab tiuxetan (Zevalin) radioimmunotherapy of ocular adnexal lymphoma.

METHODS

Three patients participating in a prospective research protocol involving treatment of ocular adnexal lymphoma with yttrium-90 Zevalin consented to quantitative radionuclide imaging to estimate tumor radiation-absorbed doses. Each patient received 185 MBq of indium-111 Zevalin, followed by serial planar whole-body scanning, to derive an activity versus time curve for the tumor. Single photon emission computed tomography (SPECT) and computed tomography (CT) imaging, including a calibration source, were performed at 24 h on a SPECT/CT scanner, to obtain a SPECT estimate of the radioactivity (in megabequerels) in the tumor and correct the planar curve, as well as estimate the tumor mass (M) from CT. The curve was then converted to that for yttrium-90 at the prescribed activity, and absorbed dose estimated from the area under the curve multiplied by the Medical Internal Radiation Dose S value (Gy per MBq-h) for a sphere of mass M.

RESULTS

A right orbital tumor in one patient was visualized in both the planar and SPECT/CT images, with an estimated absorbed dose of 3.57 Gy. Tumor uptake in the other two patients was not visualized.

CONCLUSION

The radiation dose to the orbit and ocular structures during radioimmunotherapy of ocular adnexal lymphoma is well below the threshold for significant radiation-induced ocular toxicity and about 10 times lower than that delivered during external beam radiotherapy.

Extranodal marginal zone lymphoma of the ocular adnexa

Lymphomas of the ocular adnexa are a heterogeneous group of malignancies, composing approximately 1% to 2% of non-Hodgkin lymphomas (NHLs) and 8% of extranodal lymphomas. The most common subtype, accounting for up to 80% of cases of primary ocular adnexal lymphoma, is marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) type. In the recent past, there have been significant advances in our understanding of the clinical characteristics, morphology and phenotype, etiology, pathogenesis, diagnosis, natural history, treatment approaches, outcome, and prognostic factors of this disease entity. Novel immunologic and molecular techniques have aided in the distinction between MALT lymphoma and other lymphoproliferative disorders and led to the identification of tissue markers of prognostic significance. Modern imaging modalities provide invaluable tools for accurate staging and treatment planning. Besides radiotherapy and chemotherapy, a variety of new treatment options have emerged in the management of patients with ocular adnexal MALT lymphoma, especially monoclonal antibody therapy and antibiotic therapy against Chlamydia psittaci, which has been associated with the pathogenesis of ocular adnexal lymphomas in some parts of the world. In this review, we present a state-of-the-art summary of ocular adnexal MALT lymphomas.

PET Imaging of Skull Base Neoplasms

The utility of 18-F-fluorodeoxyglucose-positron emission tomography (PET) and PET/CT for the evaluation of skull base tumors is incompletely investigated, as a limited number of studies specifically focus on this region with regard to PET imaging. Several patterns can be ascertained, however, by synthesizing the data from various published reports and cases of primary skull base malignancies, as well as head and neck malignancies that extend secondarily to the skull base, including nasopharyngeal carcinoma, nasal cavity and paranasal sinus tumors, parotid cancers, and orbital tumors.