British Journal of Radiology 74 (2001),226-229 © 2001 The British Institute of Radiology
MRI of primary non-Hodgkin's lymphoma of the palatine tonsil
A D King, FRCR1,
K I K Lei, MRCP2 and
A T Ahuja, FRCR1
1 Departments of Diagnostic Radiology and Organ Imaging
2 Clinical Oncology, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR, China
 |
Abstract
|
|---|
Non-Hodgkin's lymphoma (NHL) arising primarily in the palatine tonsil is uncommon. The aims of the study were to describe the appearances on MRI and to identify the features that help to distinguish NHL from other tonsillar tumours. The clinical records and MR images of eight patients with primary NHL of the palatine tonsil were reviewed. Patients had a short duration of symptoms (mean 1 month). Systemic symptoms (fever, weight loss or night sweats) occurred in two patients. Tumours were round or lobulated and ranged in size from 30 mm to 70 mm. The signal intensity on T2 weighted, T1 weighted and T1 weighted contrast enhanced images was homogeneous and similar to that of normal tonsil in six patients. Two large tumours were mildly heterogeneous and one of these showed small foci of necrosis. NHL of the tonsil displaced rather than invaded local structures in seven patients and locally invaded the soft palate in only one patient. Lymphadenopathy was present in five patients and the nodes were of similar signal intensity to the primary tumour. There was involvement of the ipsilateral upper internal jugular chain in all cases of lymphadenopathy. The posterior triangle was involved in two patients, the periparotid node in one patient and the retro-oropharyngeal region in one patient. The presence of a large tumour without deep invasion together with homogeneous non-necrotic nodes suggests the diagnosis of NHL. As NHL frequently has similar signal intensity to normal tonsil, MRI may not be able to detect lymphomatous involvement in the non-enlarged tonsil.
|
Introduction
|
|---|
Lymphoma is the second most common malignant tumour of the head and neck. 90% of lymphomas in this region arise in nodes [1, 2], the majority being due to Hodgkin's disease. In contrast, non-Hodgkin's lymphoma (NHL) accounts for only 5% of head and neck tumours and is frequently found in the extranodal lymphatic sites of Waldeyer's ring or in extranodal extralymphatic sites such as the sinuses, salivary glands, thyroid and orbits. The tonsil is one of the most frequent sites of involvement of NHL in the head and neck [3, 4]. Lymphomatous involvement of the tonsil may be diagnosed during clinical or radiological staging for NHL elsewhere, or it may be the primary site of tumour. Primary NHL of the tonsil presents with a sore throat or a lump in the throat. Clinical examination shows a tumour. Imaging may be performed for a suspected squamous cell carcinoma, which is the most common malignant tumour at this site. CT features of NHL of the palatine tonsil have been described [5] but not the MRI features. The aims of the study were to review the appearance of primary tonsillar NHL on MRI and to determine whether there are features that distinguish it from other tonsillar tumours.
|
Materials and methods
|
|---|
14 Chinese patients with NHL involving the palatine tonsil were imaged between 1998 and 2000. Three patients were excluded because the tonsillar lymphoma was diagnosed during clinical staging for NHL elsewhere in the body, two patients with multifocal NHL in Waldeyer's ring and one with mediastinal lymphoma. The remaining 11 patients were considered to have primary lymphoma based on symptoms, clinical examination and investigation at the time of presentation [6]. 3 of these 11 patients underwent tonsillectomy before imaging. The MR images of the remaining eight patients (four men, four women; age range 31–84 years, mean 57 years) were reviewed retrospectively. Images were obtained on a 1.5 T MR unit (Philips Gyroscan, Eindhoven, The Netherlands) using a head coil (30 cm diameter). All patients underwent a T1 weighted spin echo sequence (TR/TE 500/20; field of view 22 cm; slice thickness 4 mm, with no interslice gap; matrix size 256x202 or 512x408) before and after contrast enhancement, and a T2 weighted turbo spin echo sequence (TR/TE 2500/100; echo train length 14; field of view 22 cm; slice thickness 4 mm, with no interslice gap; matrix size 256x202) and/or a fat suppressed T2 weighted sequence (TR/TE 2500/100 msec; echo train length 15; field of view 22 cm, slice thickness 4 mm, with no interslice gap; matrix size 256x202). Images were obtained in at least two planes.
The clinical records were reviewed for clinical presentation and staging. MRI examinations were assessed for tumour signal characteristics, contour, invasion of adjacent structures and cervical nodes.
|
Results
|
|---|
Presenting symptoms
Patients presented with sore throat (n=6), tonsillar swelling (n=4), neck mass (n=3), dysphagia (n=2) and systemic symptoms (n=2). The duration of symptoms ranged from 1 week to 2 months (mean 1 month).
MR appearance of tonsillar lymphoma
Tonsillar lymphoma involved the right side in seven cases and the left side in one case. Tumour size ranged from 30 mm to 70 mm (mean 50 mm). All tumours were well defined, with a round (n=3) or lobulated (n=5) contour.
On T2 weighted images the signal intensity was mildly increased in all cases, being homogeneous in six cases and heterogeneous in two cases. On T1 weighted images the signal intensity was intermediate and homogeneous in all cases. All tumours demonstrated mild enhancement following iv gadolinium, being homogeneous in seven cases and heterogenous with small necrotic foci in one case.
Tumour invasion into the soft palate occurred in one case. In the remaining seven patients there was no invasion outside the tonsil into adjacent soft tissues.
Cervical lymphadenopathy
Cervical lymphadenopathy was present in five patients. Lymphadenopathy was unilateral in four cases and bilateral in one case. In all patients with lymphadenopathy there was involvement of the high internal jugular chain on the ipsilateral side to the tonsillar lymphoma. In addition there was involvement of the posterior triangle (n=2), retropharyngeal region (n=1) and parotid region (n=1).
The signal intensity of the nodes was similar to that of the primary tumour, being of homogeneous signal intensity in four cases and heterogeneous with small necrotic foci in one case.
|
Discussion
|
|---|
The majority of malignant tumours of the palatine tonsil are squamous cell carcinomas (SCCs). Non-Hodgkin's disease is the second most common tumour of the tonsil, accounting for 5–14% of tumours at this site [7, 8]. Lymphoepithelioma, plasmacytoma, adenocarcinoma, salivary gland tumours, melanoma, Hodgkin's disease, sarcoma and metastatic tumours account for the remaining few per cent. Both SCC and NHL have a male predominance and tend to affect the older age group. NHL of the tonsil has a mean age of onset of 59 years [9], and over 80% of all NHLs arising in Waldeyer's ring occur over the age of 50 years [3]. However, as in this study, the disease can affect patients with a very wide age range [9]. Both SCC and NHL may present with a sore throat, dysphagia or lump in the throat or neck. NHL frequently has a rapid onset with a short clinical history of only a few weeks. The presence of systemic symptoms adds support to the diagnosis. However, systemic symptoms were present in only 25% of patients and in general are not a common feature in head and neck lymphomas [10]. The majority of NHL of the tonsil had homogeneous signal intensity the same as normal tonsillar tissue, which is of intermediate signal intensity on T1 weighted images with minimal enhancement after iv gadolinium, and mildly increased signal intensity on T2 weighted images (Figures 1
and 2). Two patients had a mildly heterogeneous tumour and one showed small necrotic foci (Figure 3). Because the majority of tonsillar lymphomas have signal intensity similar to normal tonsillar tissue, the signal characteristics cannot reliably detect disease at this site. In addition, some asymmetry in the size of the tonsils is normal. MRI may therefore not be able to detect early lymphomatous involvement of the tonsil in those patients who undergo MRI for the detection of multifocal disease in Waldeyer's ring or the detection of extranodal sites of lymphoma following the diagnosis of nodal NHL. For those patients presenting with primary tonsillar lymphoma, MRI is used to assess the size of the tumour, the local extent and the presence of nodes, especially those nodes that cannot be detected clinically such as those in the retropharyngeal region. The role of MRI in the assessment of response to treatment will usually depend upon a change in size of the tonsil rather than a change in signal intensity. Tonsillar lymphomas in this study were large at presentation, in accordance with the literature where the average size is 4.6 cm, with some tumours being up to 10 cm [9]. Tumours had a round or lobulated contour similar to the exophytic form of SCC. No tumours in the current study showed deep invasion into the tonsillar fossa. Even large tumours, over 5 cm in size, were well defined and spread superficially along the pharyngeal wall, displacing rather than invading adjacent structures (Figure 3) except in one case where there was invasion of the soft palate. While some lymphomas of the head and neck region may infiltrate soft tissues and bone, this is a more common feature in SCC, where adjacent structures are invaded in 80–95% of cases [7]. The presence of a large tonsillar tumour on MRI, without invasion of adjacent structures, should therefore suggest the diagnosis of tonsillar NHL.
View larger version (137K):
[in this window]
[in a new window]
|
Figure 1. Axial T1 weighted gadolinium enhanced MR image (TR/TE 500/20) of a 41-year-old man demonstrates a well defined rounded left tonsillar non-Hodgkin's lymphoma (arrow). The tumour is of intermediate homogeneous signal intensity similar to the normal tonsil.
|
|
View larger version (173K):
[in this window]
[in a new window]
|
Figure 2. Coronal T2 weighted MR image (TR/TE 2500/100) of a 75-year-old woman demonstrates a right tonsillar lymphoma (arrow) of homogeneous mildly increased signal intensity. Lymphadenopathy is present along the right internal jugular chain (arrowheads).
|
|
View larger version (137K):
[in this window]
[in a new window]
|
Figure 3. Coronal T1 weighted gadolinium enhanced MR image (TR/TE 500/20) of an 84-year-old man demonstrates a large, well defined lobulated left tonsillar lymphoma (arrows) with small necrotic foci, which is displacing local structures.
|
|
Cervical lymphadenopathy is a presenting feature in 15% of cases with extranodal NHL of the head and neck [2]. Tonsillar lymphoma has a higher incidence of cervical nodes than other NHLs in Waldeyer's ring [1, 8]. Cervical lymphadenopathy was present in almost two-thirds of patients in this study. In all cases there was lymphadenopathy in the internal jugular chain, involving the jugulodigastric or upper internal jugular node, ipsilateral to the tonsillar NHL (Figure 2
). Lymphadenopathy was restricted to this site in three patients. The posterior triangle and retro-oropharyngeal and periparotid nodes were involved in the remaining two patients, with bilateral lymphadenopathy in one patient. The distribution of nodal metastases was similar to SCC in the tonsillar fossa, which also tends to affect the jugulodigastric and internal jugular nodes, with the posterior triangle involved 10% of cases and bilateral disease in 22% [11]. The appearance of nodes in NHL was similar to that of the primary tumour, having a predominantly homogeneous intermediate signal intensity on T1 weighted images and mildly increased signal intensity on T2 weighted images, with enhancement after iv gadolinium. Nodal necrosis is uncommon in NHL, unlike SCC [8], but small foci of necrosis were seen in the primary tumour and node of one patient in this study.
Most NHLs of the palatine tonsils are B-cell lymphomas, with a small percentage being of thymic T-cell type [12]. In keeping with NHL of the head and neck in general [1–3, 12–14], tonsillar lymphomas are aggressive tumours of intermediate or high grade [9], frequently of diffuse large cell type. The 5-year survival for disease confined to the tonsil is 86%, but this falls to 41% when lymphadenopathy is present [9]. Relapse is a very poor prognostic indicator and is common, in keeping with other NHLs of Waldeyer's ring [2], the majority occurring within the first 2 years [9]. Relapse most frequently occurs at distant sites, particularly in the non-irradiated lymph nodes of the abdomen as well as in the gastrointestinal tract [9], especially the stomach. The gastrointestinal tract is a common site for distant disease in all patients with NHL of Waldeyer's ring, both at diagnosis and, more frequently, at the time of relapse [2, 13, 15]. Gastrointestinal involvement is found in 20% of patients with NHL of the tonsil [13], and abdominal imaging may be indicated.
In conclusion, NHL arising primarily in the palatine tonsil is uncommon. The diagnosis may be made by tonsillectomy or biopsy before imaging. SCC may be suspected when patients present for imaging with an undiagnosed tonsillar tumour. Features that should alert the radiologist to the diagnosis of NHL are the short clinical history, a large homogeneous tonsillar mass, which despite its size displaces rather than invades local structures, and large homogeneous non-necrotic cervical nodes.
Received for publication June 26, 2000.
Revision received October 12, 2000.
Accepted for publication November 2, 2000.
|
References
|
|---|
-
McGurk M, Goepel JR, Hancock BW. Extranodal lymphoma of the head and neck: a review of 49 consecutive cases. Clin Radiol 1985;36:455–8.[Medline]
-
Jacobs C, Weiss L, Hoppe RT. The management of extranodal head and neck lymphomas. Arch Otolaryngol Head Neck Surg 1986;112:654–8.
-
Saul SH, Kapadia SB. Primary lymphoma of Waldeyer's ring. Clinicopathologic study of 68 cases. Cancer 1985;56:157–66.[Medline]
-
Endo S, Kida A, Sawada U, Sugitani M, Furusaka T, Yamada Y, et al. Clinical analysis of malignant lymphomas of tonsils. Acta Otolaryngol (Stockh) 1996;(Suppl. 523):263–6.
-
Harnsberger HR, Bragg DG, Osborn AG, Smoker WRK, Dillon WP, Davis RK, et al. Non-Hodgkin's lymphoma of the head and neck: CT evaluation of nodal and extranodal sites. AJR 1987;149:785–91.[Abstract/Free Full Text]
-
Otter R, Gerrits WGJ, Sandt MMVD, Hermans J, Willemze R. Primary extranodal and nodal non-Hodgkin's lymphoma. A survey of a population-based registry. Eur J Clin Oncol 1989;25:1203–10.
-
Collins S, Spector GJ. Cancer of the oral cavity, oropharynx and pharynx. In: Ballenger JJ, editor. Diseases of the nose, throat, ear, head and neck (13th edn). Philadelphia, PA: Lea & Febiger, 1985:659–64.
-
DePeña CA, Van Tassel P, Lee YY. Lymphoma of the head and neck. Radiol Clin North Am 1990;28:723–43.[Medline]
-
Barton JH, Osborne BM, Butler JJ, Meoz RT, Kong J, Fuller LM, et al. Non-Hodgkin's lymphoma of the tonsil. A clinicopathologic study of 65 cases. Cancer 1984;53:86–95.[Medline]
-
Yuen A, Jacobs C. Lymphomas of the head and neck. Semin Oncol 1999;26:338–45.[Medline]
-
Civantos FJ, Goodwin WJ. Cancer of the oropharynx. In: Myers EN, Suen JY, editors. Cancer of the head and neck (3rd edn). Philadelphia, PA: WB Saunders, 1996:367–9.
-
Shima N, Kobashi Y, Tsutsui K, Ogawa K, Maetani S, Nakashima Y, et al. Extranodal non-Hodgkin's lymphoma of the head and neck. A clinicopathologic study in the Kyoto–Nara area of Japan. Cancer 1990;66:1190–7.[Medline]
-
Hanna E, Wanamaker J, Adelstein D, Tubbs R, Lavertu P. Extranodal lymphomas of the head and neck. A 20-year experience. Arch Otolaryngol Head Neck Surg 1997;123:1318–23.
-
Economopoulos T, Asprou N, Stathakis N, Fountzilas G, Pavlidis N, Papaspyrou S, et al. Primary extranodal non-Hodgkin's lymphoma of the head and neck. Oncology 1992;49:484–8.[Medline]
-
Banfi A, Bonadonna G, Ricci SB, Milani F, Molinari R, Monfardini S, et al. Malignant lymphomas of Waldeyer's ring: natural history and survival after radiotherapy. BMJ 1972;3:140–3.
This article has been cited by other articles:
|
|
|
|
 
A D King, K I Lei, and A T Ahuja
MRI of neck nodes in non-Hodgkin's lymphoma of the head and neck
Br. J. Radiol.,
February 1, 2004;
77(914):
111 - 115.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. D. King, E. H.Y. Yuen, K. I.K. Lei, A. T. Ahuja, and A. van Hasselt
Non-Hodgkin Lymphoma of the Larynx: CT and MR Imaging Findings
AJNR Am. J. Neuroradiol.,
January 1, 2004;
25(1):
12 - 15.
[Abstract]
[Full Text]
[PDF]
|
|
|
Top
Abstract
Introduction
