Figure 1
Sacro-iliac joint
Clinical History
The patient presented with trigeminal neuralgia, a rapidly enlarging thyroid mass and back pain.
Imaging Findings
The patient presented to the orthopaedic clinic with a six-month history of low back pain and right-sided sciatica. Initial plain films and bone scan did not show any abnormalities (not shown). A few months later pain was localised to the right sacroiliac joint and a CT scan showed patchy sclerosis and lysis in the right iliac bone, suggestive of neoplasm, particularly the possibility of lymphoma.
The patient developed sensory loss on the right side of the face involving all three divisions of the trigeminal nerve. She also had a rapidly enlarging thyroid mass. MRI of the brain and neck was performed and an initial diagnosis of a schwannoma of the trigeminal nerve was made. In addition, a large well-defined mass was demonstrated within the right lobe of thyroid gland and a few 1-cm nodes were also demonstrated on the right side of the neck. She went on to have a thyroidectomy. Histology confirmed high-grade B-cell non-Hodgkin's lymphoma (NHL).
Discussion
Non-Hodgkin's lymphoma accounts for 3% of all newly diagnosed cancers. It can affect all age groups and males are affected more frequently than females (1.4:1). 60% originate in lymph nodes; the rest are in extra-nodal sites. 85% of cases are B-cell and the rest are T-cell NHL. The central nervous system is involved in 2-3% of cases of systemic lymphoma. Isolated trigeminal neuropathy is not a common presentation of secondary lymphoma of the central nervous system.
MRI provides direct multiplanar imaging. The signal intensity of the cellular deposits of lymphoma typically remains hypo- to iso-intense on all sequences. Contrast makes these lesions more prominent. Contrast CT will also show leptomeningeal deposits. In this case, a presumptive diagnosis of trigeminal schwannoma was made on the basis of the clinical symptoms and MRI findings (smooth masses, iso-intensity on T1- and high intensity on T2-weighted imaging with and without enhancement). Similar MRI signals are demonstrated in trigeminal lymphoma (Khaled et al.).
In this case, the rapid growth of the trigeminal nerve lesion within 3 weeks suggested a malignant nature rather than a slow-growing schwannoma. The simultaneous lesion in the thyroid gland allowed an easy route for excisional biopsy and histology which confirmed the B-cell NHL. The trigeminal nerve lesion showed a rapid responce to chemotherapy and complete resolution with a combination of chemotherapy and radiotherapy proved that it was secondary to the systemic NHL. Lymphomas seem to be able to mimic most disease entities. Nowadays, with the increasing prevalence of both primary and secondary lymphomas, we should consider the possibility of lymphoma in the differential diagnosis.
Differential Diagnosis List
Non-Hodgkin's lymphoma
Final Diagnosis
Non-Hodgkin's lymphoma
References
[1]
Abdel Aziz KM, van Loveren HR. Primary lymphoma of Meckel's cave mimicking trigeminal schwannoma: case report.
Neurosurgery. 1999 Apr;44(4):859-62; discussion 862-3. (PMID: 10201312)
[2]
Manon-Esapillat R, Lanka R, Ruff L, Masaryk T.
Visualisation of isolated trigeminal nerve invasion by lymphoma using gadolinium-enhanced MRI. Neuroradiology 1990;32:531-2. (PMID: 2287390)
[3]
Hochberg F, Miller D.
Primary Central nervous system lymphoma. Neurosurgery 1998;68:835-53. (PMID: 3286832)
[4]
Zimmerman R
Central nervous system lymphoma. RCNA 1990 July;28(4):697-721. (PMID: 2190266)
[5]
Dahnert W.
Chest disorders.
In Radiology Review Manual (fourth edition)
Williams & Wilkins, Baltimore, pp 420-1 (1999).
Case information
| URL: | https://eurorad.org/case/1241 |
| DOI: | 10.1594/EURORAD/CASE.1241 |
| ISSN: | 1563-4086 |
Figure 2
Post-contrast MRI
This sagittal post-contrast T1-weighted image shows the enhancing mass at Meckel's cave (arrow). The swelling of the nerve can be traced proximally along the nerve through the pre-pontine cistern to the root entry zone. It can be traced distally extending into the inferior cavernous sinus (along the maxillary division), and inferiorly through the foramen ovale into the masticator space (mandibular division) to the medial aspect of the mandibular ramus (inferior alveolar nerve).
Coronal post-contrast T1-weighted image. The swelling of the nerve can be traced proximally along the nerve through the pre-pontine cistern to the root entry zone. It can be traced distally extending into the inferior cavernous sinus (along the maxillary division), and inferiorly through the foramen ovale into the masticator space (mandibular division) to the medial aspect of the mandibular ramus (inferior alveolar nerve).
Axial post-contrast image. The swelling of the nerve can be traced proximally along the nerve through the pre-pontine cistern to the root entry zone. It can be traced distally extending into the inferior cavernous sinus (along the maxillary division), and inferiorly through the foramen ovale into the masticator space (mandibular division) to the medial aspect of the mandibular ramus (inferior alveolar nerve).
Axial post-contrast T1-weighted scan through the neck demonstrating the enhancing thyroid mass as well as the enlarged lymph nodes (not seen at this level).
Post-contrast MRI
This sagittal post-contrast T1-weighted image shows the enhancing mass at Meckel's cave (arrow). The swelling of the nerve can be traced proximally along the nerve through the pre-pontine cistern to the root entry zone. It can be traced distally extending into the inferior cavernous sinus (along the maxillary division), and inferiorly through the foramen ovale into the masticator space (mandibular division) to the medial aspect of the mandibular ramus (inferior alveolar nerve).
Coronal post-contrast T1-weighted image. The swelling of the nerve can be traced proximally along the nerve through the pre-pontine cistern to the root entry zone. It can be traced distally extending into the inferior cavernous sinus (along the maxillary division), and inferiorly through the foramen ovale into the masticator space (mandibular division) to the medial aspect of the mandibular ramus (inferior alveolar nerve).
Axial post-contrast image. The swelling of the nerve can be traced proximally along the nerve through the pre-pontine cistern to the root entry zone. It can be traced distally extending into the inferior cavernous sinus (along the maxillary division), and inferiorly through the foramen ovale into the masticator space (mandibular division) to the medial aspect of the mandibular ramus (inferior alveolar nerve).
Axial post-contrast T1-weighted scan through the neck demonstrating the enhancing thyroid mass as well as the enlarged lymph nodes (not seen at this level).