DLBCL

Published case study – First case of DLBCL presenting as bilateral internal auditory canal lesions and mimicking bilateral schwannomas

Last month, in a Letter to the Editor of the Canadian Journal of Neurological Sciences, Nevena Markovic from Western University London, Ontario, Canada, and colleagues reported a case of a male patient, 47 years of age, who was referred due to subacute unilateral hearing loss.

Key Highlights:

Clinical History:

  • One-week history of disequilibrium and progressive left-sided hearing loss; not associated with headache, tinnitus, or vertigo
  • Two days before assessment, patient experienced weakness of the right side of his face
  • Vital signs were stable
  • Cranial nerve examination revealed normal extraocular movements and visionary fields
  • Unremarkable funduscopy, motor and somatosensory, and systemic examinations
  • Blood cell count, chemistry, LDH, creatinine, and liver enzymes all within normal limits
  • Negative for ESR, CRP, ENA, ANA, c-ANCA, and p-ANCA inflammatory/autoimmune markers
  • Finger-to-nose and heel-to-shin tests were normal
  • Bilateral mild lower motor neuron facial palsies, more prominent on the right
  • Audiometry showed complete sensorineural hearing loss on the left
  • Difficulties performing tandem gait
  • MRI:
    • Bilateral Internal Auditory Canal (IAC) and cerebellopontine angle masses
    • Right measuring 14mm and left measuring 16mm in length
    • Images reported as bilateral cerebellopontine angle schwannomas
  • Lumbar puncture identified elevated nucleated cells at 28×106/L with 81% lymphoid predominance in the Cerebrospinal Fluid (CSF)
  • Flow cytometry found monoclonal B-cell population accounting for approx. 3% of total leukocytes
  • Cytology showed highly cellular aspirate containing a few atypical lymphocytes
  • Bone marrow biopsy was not indicative of a B-cell lymphoproliferative neoplasm
  • CT showed a round soft-tissue mass (3.5x3.8cm) abutting the right kidney
  • CT-guided biopsy of the mass identified Diffuse Large B-Cell Lymphoma (DLBCL) pathology

Treatment and Outcome:

  • Received six cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, methotrexate, and prednisone (R-CHOMP) with intrathecal methotrexate
  • At 4-months (midway through chemotherapy):
    • CT identified significant improvement with only focal soft-tissue thickening remaining in the right perirenal space
    • MRI of brain found complete resolution of enhancement of bilateral IAC lesions
  • At 6-months (chemotherapy completion), PET showed no evidence of hypermetabolic lesions to suggest ongoing disease
  • At 2-years post-diagnosis, the patient continues to show no signs of clinical recurrence
  • Hearing in the left ear improved to moderate loss on repeat audiology testing

The group state that, to their knowledge, this is the first published case of a DLBCL presenting as bilateral IAC lesions and mimicking bilateral schwannomas. The authors noted that this case responded well to R-CHOMP chemotherapy, with no evidence of recurrence after 2 years. They hypothesize the quick diagnosis from initiation of symptoms and rapid treatment initiation may have contributed to the excellent response.

Abstract:

N/A

References
  1. Markovic N. et al. Diffuse Large B-Cell Lymphoma Presenting as Bilateral Internal Auditory Canal Lesions. The Canadian Journal of Neurological Sciences. 2017 Sep;44(5):621-623. DOI: 10.1017/cjn.2017.23. Epub 2017 Apr 27.