Case Reports

Recurrence of Extranodal Natural Killer/T-cell Lymphoma Presenting as Tarsal Tunnel Syndrome

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  • A thorough review of systems, physical examination, and personal review of a patient’s advanced imaging is critical to avoid missed diagnosis or delays in diagnosis.
  • Any mass lesion encountered in clinical practice, no matter how benign appearing, should be presumed malignant until proven otherwise.
  • Fluorine-18 fluorodeoxyglucose positron emission tomography CT (18-FDG PET-CT) should include whole-body scans when evaluating patients for recurrence of malignancy.




This case report is a rare form of lymphoma recurrence which presented as tarsal tunnel syndrome. The patient had been previously treated for the malignancy and was presumed to be in remission; however, standard radiology imaging protocols failed to include the distal extremities on these scans. The patient presented to the orthopedic clinic with tarsal tunnel symptoms and a mass in the tarsal tunnel. A complete evaluation resulted in a diagnosis of recurrence of the malignancy. This case illustrates the importance of a thorough medical history and personal review of imaging studies, and how a systematic approach can produce the correct diagnosis for any unknown lesion. Furthermore, this case may prompt oncologists to consider obtaining whole-body fluorodeoxyglucose positron emission tomography computed tomography when evaluating for recurrence in patients.

Nasal-type, extranodal natural killer/T-cell lymphoma (ENKTL) is a rare form of non-Hodgkin lymphoma (NHL). Malignancies account for only 10% of NHL in Asian and South American populations. However, in Caucasians, it represents <1% of all cases. In addition, at 3:1 male to female ratio, the disease most commonly affects male patients who are 50 to 59 years old.1-3 The etiology of this malignancy is strongly related to prior infection with Epstein-Barr virus (EBV) as EBV-encoded early small ribonucleic acid on in situ hybridization of lymphoma cells is positive in 95% of cases.4-6

Typical sites of involvement include the nasal cavity, nasopharynx, and sinuses, causing patients to present with nasal obstruction, chronic sinusitis, or epistaxis. Additionally, ENKTL can occur primarily in the skin, gastrointestinal tract, spleen, and testis, whereas the bone marrow may be involved in 10% of cases. Although rare, unusual sites, including muscle, adrenals, and ovaries, have been published.7,8

Staging is best performed using the T-staging system, which accounts for the extent of local tumor involvement. Higher stages, such as T3 /T4, equate to locally advanced disease and imply a worse prognosis.9,10 Computed tomography (CT) and magnetic resonance imaging (MRI) help define local soft tissues and bony involvement. Furthermore, CT of the chest, abdomen, and pelvis as well as bone marrow biopsy are performed as part of the staging process. Lastly, fluorine-18 fluorodeoxyglucose positron emission tomography CT (18-FDG PET-CT) is often used to detect extranodal spread, define the extent of involvement, differentiate between lymphoma and inflammatory masses, and monitor for recurrence.11

Treatment for local ENKTL involves concurrent chemoradiotherapy followed by 3 cycles of etoposide, ifosfamide, cisplatin, and dexamethasone, which results in a complete response rate of 80%, and is the most favorable when comparing treatment modalities.12 Unfortunately, recurrence rates reach as high as 50%, whereas the 5-year survival rate is 59%.13,14 For recurrent or disseminated disease, high-dose chemotherapy and hematopoietic stem cell transplantation remain as alternative treatments for patients who have undergone 2 complete remissions and can be curative in some instances.13,15

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