TUMOR OF DISTAL TIBIA - MASQUERADING AS TENOSYNOVITIS IN AN
ELDERLY FEMALE - A CASE REPORT
Authors: Mathew Stani 
Published: January 2020

INTRODUCTION : Primary bone lymphoma is a rare disease, accounting for about 3% of all primary bone malignancies in adults. Patients with
primary NHL of bone commonly present with local bone pain, soft tissue swelling, and a mass or a pathological fracture. There is a slight male
preponderance, and most patients are over 45-50 years of age. Primary NHLof bone can arise in any part of skeleton, but long bones (femur) is the
most common sites of presentation but distal tibia is an unusual,rare site of presentation. The outcome of patients with primary lymphoma of bone is
relatively favorable with multidrug regimen chemotherapy +/- radiation therapy
CASE PRESENTATION : A50 year old female presented with chief complaints of pain and swelling over the left leg since 2 months, which was
insidious in onset , gradually progressive in nature and with low grade intermittent fever since 1 month. There was no preceding history of trauma,
joint stiffness or other associated constitutional symptoms. She had an episode of enteric fever 2 months ago, which was treated with IV
antibiotics. She gives history of chemo-radiation for oral malignancy 17 years back, the details of which were not available to us at presentation.
She has also undergone hysterectomy 14 years back, following which she had no complications. On general examination, patient had stable vitals,
with no pallor or generalised lymphadenopathy. She had left sided non-pitting pedal edema upto the level of mid-calf.
On examination of the right leg, we found that she had multiple localized swellings noted over the distal third of leg. The skin over the swelling
was normal, with no wounds, scars, sinuses or dilated veins over the leg. On palpation, there was local rise of temperature with tenderness over the
left leg swelling. The swelling had a smooth surface with ill-define margins, soft in consistency with no evidence of crepitus or abnormal
movements. Peripheral pulsations were well palpated, and there was no sensory or motor deficits. On movement of left ankle joint, the terminal
movements were painful and restricted.Patient was investigated further, where routine blood investigations and X-rays were done, which were
found to be inconclusive.MRI of right leg was done to rule out soft tissue infections or osteomyelitis - which revealed a large infiltrative soft tissue
lesion over the ankle and lower one third of right leg encasing the tendons, distal tibia and fibula , muscles, skin and subcutaneous tissue with
cortical erosions and marrow edema in distal tibia and fibula. Adifferential diagnosis of synovial sarcoma or metastasic lesion to distal tibia/fibula
was suggested based on the MRI report.In view of features suggestive of metastasis, oncology opinion was sought, where they advised USG
abdomen and pelvis & chest x-ray.USG abdomen and pelvis was suggestive of bilateral metastases to adrenal glands with retroperitoneal
lymphadenopathy. To confirm the same, CECT abdomen and pelvis , with thorax screening was ordered. This revealed multiple retroperitoneal
enlarged lymp nodes with multiple metastases to adrenal and kidneys. Hence, we considered a possibility of lymphoma based on these finding.For
the purposes of staging, bone marrow aspiration and biopsy was done, which was found to be normal.With all preliminary investigation done to
diagnose the primary lesion, it was decided to perform a biopsy of the lesion from left distal tibial metaphysis and soft tissue
swelling.Histopathology revealed a lympho proliferative lesion suggestive of Non Hodgkin`s Lymphoma.Immunohistochemistry markers were
ordered on the histopathology specimen, which showed positivity for CD 45, CD 20 , Ki 67 and was confirmed to have Diffuse Large B cell
Lymphoma.Patient was then referred to the Oncology department for chemotherapy. Patient is on regular follow-up since then, and remains
asymptomatic.
CONCLUSION: Primary lymphoma of the bone involving distal tibia is a very rare entity, with chemotherapy and radiotherapy being the
mainstay of treatment. Surgery has a limited role.Early diagnosis and treatment can help reduce significant morbidity and mortality