Leukemoid reaction in a patient with metastatic renal cell carcinoma-rare clinical presentation seen in Nepal: a case report

Leukemoid reaction (increase in leucocyte count >50 ×10 cell/l) occurs due to reactive causes of bone marrow and is diagnosed after excluding the malignant haematological disorder. Leukemoid reaction is a rare clinical presentation in metastatic renal cell carcinoma and is said to have a rare prognosis. This case has had been reported in the line of SCARE criteria. A case of a 35-year-old female with no known previous co-morbidities presented with a history of abdominal pain in the right flank region for 2 months, fever and cough for 2 months. Physical examination showed palpable mass and tenderness in the right flank and investigations showed leukemoid reaction in peripheral blood smear. The patient was initially treated with strong intravenous antibiotics with suspicion of pyelonephritis in another centre, despite which the patient still had elevated leucocyte count and referred to our centre, where the patient was evaluated for elevated leucocyte count and with further investigations, ruled out any malignant haematological disorder. Final diagnosis of renal cell carcinoma was made by renal mass biopsy. The patient underwent targeted therapy with sunitinib. The patient expired and further investigation and follow-up were not possible. The lack of data and evidence of extensive diagnostic tests is the reason we are unable to assume leukemoid reaction as a poor prognostic factor in case of metastatic renal cell carcinoma. The presence of other paraneoplastic syndromes with renal cell carcinoma might have resulted in the poor prognosis that cannot be excluded.