Paraneoplastic leukocytosis secondary to carcinosarcoma: a report of two cases and literature review.

ABSTRACT

BACKGROUND: Neutrophilia is an increase in the number of neutrophils over 7.5×103/µL. An increase in leukocytes over 50×103/µL is called a leukemoid reaction; and when it is associated with a solid tumor, it is considered a paraneoplastic syndrome called paraneoplastic leukemoid reaction (PLR). It is a very rare clinical condition and it is very unusual for it to be associated with carcinosarcoma. We present two cases of a leukemoid reaction observed in the Medical Oncology Department of the University Hospital of Salamanca between May and September 2023. The main objectives of our article are to describe the unusual appearance of paraneoplastic leukocytosis at the diagnosis of carcinosarcoma carcinosarcoma, explain in a detailed way its diagnostic procedure and to show the poor prognosis to which it is associated. CASE DESCRIPTION In our presentation, we describe two similar cases first of all, a 60-year-old woman without relevant medical history. She was referred by her primary physician to the Department of Internal Medicine in August 2023 with asthenia, lumbar pain, and weight loss of 12 kg of 3 months of evolution. The physical examination revealed a palpable hypogastric mass. An abdominal, pelvic, and thoracic computed tomography (CT) scan revealed a heterogenous solid mass with necrotic areas originating in the uterus. The anatomopathological diagnosis was carcinosarcoma. The patient showed a progressive worsening in her renal function associated with hyperviscosity secondary to hyperleukocytosis caused by 170×103/µL neutrophils. In the second case we describe the diagnosis of a PLR secondary to a kidney carcinosarcoma. When the patient started chemotherapy, he presented 55.08×103/µL leukocytes, 53.16×103/µL neutrophils. Eight days after receiving chemotherapy, the patient was admitted as an emergency with oligoanuria and decreased consciousness. He presented creatinine 6.25 mg/dL, phosphate 12.4 mg/dL, leukocytes 1.05×103/µL, and neutrophils 0.71×103/µL. The clinical diagnosis was acute exacerbation of multifactorial mixed (renal and prerenal) chronic kidney disease associated with tumor lysis syndrome and grade 3 neutropenia. The patient presented a poor evolution, dying after 2 months. CONCLUSIONS: PLR is a severe paraneoplastic syndrome associated with different types of solid tumors. Its appearance at the time of diagnosis of a tumor implies a poor vital prognosis.