Ovarian Sarcomatoid Carcinoma Presenting with Paraneoplastic Leukemoid Reaction: Case Report

Background: Sarcomatoid carcinoma is an aggressive, rare malignancy that can arise as mural nodules in the presence of other primary ovarian malignancies. Associated with sarcomatoid carcinomas of other organs, paraneoplastic leukemoid reaction (PRL) is a rare syndrome of extreme hyperleukocytosis, usually greater than 50 k/ul, that arises in the absence of a primary hematologic malignancy and characteristically resolves following tumor removal. Case Presentation: A 57-year-old female presented with vague gastrointestinal symptoms and was incidentally found to have white blood cell (WBC) of 56.4 k/ul, with a negative work-up for hematologic malignancy. Abdominal CT imaging demonstrated a large abdominal mass and biopsy confirmed a diagnosis of sarcomatoid carcinoma, clinically favored to be of ovarian origin. Treatment consisted of surgical resection of the large (32 x 30 x 17 cm) mass, left salpingo-oophorectomy, and radical small bowel resection. Notably, the patient’s WBC count fell from 175 k/ul, on the morning of surgery, to 17.3 k/ul, days after tumor resection. Conclusion: We report a rare case of sarcomatoid carcinoma of probable ovarian origin, presenting with extreme leukocytosis and characteristic behavior of PRL. Sarcomatoid carcinoma and PRL are both, individually, associated with a poor prognosis. Accurate diagnosis is essential to ensure minimal delay in initiating treatment.