9. Lactate Dehydrogenase as a Marker of Ovarian Torsion

Abstract

<h3>Background</h3> Ovarian torsion is a clinical diagnosis, as physical exam and imaging are typically variable and nonspecific. However, ovarian torsion is an emergency requiring immediate surgical intervention. Currently there are no laboratory tests that reliably assist in the diagnosis of ovarian torsion. Lactate dehydrogenase (LDH) is routinely used as a marker of potential malignancy in patients with ovarian masses, but has never been studied as a tool to aid in the diagnosis of ovarian torsion. Given that LDH has been shown to be a marker of tissue necrosis in other emergent conditions such as myocardial and bowel infarction, the use of LDH as a marker for ovarian torsion is plausible. This study is the first to address the potential association between elevated LDH and ovarian torsion. <h3>Methods</h3> A retrospective chart review of female patients under 21 years old who underwent operative management of ovarian masses was performed at a large academic children's hospital. Patients were identified using hospital operative records over a 15 year period. Patients were included if they had undergone any surgery for ovarian mass and had preoperative LDH drawn within 2 days of operative procedure. Preoperative symptoms, preoperative ultrasound findings, intraoperative findings including the presence or absences of ovarian torsion, and pathology were recorded. Univariate and multivariable analyses were completed. <h3>Results</h3> 302 charts were reviewed and 50 met inclusion criteria. Of those included, 13 (26%) had intraoperative evidence of ovarian torsion and 37 (74%) did not. Most had benign final pathology, although 9 (18%) had borderline or malignant tumors. None of the cases with borderline or malignant tumors had intraoperative findings of ovarian torsion and the mean preoperative LDH was 2124 units/liter (SD 4158, 95% CI 0-4842). For patients without evidence of borderline tumors or malignancy on pathology, there was a statistically significant (p=0.005) difference in preoperative LDH with mean LDH of 250 units/liter (SD 97, 95% CI 197-303) and 168 units/liter (SD 38, 95% CI 154-182) for ovarian torsion and no evidence of ovarian torsion, respectively (Figure 1). In patients with torsion and lower than expected LDH (n=3), there were no significant differences in preoperative symptoms, ultrasound findings of size and character of mass, or final pathology compared to those with torsion and elevated LDH; the same was true for patients without torsion and higher than expected LDH (n=7) compared to those without torsion and lower LDH. <h3>Conclusions</h3> LDH can be mildly elevated in cases of ovarian torsion with ovarian mass. Further research, including prospective studies are needed to validate use of LDH in the emergency setting for the diagnosis of ovarian torsion.