The role and importance of auxiliary tests in differential diagnosis in patients with mildly high basal 17-OH-progesterone levels in the evaluation of hirsutism

BACKGROUND/AIM: In the differential diagnosis of hirsutism, early follicular basal 17-OH-progesterone levels sometimes overlap with the diagnosis of late onset congenital adrenal hyperplasia (LOCAH) and other causes of hyperandrogenism. This study aims to investigate the role of some common tests and clinical findings in differential diagnosis in such cases. MATERIALS AND METHODS: One hundred seventy-five female patients with hirsutism and mildly high initial 17-OH-progesterone levels (2-10 ng/mL) were included in the study. The cases were divided into three groups according to their diagnosis: LOCAH (n = 16, mean age = 26.1 ± 6.9), polycystic ovary syndrome (PCOS) (n = 122, mean age = 23.9 ± 5.1), and intracranial hypertension (IH) (n = 37, mean age = 25.2 ± 7.3). Clinical signs and symptoms, such as menstrual irregularity and hirsutism score, and hormone levels including total testosterone and dehydroepiandrosterone sulfate (DHEAS), were compared between the groups. RESULTS: There was no difference between the groups with PCOS, LOCAH, and IH for total testosterone level results (P = 0.461). The DHEAS level was higher in the PCOS group than in the LOCAH group (449.6 ± 151.14 vs. 360.31 ± 152.40, P = 0.044). While there was no difference between the PCOS and LOCAH groups in terms of menstrual irregularity (P = 0.316), the hirsutism score for IH was significantly lower than those of PCOS and LOCAH (9.2 vs. 12.2 and 11.1, respectively; P < 0.001). Basal 17-OH-progesterone levels were higher in the LOCAH group than in the other groups (P = 0.016). CONCLUSION: While DHEAS level was lower in LOCAH than in PCOS, it was not different from that in IH. While the severity of hirsutism was higher in LOCAH than in IH, it was not different from that in PCOS. Menstrual irregularity was similar between PCOS and LOCAH. According to these results, although the auxiliary tests and clinical findings for the diagnosis of LOCAH contribute to the clinical interpretation, they are not superior to the 17-OH-progesterone level for diagnosis.