Opposed evolution of the osseous and soft parts of progestin-associated osteomeningioma after progestin intake discontinuation

Numerous studies have confirmed a strong association between progestins and meningiomas and the regression and/or stabilization of meningiomas after discontinuation of treatment. Osteomeningiomas represent a small subgroup of meningiomas that appear to be more common among progestin-related meningiomas. However, the specificity of the behavior of this subset of meningiomas after discontinuation of progestin has not yet been assessed. Thirty-six patients (mean age 49.5 years) who presented with at least one progestin-related osteomeningioma (48 tumors total) were identified from a prospectively collected database of patients and had been referred to our department for meningioma and had documented use of cyproterone acetate, nomegestrol acetate, and/or chlormadinone acetate. Hormonal treatment was stopped at the time of diagnosis for all the patients, and the clinical and radiological evolution of this subgroup of tumors was evaluated. For half of the 36 patients, treatment was prescribed for signs of hyperandrogenism, such as hirsutism, alopecia, or acne. Most lesions were spheno-orbital (35.4%) or frontal (31.2%). Although the tissular part of the meningioma shrank in 77.1% of cases, the osseous part exhibited discordant behavior with 81.3% showing volume progression. The combination of estrogens, as well as the prolonged duration of progestin treatment, seems to increase the risk of progression of the osseous part after treatment discontinuation (p = 0.02 and p = 0.028, respectively). No patient required surgical treatment at diagnosis or during the study. These results show that while the soft intracranial part of progestin-related osteomeningioma tumor is the most likely to regress after treatment discontinuation, the bony part is more likely to increase in volume. These findings suggest the need for careful follow-up of these patients, especially those with tumors near the optical apparatus.