Mean plasma concentration of nifedipine has been shown to reach maximum values of 160 +/− 49 µg/L after 30 to 60 minutes following oral administration of 10 mg of nifedipine.13 After 8 hours, the mean concentration drops to 3.4 +/− 1.2 µg/L. The clinical response in our patient appeared consistent with the reported pharmacokinetics of the drug, as she was able to consistently obtain considerable reduction in her pain symptoms within 30 minutes of starting nifedipine, coinciding with the period of time it takes for the nifedipine to reach maximum plasma concentrations.13
Interestingly, our patient had worsening pain episodes associated with sun exposure, which typically is not reported as one of the usual triggers for cutaneous leiomyomas. We are not aware of any described mechanisms that would explain this phenomenon.
Importantly, any patient presenting with multiple cutaneous and uterine (if female) leiomyomas should be screened for hereditary leiomyomatosis and renal cell carcinoma syndrome (HLRCC), an autosomal-dominant disorder linked to a mutation in the fumarate hydratase tumor suppressor gene. Clinically, HLRCC patients typically present with multiple cutaneous leiomyomas, uterine leiomyomas, and renal cell cancer (most often type 2 papillary renal cell carcinoma).14 Hereditary leiomyomatosis and renal cell carcinoma syndrome (also known as multiple cutaneous and uterine leiomyomatosis syndrome) previously was thought to be a separate disease entity from Reed syndrome; however, after the same mutation in the fumarate hydratase tumor suppressor gene was found to be responsible for both Reed syndrome and HLRCC, they are now thought to be the same disease process.15
Diagnosis of HLRCC is likely when the patient meets the major criterion of multiple cutaneous piloleiomyomas confirmed histopathologically. Clinical diagnosis of HLRCC is suspected if 2 or more of the following minor criteria are present: type 2 papillary renal cell carcinoma before 40 years of age; onset of severely symptomatic (requiring surgery) uterine fibroids before 40 years of age in females; and first-degree family member who meets 1 or more of these criteria.15 At the time of presentation, the patient met clinical criteria for HLRCC, including multiple cutaneous leiomyomas (major criterion) and type 2 papillary renal cell carcinoma before 40 years of age (minor criterion). The patient also had a history of uterine leiomyomas, but these lesions did not fulfill the criterion of being severely symptomatic requiring surgery. Furthermore, the patient’s mother had similar cutaneous leiomyomas and a history of uterine cancer, which fulfilled additional minor criterion, consistent with an autosomal-dominant inheritance pattern (with variable penetrance) seen in HLRCC. An important issue for counseling and monitoring patients is that premenopausal women with HLRCC are at an increased risk of developing uterine leiomyosarcoma.15 Our patient followed up with an oncologist for tumor surveillance and subsequently underwent genetic testing, which revealed a mutation in the fumarate hydratase gene.
Treatment of painful cutaneous leiomyomas, particularly in patients with HLRCC, remains a therapeutic challenge. Although surgical and/or destructive treatments can provide pain relief for patients who have a limited number of lesions, these options are impracticable when a patient has numerous widespread leiomyomas; therefore, systemic therapies may be more beneficial. Clinicians should be aware of nifedipine, which may be used in combination with gabapentin as a viable treatment option in the management of acute and breakthrough pain associated with cutaneous leiomyomas.
The authors thank Alejandra Encalada, MA, for her assistance in the care and follow-up of the patient.