Young Investigator: Metastatic Crohnʼs Disease of the Vulva: A Diagnostic Challenge

Abstract

BACKGROUND: Metastatic Crohn's disease of the vulva is an extraintestinal cutaneous manifestation that occurs less commonly than fistulizing disease. It can be an underdiagnosed entity as it presents in a similar to fashion to other infectious and non-infectious diseases of the vulva. We present a patient with a long history of Crohn's disease that was initially diagnosed as Hidradenitis suppurativa and who underwent prolonged unsuccessful courses of antibiotics before starting appropriate treatment, illustrating the diagnostic difficulty especially in the absence of active Crohn's disease. RESULTS: A 49 year old female with known Crohn's disease presented initially to gynecology clinic with vulvar lesions of one month duration. The patient had a history of hypertension, depression and recurrent pulmonary embolisms. Past surgeries included laparoscopic proctocolectomy, ileostomy and cholecystectomy. Home medications were furosemide, warfarin, sertraline, Lisinopril and gabapentin. She has not been sexually active for the past 10 years. She reported painful bilateral nodular vulvar lesions that increased in size and eventually started to discharge despite use of cephalexin prescribed in urgent care. She feels otherwise well since her last gastrointestinal surgery three years ago. She denied diarrhea, bleeding per rectum, abdominal pain, weight loss, nausea or vomiting. On physical exam she was obese and had normal vitals. Ileostomy was intact. There were tender nodular lesions associated with clear discharge as well as few small sized ulcers on the mons pubis and labia majora. Rest of exam revealed no abnormalities. Complete blood count, comprehensive metabolic panel, erythrocyte sedimentation rate and C-reactive protein were within normal. Cultures from lesions showed growth of Citrobacter freundii complex sensitive to trimethoprim-sulfamethoxazole. Cultures for MRSA and screening for human papilloma virus, syphilis, chlamydia and gonorrhea was negative. During the following three months, she continued taking multiple antibiotics with several visits to gynecologist and referral to infectious diseases and gastroenterology clinics. Her vulvar lesions never improved. Suspicion of an extraintestinal manifestation of Crohn's disease was raised, so she underwent biopsy. This revealed non-caseating granulomas in addition to dilated cystic follicles, some containing keratinous debris, with surrounding lymphoplasmacytic infiltrates and dilated blood vessels in a granulation tissue background. Possible diagnosis of hidradenitis suppurativa was suggested by pathologist. Patient was referred to Medical Center for Vulvar Disease, where biopsy results were reviewed. The expert opinion was more favorable of a Metastatic Crohn's disease. She was started on adalimumab and topical steroids. On follow up one month later, the patient reported significant improvement of her symptoms. Discussion: Metastatic vulvar Crohn's disease is very rare. Approximately one hundred cases have been reported in the literature. It is characterized by the presence of noncaseating granulomas in the vulva and should be differentiated from other etiologies of granulomatous lesions. There is probably an association between Crohn's disease and hidradenitis suppurativa, while both can co-exist, which makes distinguishing between them more difficult. CONCLUSION(S): Metastatic Crohn's disease of the vulva can be misdiagnosed as hidradenitis suppurativa. Fortunately, treatment of both conditions can be similar (antibiotics and anti-TNF alpha). Possible common immunopathological pathways need further clarification.