A multinucleate cell angiohistiocytoma (MCA) is a benign fibrohistiocytic and vascular cutaneous proliferation characterized by one or more well-circumscribed, erythematous to violaceous papules or nodules. MCAs are rare and have been reported more commonly in women in many studies, including the largest systematic literature review of MCAs, in which 79% of patients were women. The mean age of onset is 50-56 years. MCA lesions typically develop gradually over weeks to months, and most lesions are present for years before a definitive diagnosis is made.
Although the etiology is largely unknown, MCAs are thought to be reactive, with several case reports describing them arising in association with neoplasms, inflammatory processes, or trauma. Studies have also demonstrated a potential role of hormonal signaling, with increased expression of estrogen receptor alpha identified within MCAs. Some experts have also proposed that MCAs are on a spectrum of fibrohistiocytic proliferations that also includes dermatofibromas and fibrous papules, but this remains controversial.
Multinucleate cell angiohistiocytoma
Alerts and Notices
Synopsis
Codes
ICD10CM:
D23.9 – Other benign neoplasm of skin, unspecified
SNOMEDCT:
21985009 – Fibrohistiocytic proliferation of the skin
D23.9 – Other benign neoplasm of skin, unspecified
SNOMEDCT:
21985009 – Fibrohistiocytic proliferation of the skin
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Diagnostic Pearls
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Differential Diagnosis & Pitfalls
Clinically, MCAs may resemble:
- Angiofibromas – Usually occur on the face and are often associated with tuberous sclerosis.
- Dermatofibromas – Usually occur on the leg and dimple centrally with lateral compression (Fitzpatrick sign).
- Granuloma annulare – Usually occurs on the extremities; often forms annular lesions without scale or other epidermal changes. When broadly disseminated, granuloma annulare may be associated with diabetes, while MCAs are not.
- Kaposi sarcoma (KS; AIDS-associated and non-AIDS-associated) – Classic KS typically forms on the legs of elderly men, and epidemic KS is associated with HIV infection. KS is caused by infection with human herpesvirus type 8 (HHV-8). It usually appears more purple.
- Sarcoidosis – Most common in African Americans from the southern United States. It may be associated with pulmonary or other systemic involvement, whereas MCAs are not.
- Flat wart – Groups of skin-colored to pink, small papules caused by human papillomavirus (HPV) that are most common in children. Unlike MCAs, flat warts may develop quickly and often spontaneously regress.
- Lichen planus – Look for grayish-white streaks (Wickham striae) overlying flat, purple papules.
- Venous lake – Dark blue to violaceous papules representing dilated venules; most common on the lip or ear in older patients.
Best Tests
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Therapy
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References
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Last Reviewed:07/09/2020
Last Updated:07/09/2020
Last Updated:07/09/2020
Multinucleate cell angiohistiocytoma