Autosomal-Dominant Familial Angiolipomatosis

Angiolipomas most often occur sporadically; however, family history has been identified in a minority of cases. This rare finding has been classified as familial angiolipomatosis (Online Mendelian Inheritance in Man [OMIM] 206550), which can be inherited in either anautosomal-recessive or very rarely in an autosomal-dominant fashion.² Our patient had numerous relatives with a history of similar lesions, which supported the diagnosis of familial angiolipomatosis in an autosomal-dominant inheritance pattern (Figure 1). Patients with autosomal-dominant familial angiolipomatosis also have been described to have other coincidental medical conditions, such as polycystic kidney disease.¹⁰

The clinical presentation of familial angiolipomatosis includes multiple subcutaneous tumors and a family history of similar lesions that are not associated with malignant transformation. Subcutaneous tumors and a family history with autosomal-dominant inheritance also can be seen in neurofibromatosis type I, which is associated with various benign and malignant neoplasms (eg, meningiomas, gliomas, pheochromocytomas). Therefore, in familial cases of multiple subcutaneous tumors transmitted in an autosomal-dominant pattern, histologic examination is essential to establish the correct diagnosis. Goodman and Baskin¹¹ reported a patient with familial angiolipomatosis who initially was suspected to have neurofibromatosis. The patient also had a granular cell tumor, which occasionally can be seen in neurofibromatosis.¹¹ Another diagnostic problem between familial angiolipomatosis and neurofibromatosis was described by Cina et al² who documented a case of familial angiolipomatosis with Lisch nodules, which are common in neurofibromatosis but rarely are seen in patients without this condition.¹² These reported parallels have prompted some investigators to suggest that similar pathogenetic mechanisms might be involved in both familial angiolipomatosis with an autosomal-dominant inheritance and neurofibromatosis type I.¹¹ Karyotyping performed on angiolipomas has failed to reveal reproducible cytogenetic abnormalities,¹³ with the exception of 1 report that documented a patient in which 1 of 5 angiolipomas had a t(X;2) abnormality.¹⁴ Conversely, ordinary lipomas are associated with numerous karyotypic abnormalities.¹⁴

Angiolipomas are benign tumors, but patients with large or disfiguring angiolipomas may choose to undergo surgical excision. For neoplasms that deeply extend between muscles, tendons, and joint capsules, subtotal excision may be required to restore regular function; however, local recurrence with muscular hypotrophy and deformation of the bones near the affected joints may occur.¹⁵

Conclusion

We present the case of a 31-year-old man with a rare form of familial angiolipomatosis characterized by an autosomal-dominant inheritance pattern. Our case emphasizes the need to obtain a detailed family history to determine the inheritance pattern in patients with multiple lesions of angiolipoma. Pathology review is essential to differentiate other diseases such as neurofibromatosis, which may present in a similar fashion. We encourage reports of further cases of familial angiolipomatosis to document the inheritance patterns.