Familial cutaneous collagenoma syndrome
FCC is an extremely rare, autosomal dominant condition with approximately 10 affected families reported. Patients typically present at puberty between the ages of 15 and 19 but can develop nodules as early as age 4. One family with FCC demonstrated a splice site mutation in the LEMD3 gene. Different loss of function mutations in LEMD3 are found in Buschke-Ollendorff syndrome, which results in connective tissue nevi but is also associated with bone malformations. Unlike Buschke-Ollendorff syndrome, FCC is not associated with bone defects. However, FCC is infrequently associated with cardiac anomalies and cardiomyopathy.
D21.9 – Benign neoplasm of connective and other soft tissue, unspecified
239139000 – Familial cutaneous collagenoma
Differential Diagnosis & Pitfalls
- Buschke-Ollendorff syndrome – Patients have collagenomas but also osteopoikilosis, which can be identified radiographically.
- Eruptive collagenoma – Associated with multiple collagenomas similar to FCC but has no hereditary predisposition. Nodules in eruptive collagenoma tend to be located on the lower trunk.
- Shagreen patch – This collagenoma is one of the cutaneous manifestations of tuberous sclerosis (TS). Other cutaneous findings of TS include angiofibromas, periungual fibromas, and ash-leaf macules.
- Multiple endocrine neoplasia (MEN) type 1 – Multiple collagenomas, facial angiofibromas, and lipomas are associated with pituitary adenomas, adrenal adenomas, pancreatic endocrine tumors, and hyperparathyroidism secondary to parathyroid hyperplasia.
- White fibrous papulosis of the neck – Papules are generally limited to the neck region and develop in older patients. It is considered a variant of skin aging.