Module 3 - Skin & Soft Tissue Lesions

Benign Soft Tissue Lesions

1.) Cysts

Epidermal inclusion cysts

Epidermal inclusion cysts

Benign cysts lined by epidermal cells
Cyst contains lipid and keratinous material; odorous cheesy material
Smooth, mobile, and firm subcutaneous masses with skin attachment
Removed for diagnosis, prevention of infection, or cosmesis
Excision should include entire cyst lining without interruption as well as any skin tract or drainage site. If infected, drain first with deferral of excision until inflammation has resolved

Ganglion cysts

Subcutaneous, firm, round masses filled with clear viscous fluid
Attach to joint capsule or tendon sheath of hands and wrists
Most common in young and middle-aged women
Removed if symptomatic. Surgical excision of the cyst, its capsular attachment, and a small portion of the joint capsule is the most effective technique for preventing recurrence

2.) Lipomas

Soft, fatty, subcutaneous masses that exist as discrete lobules of varied width
Small, asymptomatic tumours are observed clinically, but those growing rapidly are removed
Little potential for malignancy (<1%), however large tumours (>5 cm) are assessed by incisional biopsy
Atypical lipomas
Usually found deep to fascia, often within muscle, with an infiltrating border
Often classified as low-grade liposarcomas
Excised with a margin of normal tissue because of their higher rate of local occurrence

3.) Fibromata

Neurofibromas

Neurofibromas

Soft, pendulous and sometimes lobulated subcutaneous masses of varying width
Schwann cell origin
Occurrence associated with the autosomal dominant hereditary disease, neurofibromatosis (NF)
5-10% of patients with NF can develop neurogenic sarcomas
For majority of neurofibromas, excision is only performed for when size notably increases or for cosmetic reasons

Dermatofibrosarcoma protuberans

Locally aggressive, non-metastatic malignant tumours
Infiltration of tissue can be so extensive that amputation is required; can be fatal
High recurrence rate despite excision with significant margins of normal tissue (2-5 cm)
Moh’s micrographic surgery is favoured excision strategy
Tumours are relatively radioresistent

Musculoaponeurotic fibromatoses

Dermatofibrosarcoma

Locally aggressive, non-metastatic tumours comprising nodular fasciitis, plantar fibromatosis, and desmoid tumours
Connective tissue origin
Seen in abdominal wall of peripartum women and patients with familial adenomatous polyposis (FAP)
Wide excision with margin of normal tissue if possible, sparing limb function
Tamoxifen and NSAIDs, alone or in combination, is a conservative alternative to surgery

Author: SP Zinn