✍️ Medical Essay: The Necessity of Excision in Keratoacanthoma
Introduction
Keratoacanthoma (KA) is a rapidly growing cutaneous lesion that often presents as a dome‑shaped nodule with a central keratin plug. Although traditionally considered a benign tumor of hair follicle origin, KA is clinically and histologically difficult to distinguish from squamous cell carcinoma (SCC). This diagnostic uncertainty, combined with its aggressive growth pattern, makes surgical excision the treatment of choice.
Case Context
A 55‑year‑old female with no significant past medical, family, or health history presented with a rapidly enlarging (less than a year) skin lump on the right face, approximately 2 cm anterior to the ear. The lesion was red‑pink, shiny, slightly translucent, with telangiectasia and ulceration at the tip. Excision with appropriate margins was performed, and histology confirmed keratoacanthoma.
Reasons Excision is Necessary
- Diagnostic Uncertainty
- KA and SCC share overlapping clinical and histological features.
- A rapidly growing, ulcerated lesion with vascular changes raises strong suspicion for malignancy.
- Only complete excision and histopathological examination can definitively differentiate KA from SCC.
- Risk of Malignancy
- Although many KAs regress spontaneously, some may evolve into invasive SCC.
- Leaving the lesion untreated risks progression to carcinoma, with potential for local tissue destruction and, rarely, metastasis.
- Rapid Growth and Local Destruction
- KA grows quickly over weeks, causing cosmetic disfigurement and functional impairment, especially on the face.
- Excision prevents further tissue damage and preserves facial aesthetics.
- Ulceration and Secondary Infection
- Ulcerated lesions are prone to infection, bleeding, and patient discomfort.
- Surgical removal eliminates these risks and promotes healing.
- Definitive Treatment and Patient Reassurance
- Excision provides curative management, avoiding the uncertainty of watchful waiting.
- Patients gain reassurance from a clear diagnosis and removal of a potentially malignant lesion.
Conclusion
In this case, excision was necessary due to the lesion’s rapid growth, ulceration, and resemblance to squamous cell carcinoma. Histological confirmation of keratoacanthoma validated the decision. Surgical removal not only ensured diagnostic certainty but also prevented potential malignant transformation, local tissue destruction, and cosmetic compromise. Thus, excision remains the gold standard in managing keratoacanthoma.
✍️ 醫學論文：切除角化棘皮瘤之必要性
引言
角化棘皮瘤（Keratoacanthoma, KA）是一種快速生長的皮膚病灶，常呈現為中央角蛋白栓塞的圓頂狀結節。雖然傳統上被視為毛囊來源的良性腫瘤，但在臨床與組織學上卻難以與鱗狀細胞癌（Squamous Cell Carcinoma, SCC）區分。由於診斷上的不確定性，加上其具侵略性的生長模式，外科切除被視為首選治療方式。
病例背景
患者為 55 歲女性，無重要既往病史、家族史或健康史。右臉靠近耳前約 2 公分處出現一顆快速增大（少過一年）的皮膚腫塊。病灶呈紅粉色、表面光亮、略帶透明，內有明顯毛細血管擴張，頂端伴隨潰瘍。病灶以適當邊界切除後送病理檢驗，結果證實為角化棘皮瘤。
為何必須切除
1. 診斷上的不確定性
- KA 與 SCC 在臨床表現及組織學特徵上高度重疊。
- 快速生長、伴隨潰瘍及血管變化的病灶高度懷疑惡性。
- 唯有完整切除並進行病理檢驗，才能確定區分 KA 與 SCC。
2. 惡性風險
- 雖然部分 KA 可自行退化，但仍有可能演變為侵襲性 SCC。
- 若不予處理，病灶可能進展為癌症，導致局部組織破壞，甚至罕見的轉移。
3. 快速生長與局部破壞
- KA 在數週內即可迅速增大，造成顏面外觀破壞與功能障礙。
- 切除可避免進一步組織損傷，並維持面部美觀。
4. 潰瘍與繼發感染
- 潰瘍性病灶容易感染、出血並造成患者不適。
- 外科切除可消除這些風險並促進癒合。
5. 根治性治療與患者安心
- 切除提供確定性的治療，避免「觀察等待」的不確定性。
- 患者因明確診斷與病灶移除而獲得心理上的安心。
結論
在此病例中，因病灶快速生長、潰瘍及與鱗狀細胞癌相似，切除是必要的。病理證實角化棘皮瘤後，更加肯定了治療決策。外科切除不僅確保診斷正確，也避免了潛在的惡性轉化、局部組織破壞及美觀受損。因此，切除仍是角化棘皮瘤的治療金標準。