Introduction: Cutaneous adenocarcinoma over the scalp can arise as a primary neoplasm or as secondary metastases from other primary sources e.g. breast and colon. Primary scalp adenocarcinomas that originate from skin appendages are very rare. They represent a group of tumors with aggressive potential for local tissue infiltration and lymphatic metastases. Due to limited availability of literature, the diagnostic and management approach to these tumors remains a challenge. Here, we present our clinical experience with such patients.
Patient A: A 61-year-old Chinese female presented to us with a 1-year history of painful swelling over her left scalp region. Physical examination showed a 5.5cm lesion with no palpable neck nodes. Imaging studies performed were unremarkable. Polyps biopsied on colonoscopy returned as serrated adenomas. Biopsy of the scalp lesion was reported as poorly differentiated adenocarcinoma. She first underwent a high anterior resection and wide excision of left scalp lesion with rotational flap and split skin graft. The patient subsequently underwent a further wide excision of scalp tumor with partial craniectomy and rotational scalp flap in view of earlier atypical surgical margins. Final report showed a poorly differentiated scalp adenocarcinoma.
Patient B: A 59-year-old Chinese female presented to us with a 5-year history of hair loss over the central scalp area. Physical examination showed a 3cm area of hair loss over the scalp area with no palpable neck nodes. Imaging studies performed were unremarkable and colonoscopy showed a benign rectal polyp. Biopsy of the scalp lesion was reported as adenocarcinoma. She then underwent a wide excision of scalp adenocarcinoma and rotational flap coverage. Final histopathology reported a poorly differentiated scalp adenocarcinoma.
Post operatively, both patients recovered well. Follow up surveillance shows no clinical recurrence at the 9-month stage.
Conclusion: These cases illustrate the diagnostic and management challenges clinicians can face with rare primary scalp adenocarcinomas. It is prudent that a comprehensive metastatic work up be performed before final diagnosis. Clinico-pathological data may be conflicting in several aspects e.g. tumor origin. Hence, it may not be possible to have a clear, distinguishing diagnostic profile for such cases. Based on our experience, a wide excision approach may be adequate and yields desirable survival outcomes. Despite the aggressive potential for lymph nodes spread, there may be place for conservative management without the need for neck dissection in clinically N0 disease patients.