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Updated: Dec 9, 2025
A 3D Organotypic Melanoma Spheroid Skin Model
Published on: May 18, 2018
Primary Dermal Melanoma (PDM): Histological and Clinical Interdependence to Guide Therapy
Hadas Zamir1,2, Meora Feinmesser2,3, Haim Gutman2,4
136631 Dermatology Clinic, Kupat Holim Clalit, Israel.
Background/Purpose:
This study examined clinical and histological parameters of primary dermal melanoma (PDM) to aid in its distinction from dermal metastasis.
Methods:
Retrospective analysis of a prospective cohort of PDM patients. Includes patients fulfilling the strict histologic criteria for PDM (N = 9) and patients who did not, but clinically, unequivocally had an intradermal melanoma-clinical PDM (cPDM; N = 17).Histopathology slides were re-examined. Prognosticators and outcome measures were compared between groups. Sentinel nodes' retrieval and wide local excision (WLE) were offered to all patients as primary treatment.
Results:
26 patients identified, 15 females with a median age of 69 years (range 3.5-85). Mean Breslow was 7.9 ± 5.7 mm (median 5.8, range 1.8-25.0), and the mean mitotic rate was 4.9 ± 3.8/mm2 (median 4.0, range 0-17). Initial treatment and follow-up were as for cutaneous melanoma. One patient in each group with a palpable stage III underwent primary radical dissection. Sentinel nodes were retrieved in all 20 lymphatic mappings performed and found to be metastatic in 5 (25%) patients. Treatment consisted of completion lymph-node dissection. At a median postoperative follow-up of 62 months (range 8-132), 20 patients were disease-free, including 6 of 7 patients with stage III disease at presentation. Six patients died all of cPDM; 5 of 6 patients had primary ulcerated or epidermal-abutting melanomas.
Conclusions:
This is the first study to highlight cPDM. Diagnosis requires expert pathology review and a tight correlation to the clinical parameters. Patients seem to benefit from WLE with sentinel node retrieval and complete dissection when appropriate. However, clinical guidelines for dissection have changed since the time period of this retrospective review. Based on this series, complete nodal dissection in these melanomas is associated with better than expected outcome, for stage III disease.
Insights
This study distinguished primary dermal melanoma (PDM) from metastasis, finding that patients benefit from wide local excision and sentinel node biopsy. Complete nodal dissection showed promising outcomes for stage III disease.
Area of Science:
- Dermatology
- Oncology
- Pathology
Background:
- Distinguishing primary dermal melanoma (PDM) from dermal metastasis is clinically significant.
- Clinical presentation can mimic metastatic disease, necessitating precise diagnostic criteria.
Purpose of the Study:
- To examine clinical and histological parameters of PDM for differentiation from dermal metastasis.
- To evaluate the outcomes of PDM patients treated with wide local excision and sentinel node procedures.
Main Methods:
- Retrospective analysis of a prospective cohort of 26 patients with PDM (N=9) and clinically diagnosed PDM (cPDM; N=17).
- Histopathology review and comparison of prognosticators and outcomes between groups.
- All patients underwent sentinel node retrieval and wide local excision (WLE); completion lymph-node dissection was performed when indicated.
Main Results:
- The study identified 26 patients with a median age of 69 years. Mean Breslow thickness was 7.9 mm, and mean mitotic rate was 4.9/mm².
- Sentinel nodes were metastatic in 25% of patients. At a median follow-up of 62 months, 20 patients were disease-free.
- Six patients died from cPDM, with 5 having ulcerated or epidermal-abutting primary melanomas.
Conclusions:
- Accurate diagnosis of cPDM requires expert pathology and correlation with clinical findings.
- Patients appear to benefit from WLE with sentinel node retrieval and complete dissection when appropriate.
- Complete nodal dissection in PDM is associated with better outcomes, particularly for stage III disease.
