[Neuroendocrine (Merkel cell) skin cancer. Electron microscopic study]

Area of Science:

• Dermatopathology
• Oncology
• Cell Biology

Background:

• Neuroendocrine (Merkel cell) carcinoma of the skin is a rare and aggressive skin cancer.
• Understanding its cellular origin and ultrastructural characteristics is crucial for diagnosis and treatment.

Observation:

• Two cases of neuroendocrine (Merkel cell) carcinoma presented with widespread intra- and subcutaneous nodules.
• Histological examination revealed predominantly trabecular tumor patterns.
• Electron microscopy identified key ultrastructural features including neuroendocrine secretory granules, intermediate fibers, Golgi complexes, and basal membrane fragments.

Findings:

• The presence of neuroendocrine secretory granules and other organelles supports the classification of these tumors.
• Ultrastructural analysis revealed specific cellular components consistent with neuroendocrine differentiation.
• Basal membrane fragments were observed, offering clues to tumor structure and behavior.

Implications:

• The findings suggest a potential origin of neuroendocrine (Merkel cell) carcinoma from polypotential epithelial stem cells.
• Further research into the stem cell origin could inform targeted therapies.
• Detailed ultrastructural analysis aids in accurate diagnosis and understanding tumor biology.