Related Experiment Video
Updated: Aug 9, 2026
Automated Multiplex Immunofluorescence Panel for Immuno-oncology Studies on Formalin-fixed Carcinoma Tissue Specimens
Published on: January 21, 2019
Fine-needle aspiration cytology of a metastatic Merkel-cell carcinoma
1Institute of Pathology, Case Western Reserve University, Cleveland, OH 44106.
Insights
This study details the cytologic features of Merkel-cell carcinoma metastatic to inguinal lymph nodes. Recognizing these specific cell patterns aids in distinguishing it from other skin tumors.
Area of Science:
- Cytopathology
- Oncology
- Dermatopathology
Background:
- Merkel-cell carcinoma (MCC) is a rare and aggressive skin cancer.
- Metastasis to regional lymph nodes is common in MCC.
- Accurate cytologic diagnosis is crucial for patient management.
Observation:
- Cytologic smears from inguinal lymph nodes showed highly cellular samples.
- Cells were small to medium-sized, discohesive or in single-cell patterns, with clusters around blood vessels.
- Nuclei were uniform, round to oval, with fine, powdery chromatin and small micronucleoli.
Findings:
- Scanty cytoplasm and abundant intermediate filament "buttons" were noted.
- Frequent mitotic figures and individual cell necrosis were observed.
- Rosette formation was rare, distinguishing it from other small-cell tumors.
Implications:
- These cytologic features are key for differentiating MCC metastasis from other small-cell neoplasms.
- Early and accurate diagnosis improves therapeutic strategies for MCC.
- Understanding metastatic patterns aids in prognosis and treatment planning.
Abstract:
The cytologic features of Merkel-cell carcinoma metastatic to inguinal lymph nodes are described. The primary tumor was in the buttocks. The cytologic smears from the inguinal lymph node were highly cellular, with small to medium-sized cells in a predominantly discohesive or single-cell pattern, as well as large clusters surrounding segments of capillary-sized blood vessels. The nuclei were uniform, round to oval, with delicate nuclear membranes. The chromatin pattern was fine and "powdery" with multiple small micronucleoli. The cytoplasm was very scanty. Intermediate filament "buttons" were abundant. Rosette formation was very rare. Frequent mitotic figures and individual cell necrosis were observed. These features are helpful in the differential diagnosis from other small-cell tumors that may involve the skin.
