Histopathological work-up and interpretation of sentinel lymph nodes removed for vulvar squamous cell carcinoma.
OBJECTIVE
To evaluate the work-up of sentinel lymph nodes (SLNs) removed for vulvar pT1-pT2 squamous cell carcinoma (SCC). Inguinal lymphadenectomy yields metastases in only 30% of cases. Patients with missed inguinal disease, however, have a risk of dying from systemic disease. SLN dissections reduce morbidity, but work-up should reliably identify metastatic disease.


RESULTS
All SLNs removed from 38 patients with pT1-pT2 SCC and clinically negative inguinal lymph nodes were submitted for frozen section analysis. When negative, SLN were formalin-fixed, sectioned entirely at 330-microm intervals to produce three slides per millimetre [two haematoxylin and eosin (H&E) stained slides; one slide for immunohistochemistry]. If screening of H&E-stained sections was negative, all remaining slides were subjected to immunohistochemistry with an antibody to cytokeratin. Twenty-five of 38 patients (66%) were pN0, 7/38 (18%) had metastases on frozen sections/H&E stains. Immunohistochemistry detected micrometastases in two patients and single tumour cells and anucleate cell structures in four patients. In 12/13 patients the SLN metastases, including all single-cell deposits, were from lichen sclerosus (LS)-associated SCC. Twelve of 13 patients with metastases had a pT2 SCC.


CONCLUSIONS
Micrometastases and single tumour cell deposits in SLNs are typical of LS-associated vulvar SCC. Single tumour cell deposits in SNLs should be regarded as 'positive'. Identification requires serial sectioning and immunohistochemical analysis of all removed SLNs.
Regauer
Sigrid
S
Institute of Pathology, Working groups of Dermatopathology and Gynaecopathology, Medical University Graz, Auenbruggerplatz 25, Graz A-8036, Austria. sigrid.regauer@medunigraz.at
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000601:surgery; D005260:Female; D005629:Frozen Sections; D006801:Humans; D007150:Immunohistochemistry; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000737:chemistry* / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis / Q000473:pathology; D008875:Middle Aged; D009367:Neoplasm Staging; D017410:Practice Guidelines as Topic; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D014846:Vulvar Neoplasms / Q000473:pathology* / Q000601:surgery