Analysis of incomplete excisions of basal-cell carcinomas after breadloaf microscopy compared with 3D-microscopy: a prospective randomized and blinded study.

Basal-cell carcinomas may show irregular, asymmetric subclinical growth. This study analyzed the efficacy of 'breadloaf' microscopy (serial sectioning) and three-dimensional (3D) microscopy in detecting positive tumor margins. Two hundred eighty-three (283) tumors (51.2%) were put into the breadloaf microscopy group; 270 tumors (48.8%) into the 3D microscopy group. The position of any detected tumor outgrowths was identified in clock face fashion. The time required for cutting and embedding the specimens and the examination of the microscopic slides was measured. Patient/tumor characteristics and surgical margins did not differ significantly. Tumor outgrowths at the excision margin were found in 62 of 283 cases (21.9%) in the breadloaf microscopy group and in 115 of 270 cases (42.6%) in the 3D microscopy group, constituting a highly significant difference (p < 0.001). This difference held true with incomplete excision of fibrosing (infiltrative/sclerosing/morpheaform) tumors [32.9% in the breadloaf microscopy group and 57.5% in the 3D microscopy group (p = 0.003)] and also with solid (nodular) tumors [16.1 and 34.2%, respectively (p < 0.001)]. The mean overall examination time required showed no important difference. In summary, for detection of tumor outgrowths, 3D microscopy has almost twice the sensitivity of breadloaf microscopy, particularly in the situation of aggressive/infiltrative carcinomas.

Extramammary Paget's disease: extended subclinical growth detected using three-dimensional histology in routine paraffin procedure and course of the disease.

BACKGROUND: Extramammary Paget's disease (EMPD) is a rare tumor of the skin characterized by extended irregular subclinical growth and high recurrence rates after surgery. OBJECTIVE: To show that, using three-dimensional (3D) histology in surgical excision, the size of the safety margin can be individually determined and locally adjusted to subclinical growth and to evaluate the course of the disease in 33 patients. METHODS: The clinical records of 33 patients with primary lesions of EMPD were prospectively documented, retrospectively confirmed, and analyzed. RESULTS: EMPD was found more frequently in women (54.5%). Dermal invasion was found in 21.2%, and regional lymph node metastases were present in one patient; 30.3% of the patients had secondary internal malignancies. In 25 cases examined using 3D histology, a mean surgical margin of 22 mm in asymmetric shape (range 5-65 mm) was achieved, with a recurrence rate of 28%. Surgery with conventional histologic examination had a higher recurrence rate of 62.5% using a mean surgical margin of 19 mm (range 7-40 mm). CONCLUSIONS: Subclinical spread of EMPD demonstrated using 3D histology with paraffin sectioning can be large. Three-dimensional histology allows individually defined safety margins to be locally adjusted to subclinical growth and gives low recurrence rates. The authors have indicated no significant interest with commercial supporters.