Frozen section assessment in testicular and paratesticular lesions suspicious for malignancy: its role in preventing unnecessary orchiectomy.

To investigate the role of frozen section assessment in sparing unnecessary orchiectomy for suspected lesions, we retrospectively reviewed intraoperative testicular and paratesticular frozen section assessments performed at our institution between the years 1993 and 2010. Frozen section assessments were performed on 45 testicular lesions (age, 5-60 [mean, 32.2] years; lesion size, 0.5-9.7 [mean, 2.1] cm) and 20 paratesticular lesions (age, 26-76 [mean, 43.5] years; lesion size, 0.4-11.0 [mean, 2.8] cm) before the decision to complete radical orchiectomy. Benign/malignant frozen section assessment diagnoses were reported in 26/19 testicular cases and 17/3 paratesticular cases, respectively. Of the 26 benign testicular frozen section assessments, 5 cases resulted in orchiectomy, where permanent diagnoses included epidermoid cyst, large cell calcifying Sertoli cell tumor, fibrous pseudotumor, abscesses, and sarcoidosis, caused by a concern for potential malignancy or questionable viability of the testicles. Of the 19 malignant testicular frozen section assessments, orchiectomy was performed in 16 cases with germ cell tumor, but not in the remaining 3 cases with lymphoma. Of the 17 benign paratesticular frozen section assessments, 2 cases, both fibrous pseudotumors, resulted in orchiectomy. There were statistically significant differences in the size of the testicular (P < .001) or paratesticular (P < .001) lesions between benign and malignant frozen section assessments. Thus, in 36 (83.7%) of 43 cases with benign frozen section assessments, in addition to all 3 cases of lymphoma, orchiectomy was successfully avoided. These results suggest that frozen section assessment is useful for permitting testicular preservation, especially in men with small, nonpalpable, incidentally found masses as well as other benign lesions where a clinical diagnosis of malignancy is in doubt.

Diffusion-weighted MRI postoperative assessment of an epidermoid tumour in the cerebellopontine angle.

Cerebellopontine angle epidermoid tumour generally has a typical appearance with conventional MRI sequences. The lesion is irregular in shape and gives slightly higher signal than cerebrospinal fluid on T1- and T2-weighted images, with a characteristic marbled inner pattern on T1-weighted images. Diffusion-weighted imaging (DWI) can be useful for the diagnosis of an atypical epidermoid tumour. Our case report illustrates the usefulness of DWI for postoperative assessment of residual foci of tumour. The specific appearance of an epidermoid tumour is illustrated, with emphasis on apparent diffusion coefficient (ADC) measurements.

Proliferative assessment of craniopharyngioma and epidermoid by nucleolar organizer region staining.

The histologic distinction between craniopharyngioma and epidermoid is equivocal. Eight craniopharyngiomas and ten epidermoids (including three dermoids) as well as nine rat (Wistar) abdominal skins that acted as control were investigated by a silver colloid method for nucleolar organizer regions (Ag-NORs). The mean number of Ag-NORs in at least 200 cells of both basal (columnar) epithelial cells and suprabasal (prickle) cells was evaluated. It was found that the mean number of Ag-NORs in basal cells of epidermoid and rat skin was significantly greater than that in suprabasal cells (P < 0.001 in nine of ten epidermoids and in all rat skins). On the other hand, of eight craniopharyngiomas, the mean Ag-NOR number in basal cells was not significantly different from that in suprabasal cells in five cases, and, further, the former was significantly smaller than the latter in the other three cases (P < 0.01 in two and P < 0.05 in one). These findings suggest that a stepwise maturation of the epithelial cells like that in mammalian skin epidermis exists in epidermoids but not in craniopharyngiomas. In craniopharyngiomas, the maturation of the epithelial cells seems to be considerably limited or lost from the aspect of proliferative potential as assessed by Ag-NOR score, which indicates neoplastic growth of craniopharyngiomas. Ag-NOR staining may thus be a useful method to distinguish craniopharyngioma from epidermoid.