ObjectiveThe aim of the study was to assess for the presence of vulvar lichen planus (LP) in association with human papillomavirus (HPV)–independent squamous cell carcinoma (SCC).Materials and MethodsWe performed a clinicohistopathologic review of consecutive vulvectomies and wide local excisions for HPV-independent vulvar or vaginal SCC from 2007 to 2017. Data collected included site of SCC, adjacent precursor lesions and dermatoses, dermatologic treatment, and outcome.ResultsThere were 43 cases of primary HPV-independent vulvar SCC treated by excision, but no vaginal cancers. Eighteen women (42%) had a preoperative diagnosis of lichen sclerosus (LS); none had a diagnosis of LP. Topical corticosteroids were prescribed in 19 (44%) of 43, with 4 women placed on maintenance therapy. Tumors arose from the labia minora, labia majora, and periclitoris, but not from vestibule or perianus. On histopathological review, LS was present in 41 (95%) of 43 specimens, 1 had a nonspecific lichenoid reaction, and 1 had lichen simplex; both of the latter had subsequent biopsies showing LS. Lichen planus was not seen in association with SCC. Differentiated vulvar intraepithelial neoplasia (dVIN) was present in 38 (88%) of 43 specimens, whereas 1 had acanthosis with altered differentiation and 4 (9%) had no precursor lesion. Differentiated vulvar intraepithelial neoplasia had standard, basaloid, and hypertrophic morphology, superficially resembling erosive LP in 9 (24%) of 38 and hypertrophic LP in 6 (16%) of 38.ConclusionsLichen planus was not seen in association with HPV-independent vulvar SCC, whereas LS was underrecognized and inadequately treated in this group. Pathologists should be aware that dVIN may superficially resemble erosive or hypertrophic LP.

Vulvar LP on keratinized skin has a diversity of appearances and presents a clinicopathologic challenge. Further research is required to understand the natural history of hypertrophic LP and the underlying diagnosis of nonspecific lichenoid cases.

Background: Atypical breast cytology is a poorly understood heterogeneous category with limited clinical utility but significant implications for patient management. Objective: To provide an insight into the true nature of atypical breast cytology in screening-detected (asymptomatic) and symptomatic settings, and find strategies for reducing the use of this diagnostic category. Materials and Methods: A total of 6,415 breast cytology samples were processed between January 2004 and December 2008. An atypical cytological diagnosis was rendered in 256 (4%) of the cases. A blind microscopic review of the atypical cases was conducted and results were correlated with subsequent histological and/or clinical outcomes. Results: Follow-up information by histology was available in 85.5%, by repeat fine-needle aspiration (FNA) in 3.5% and by imaging or clinical follow-up in 10.2% of the cases. Two patients (0.8%) were lost to follow-up. Of the 254 cases with follow-up, 62.6% were benign and 37.4% were malignant. The benign to malignant ratios were 1:1 and 2:1 in the screening and symptomatic groups, respectively. The atypical category in the screening population mostly yielded fat necrosis, complex sclerosing lesions and low- to intermediate-grade carcinoma on follow-up. The main outcomes in the symptomatic group were papilloma, fibroadenoma, ductal carcinoma in situ and lobular carcinoma. Preanalytical (suboptimal samples) factors were encountered in 34.8% and interpretative factors in 65.2% of the cases. Uncertainty about cellular morphology was attributed to such a diagnosis in 38 (14.8%) of the cases, architectural complexity in 137 (53.5%) and morphology and architecture in 70 (27.3%); 4.3% of cases were considered nondiagnostic. Conclusion: The atypical category is a necessary diagnosis but of limited use from a patient management perspective. Some preanalytical factors such as poor sample quality can be minimized by the involvement of cytopathologists in the FNA procedure. The use of the atypical category is partly dependent on the experience and confidence of the reporting pathologist. Assigning a case to this category is also likely to be unduly influenced by clinical or radiological findings. Our study indicates that the use of the atypical category can be reduced by up to 40% by appreciating these contributing factors. The practical utilization of the atypical category in breast cytology remains subjective and further study is required to identify useful objective criteria.

Background: Fine-needle aspiration (FNA) of difficult breast lesions often results in an atypical (C3) report. The assortment of outcomes generated by C3 reports varies widely, and this has given rise to different clinical management pathways. Objective: To identify and objectively assess microscopic features associated with atypical/C3 breast FNA cases. Materials and Methods: A total of 230 atypical breast FNAs were subjected to a blind microscopic rescreen using a range of robust qualitative and quantitative cytological criteria including cellularity, architectural qualities, cytomorphology and background features. A logistic regression with a receiver operating characteristic (ROC) curve and the resultant forward stepwise analysis were conducted to assess the results. This statistical testing was measured against malignant, benign proliferative and benign non-proliferative outcomes. Results: The malignant and benign proliferative outcomes showed a mixture of opposing protective and predictive individual cytological criteria. The stepwise analysis produced models demonstrating the best combination of individual cytological criteria for malignancy, proliferative and benign non-proliferative entities. In the malignancy model, discohesion, nuclear crowding within sheets, diminished numbers of bare bipolar nuclei and myoepithelial cells, the presence of tubules or necrosis and the absence of a cystic background were important features. The benign proliferative model suggested the same criteria but with the opposite implication and with the addition of several others, such as the presence of apocrine metaplasia, retained polarity and a speckled or coarse chromatin pattern. Age was a significant factor in malignant and proliferative outcomes. The benign non-proliferative stepwise analysis produced a model with fewer criteria (complex sheets, bare bipolar nuclei and a cystic background) limiting clinical application. Conclusion: Atypical/C3 breast cytology remains a legitimate reporting category. However, it is associated with a number of different histological outcomes. The incidence of the C3 category can be significantly reduced by controlling extrinsic factors and understanding the associated microscopic features.

Objectives: To identify features that could define papillary ductal cell proliferation within the C3 category and to subcategorise papillary lesions into benign papillomas which can be managed conservatively and atypical/malignant papillary neoplasms which require surgical intervention. Study Design: A blind microscopic rescreen of all C3 cases was conducted. The corresponding histological outcome was compared with the cytology. Statistical analysis was performed using papillary versus non-papillary outcomes and benign versus atypical/malignant papillary lesions. In addition, macropapillary lesions (papilloma and encysted papillary carcinoma) were plotted against micropapillary ductal carcinoma in situ. Results: Two hundred thirty FNA cases reported as C3 included 72 papillary neoplasms (52 benign papillomas and 20 atypical/malignant papillary lesions). Features specific to papillary lesions within C3 include macropapillary fragments, complex sheets, palisading strips, cystic background, cohesion and a decreased nuclear-to-cytoplasmic ratio. Features favouring atypical/malignant papillary lesions include decreased numbers of bare bipolar nuclei, discohesion and a non-cystic background. These features are common to most breast malignancies; however, identification of papillary features often results in a downgraded diagnosis from C5. Conclusions: This study supports the ability to reliably identify papillary ductal cell proliferation within C3. Certain features can distinguish papillary lesions from other C3 pathologies. This separation is likely to be clinically useful as papillary lesions may require a different management approach.