Orbital TFE3-Rearranged Perivascular Epithelioid Cell Tumor: A Case Report and Review of the Literature

ABSTRACT

Perivascular epithelioid cell tumors (PEComas) are infrequent mesenchymal neoplasms that have particular histological and immunohistochemical features. Only a few cases have been described in the eye and orbit. This report presents a 28-year-old man who consulted for a painless left orbital mass. With the presumptive diagnosis of cavernous hemangioma, a surgical excisional biopsy was performed. Histopathological examination showed a well-delimited tumor composed of epithelioid cells with an eosinophilic cytoplasm and oval nucleus. The tumor cells stained diffusely for HMB-45 and transcription factor E3 (TFE3) and were focally positive for actin. There was no reactivity to S100 or desmin. Genetic testing revealed a TFE3 rearrangement. Based on these results, an extremely rare orbital TFE3-rearranged PEComa was diagnosed. Although no recurrence was seen at last follow-up, a review of the literature shows experience is limited regarding orbital PEComas and their malignant potential. Further research is needed to establish management guidelines, their association with the tuberous sclerosis complex, and the role of genetic mutations such as TFE3 rearrangement.

An international 3-center training and reading study to assess basal cell carcinoma surgical margins with ex vivo fluorescence confocal microscopy

BACKGROUND

Novel solutions are needed for expediting margin assessment to guide basal cell carcinoma (BCC) surgeries. Ex vivo fluorescence confocal microscopy (FCM) is starting to be used in freshly excised surgical specimens to examine BCC margins in real time. Training and educational process are needed for this novel technology to be implemented into clinic.

OBJECTIVE

To test a training and reading process, and measure diagnostic accuracy of clinicians with varying expertise level in reading ex vivo FCM images.

METHODS

An international three-center study was designed for training and reading to assess BCC surgical margins and residual subtypes. Each center included a lead dermatologic/Mohs surgeon (clinical developer of FCM) and three additional readers (dermatologist, dermatopathologist, dermatologic/Mohs surgeon), who use confocal in clinical practice. Testing was conducted on 30 samples.

RESULTS

Overall, the readers achieved 90% average sensitivity, 78% average specificity in detecting residual BCC margins, showing high and consistent diagnostic reading accuracy. Those with expertise in dermatologic surgery and dermatopathology showed the strongest potential for learning to assess FCM images.

LIMITATIONS

Small dataset, variability in mosaic quality between centers.

CONCLUSION

Suggested process is feasible and effective. This process is proposed for wider implementation to facilitate wider adoption of FCM to potentially expedite BCC margin assessment to guide surgery in real time.

Ex vivo confocal microscopy: revolution in fast pathology in dermatology

Confocal microscopy with in vivo and ex vivo modalities has been used in the evaluation of skin cancer and other dermatological disorders. Recent developments in ex vivo confocal microscopy allow for faster pathology assessment with greater accuracy by the visualization of cellular and architectural details, similarly to standard pathology, in either paraffin-embedded or frozen samples. They include the possibility of multimodal confocal microscopy using different lasers and fusion images. New staining protocols including immunostaining, with no damage to conventional histopathology preparation, have been recently described in melanocytic tumours and inflammatory skin diseases. Digital staining with haematoxylin and eosin is also incorporated in the new devices. In this review the applications of ex vivo confocal microscopy will be presented with the description of the technique and the technology, clinical evidence in dermatology and other fields, and further applications.

Factors associated with sentinel lymph node status and prognostic role of completion lymph node dissection for thick melanoma

INTRODUCTION

Sentinel lymph node (SLN) biopsy is useful for the prognostic stratification of patients with thick melanoma. Identifying which variables are associated with SLN involvement and establishing risk in different subgroups of patients could be useful for guiding the indication of SLN biopsy. The value of complete lymph node dissection (CLND) in patients with a positive SLN biopsy is currently under debate.

MATERIALS AND METHODS

To identify factors associated with SLN involvement in thick melanoma we performed a multicentric retrospective cohort study involving 660 patients with thick melanoma who had undergone SLN biopsy. To analyze the role of CLND in thick melanoma patients with a positive SLN biopsy, we built a multivariate Cox proportional hazards model for melanoma-specific survival (MSS) and disease-free survival (DFS) and compared 217 patients who had undergone CLND with 44 who had not.

RESULTS

The logistic regression analysis showed that age, histologic subtype, ulceration, microscopic satellitosis, and lymphovascular invasion were associated with nodal disease. The CHAID (Chi-squared Automatic Interaction Detection) decision tree showed ulceration to be the most important predictor of lymphatic involvement. For nonulcerated melanomas, the histologic subtype lentigo maligna melanoma was associated with a low rate of SLN involvement (4.3%). No significant differences were observed for DFS and MSS between the CLND performed and not-performed groups. Nodal status on CLND was associated with differences in DFS and MSS rates.

CONCLUSION

We identified subgroups of thick melanoma patients with a low likelihood of SLN involvement. CLND does not offer survival benefit, but provides prognostic information.

New treatments for human papillomavirus infection

Human papillomavirus infection is very common. In this article, we review the latest developments in the treatment of lesions caused by this virus, with a particular focus on anogenital warts. Sinecatechins and new imiquimod formulations are among the most significant new developments. Others include photodynamic therapy and intralesional immunotherapy, but there is insufficient evidence to recommend their routine use. Finally, while therapeutic vaccines and inhibitory molecules appear to hold great promise, they are still in the early phases of investigation. More studies are needed, and these should have similar designs, larger samples, and sufficiently long follow-up periods to enable the direct comparison of the short-term and long-term effectiveness of different treatment options.