Comparison of Primary and Metastatic Fumarate Hydratase-Deficient Renal Cell Carcinomas Documents Morphologic Divergence and Potential Diagnostic Pitfall With Peritoneal Mesothelioma.

Fumarate hydratase (FH)-deficient renal cell carcinomas are rare neoplasms characterized by wide morphologic heterogeneity and pathogenetic mutations in the FH gene. They often show aggressive behavior with rapid diffusion to distant organs, so novel therapeutic scenarios have been explored, including EGFR inhibitors and PD-L1 expression for targeted immunotherapy. Herein, we investigated a series of 11 primary FH-deficient renal cell carcinomas and 7 distant metastases to evaluate tumor heterogeneity even in metastatic sites and estimate the specific spread rates to various organs. Furthermore, the tumors were tested for immunohistochemical PD-L1 expression and EGFR mutations. Most metastatic cases involved the abdominal lymph nodes (4/7; 57%), followed by the peritoneum (3/7; 42%), the liver (2/7; 29%), and the lungs (1/7; 14%). Six metastatic localizations were histologically documented, revealing a morphologic heterogeneous architecture often differing from that of the corresponding primary renal tumor. Peritoneal involvement morphologically resembled a benign reactive mesothelial process or primary peritoneal mesothelioma, thus advocating to perform an accurate immunohistochemical panel, including PAX8 and FH, to reach a proper diagnosis. A pure low-grade succinate dehydrogenase-looking primary FH-deficient renal cell carcinoma was also recorded. As for therapy, significant PD-L1 labeling was found in 60% of primary renal tumors, whereas none of them carried pathogenetic EGFR mutations. Our data show that FH-deficient renal cell carcinoma may be morphologically heterogeneous in metastases as well, which involve the lymph nodes, the liver, and the peritoneum more frequently than other renal tumors. Due to the high frequency of this latter (42%), pathologists should always be concerned about ruling out mesothelial-derived mimickers, and the occurrence of rarer, primary, low-grade-looking types. Finally, contrary to EGFR mutations, PD-L1 expression could be a possible predictive biomarker for the therapy of these tumors.

Head and neck melanoma: the eyelid region has a better prognosis and easier management: a retrospective survey and systematic review.

Eyelid melanoma (EM) is a malignant neoplasm accounting for around 1% of eyelid malignancies. Because of its rarity, most of our knowledge of EM is currently based on studies of cutaneous melanomas located elsewhere. Accordingly, this study aimed to specifically evaluate EM characteristics, management strategies, and prognosis. A retrospective study was carried out on patients diagnosed with EM at Careggi University Hospital, Florence between May 2012 and May 2022. In addition, a systematic review of relevant literature was conducted, encompassing studies published from 2013 to 2023. Clinical, histopathological, therapeutical, and prognostic data were analyzed to assess the metastasis rate and the 5-year survival rate of patients with EM. Separate data were extracted for in situ and invasive disease. Our original study included 19 patients diagnosed with EM with a 5-year survival rate of 100% for in situ and 83.3% for invasive EM. The literature review identified five poorly detailed large database reviews and 14 original studies on EM with an overall 5-year survival rate of 79.7%. The present research indicates that EM is a challenging malignancy, but has a relatively better prognosis and easier management than other melanomas of the head and neck region. These are probably related to the anatomical location which leads to early diagnosis. Therefore, EM should be considered as a specific disease requiring dedicated treatment. Based on the personal authors' experience and comprehensive overview of the current knowledge, a dedicated protocol is proposed.

Dermoscopy as a Tool for Identifying Potentially Metastatic Thin Melanoma: A Clinical-Dermoscopic and Histopathological Case-Control Study.

Despite being early-stage tumors, thin cutaneous melanomas contribute significantly to mortality and have a rising incidence. A retrospective case-control study was performed to identify clinical-dermoscopic and histopathological variables linked to local and distant metastases in melanomas ≤0.8 mm. Data from 1 January 2000 to 22 June 2022 were analyzed from two Italian skin cancer referral centers. Sixteen patients with ≤0.8 mm melanomas developing metastases were studied compared to controls without metastases over 5 years. Statistical analysis involved Pearson's chi-squared test or Fisher's exact test. Of the 1396 cases, 1.1% progressed. The median diagnosis age was 49 (range 28-83), with 56.3% men and 43.7% women. The torso was the primary tumor site (43.7%). Clinically, lesions were pigmented (>10 mm diameter: 73.3%, ≥3 colors: 80%). Dermoscopically, the common features were white patches (73.3%), atypical vascular patterns (66.5%), blue-gray areas (60%) and absent pigment networks (60%). Histopathologically, all cases had adverse features like regression (87.4%), dermal mitoses (50%), a vertical growth phase (62.5%) and ulceration (12.5%). These findings were statistically significant compared to controls (p < 0.05). In ≤0.8 mm melanomas, specific clinical-dermoscopic traits might indicate higher metastatic potential when paired with adverse histopathological features.