Tekin, Burak

AbstractBackgroundThere is a dearth of studies investigating the efficacy of hydroxychloroquine in the treatment of either anogenital lichen sclerosus or extragenital lichen sclerosus, a condition that, if left untreated, could lead to a greater degree of scarring and malignant transformation.ObjectiveThis study aims to analyze the demographic characteristics, clinicopathological features, treatment response, and outcomes of patients diagnosed with either anogenital or extragenital lichen sclerosus who received hydroxychloroquine therapy.MethodsA retrospective analysis was conducted involving 70 patients diagnosed with lichen sclerosus who underwent treatment with hydroxychloroquine at our institution between 2018 and 2023.ResultsAmong the cohort, 67 patients were female, and 3 were male. Extragenital lichen sclerosus was diagnosed in 23 patients, with 16 exhibiting concomitant morphea overlap. Itching was the predominant clinical presentation (67%). A notable proportion of patients (36%) had a connective tissue disorder, prompting hydroxychloroquine therapy. Among the 30 patients treated solely for lichen sclerosus, 21 demonstrated response and 9 had no response. From a broader comparison of response to hydroxychloroquine, the overall anogenital response rate was 84.6% as opposed to 50% in extragenital lichen sclerosus. The median time to initial response was 4 months. Adverse effects, predominantly mild, were observed in 10 (14.3%) patients.LimitationThis study is constrained by its retrospective nature and reliance on data from a single center, resulting in a limited sample size.ConclusionHydroxychloroquine demonstrates promise as a therapeutic option for anogenital lichen sclerosus because of its favorable response rates and low incidence of adverse effects. However, further investigations, including larger‐scale or prospective studies, are imperative to ascertain its definitive efficacy.

Abstract: Paratesticular mesothelioma (malignant mesothelioma arising from the tunica vaginalis of the testis) represents a small proportion of mesothelial neoplasms, and cutaneous involvement by paratesticular mesothelioma is very rare. Cutaneous involvement can manifest as scrotal subcutaneous nodules from regional spread, distant metastasis, or direct extension through surgical scars. Mesothelioma has 3 histopathologic classifications that include epithelioid, biphasic, and sarcomatoid, which is rarely seen in paratesticular mesothelioma. Given the rarity of this condition, cutaneous mesothelioma may be misdiagnosed as histologic mimics, such as metastatic adenocarcinoma or adnexal neoplasms; thus, appropriate immunohistochemical workup and clinical correlation are required to make an accurate diagnosis. In this case, a 75-year-old man with a history of paratesticular mesothelioma, status postorchiectomy, presented with right-sided scrotal swelling, erythema, and subcutaneous nodules. These nodules were identified as local recurrence with cutaneous involvement by paratesticular mesothelioma on histopathologic examination. This case highlights the clinical and histopathologic features of this diagnosis and underscores the importance of dermatopathologists being aware of this condition to ensure accurate diagnosis.

TPS5108 Background: Penile cancer is a devastating malignancy that affects just over 2000 patients per year in the United States and approximately 40,000 worldwide. Metastatic or unresectable penile cancer is rapidly fatal in most cases and there are few effective systemic therapy options.1 There is an urgent need for alternatives to chemotherapy such as immunotherapy or targeted therapy. Enfortumab vedotin (EV) is an antibody-drug conjugate targeting nectin-4 protein on the tumor cell surface and having efficacy in treatment of metastatic urothelial carcinoma.2 Recent studies have demonstrated frequent and strong expression of nectin-4 in penile squamous cell carcinoma (PSCC).3,4 In this setting, Mayo Clinic is leading a phase II trial of EV for advanced PSCC, currently in progress. Methods: This single arm, open-label, two-stage, phase II trial evaluates best overall response rate (BRR) to EV in patients with PSCC regional lymph node involvement or distant metastatic (M1) disease. Participants may have had any prior systemic therapy or be treatment naïve. Previously untreated patients must be ineligible for or have refused surgery or radiotherapy, have N2-N3 disease and are ineligible for or have refused neoadjuvant chemotherapy, or have clinical evidence of M1 disease. Participants will receive treatment with EV until disease progression, withdrawal, death, or limiting toxicity. Participants will receive EV 1.25 mg/kg intravenous on days 1, 8, and 15 of a 28-day cycle, with tumor assessment performed at 8-week intervals. The primary endpoint is the combined BRR of partial and complete responses (whether confirmed or unconfirmed) according to RECIST 1.1. Secondary endpoints are confirmed response rate, duration of response, progression-free survival, overall survival, adverse events, and BRR in HPV related and unrelated subgroups. Stage 1 will consist of 15 participants, and if there are 2 or more responses will proceed to Stage 2 with an additional 10 participants. The trial opened to enrollment in December 2023, and is active at Mayo Clinic sites in Minnesota, Arizona, and Florida. Clinical trial information: Funding and drug supplied by Astellas Pharma Global Development, Inc./Seagen Inc. NCT06104618. 1. Chahoud J, et al., Curr Opin Urol. 2022 Jan 1;32(1):8-16. 2. Powles T, et al. N Engl J Med. 2021 Mar 25;384(12):1125-1135. 3. Tekin B, et al. Hum Pathol. 2023 Dec;142:42-50. 4. Grass GD, et al. Eur Urol Open Sci. 2023 Jan 10;49:1-5. Clinical trial information: NCT06104618 .

Discovery of effective systemic therapies for patients with advanced penile cancer has been slow to occur. Comprehensive genomic profiling from several studies shed light on the molecular oncogenesis of penile squamous cell carcinoma (PSCC) and differences between HPV-related and unrelated tumors. While these two subsets of PSCC appear distinct in their biology, there are not yet specific treatment strategies recommended on that basis. Cell surface proteins have been identified that may potentially serve as drug targets for monoclonal antibodies or small molecule inhibitors. Here, we review some of the new biological insights regarding PSCC that could lead to improved therapies, as well as the related clinical trials recently completed or in progress. We conclude that antibody-drug conjugates are especially promising, as are the combinations of immune checkpoint inhibitors with other types of drugs.

Molecular investigations have led to increased therapeutic options for prostatic adenocarcinoma. A single case report of a PRPSAP1 :: NTRK3 gene fusion occurring in prostate cancer was previously reported. A review of the literature revealed that NTRK gene rearrangements are exceedingly rare molecular events in prostate cancer. NTRK gene fusions can be oncogenic drivers or develop as resistance mechanisms. The tumor-agnostic approvals of TRK inhibitors by the FDA provide additional rationale for molecular investigations of aggressive prostatic adenocarcinomas. This may prove to be an additional therapeutic option for patients with aggressive prostatic carcinomas refractory to initial therapy. We report a case of an aggressive castrate-resistant prostatic adenocarcinoma with a BMP6 :: NTRK3 gene fusion.

Background: Cutaneous malignant mixed tumor (MMT) is a rare sweat gland–derived tumor characterized by admixed malignant epithelial cells and chondromyxoid stroma. Approximately 50 cases have been described in the literature. Metastasis, which may occur in more than one-third of cases, is most common in the lung. Methods: We summarized the clinicopathologic features of a patient with cutaneous MMT metastatic to the lungs. A literature review of similar cases was completed using Web of Science, Scopus, and PubMed databases. Results: A woman in her 70s presented with an enlarging mass on her left eyebrow; histopathologic examination showed large islands of atypical cells with increased mitotic activity, admixed with necrosis on a background of fibrotic and chondromyxoid stroma. Multiple lung nodules were identified during follow-up. Examination of a pulmonary core needle biopsy specimen was consistent with metastatic cutaneous MMT. Literature review identified 10 cases published between 1980 and 2017. Most primary tumors were large (≥4 cm). Local recurrence was uncommon, and the lung was the only metastatic site in 5 cases. Histopathologically, metastatic tumors were described as more cellular, with diminished stromal tissue compared with the primary lesion. Conclusion: This is 1 of the 11 reports of cutaneous MMT with metastasis to the lungs found in the English-language literature published after 1980. Of note, most reports were published before 1990, making this case study one of the few contemporary descriptions of cutaneous MMT with pulmonary metastases. We think that the present case report will increase the awareness of this rare tumor.

Abstract Objectives There is a paucity of data on penile amyloidosis. We aimed to assess the frequency of different amyloid types in surgical specimens from the penis involved by amyloidosis and correlate relevant clinicopathologic parameters with proteomic findings. Methods Since 2008, our reference laboratory has performed liquid chromatography/tandem mass spectrometry (LC-MS/MS) for amyloid typing. The institutional pathology archive and reference laboratory database were queried to retrospectively identify all penile surgical pathology specimens with LC-MS/MS results between January 1, 2008, and November 23, 2022. Archived H&E-stained and Congo red–stained sections were re-reviewed. Results Twelve cases of penile amyloidosis were identified, which represented 0.35% (n = 3,456) of penile surgical specimens. AL-type amyloid was most frequent (n = 7), followed by keratin-type amyloid (n = 3) and ATTR (transthyretin)–type amyloid (n = 2). AL-type amyloid cases often showed diffuse dermal/lamina propria deposition, whereas all keratin-type amyloid cases were localized to the superficial dermis. Two cases with keratin-type amyloid had concomitant cutaneous findings (penile intraepithelial neoplasia and condyloma). Conclusions This series, the largest to date, demonstrates that penile amyloidosis has a heterogeneous proteomic landscape. To the best of our knowledge, this is the first study describing ATTR (transthyretin)–type penile amyloid.