BACKGROUND: A subset of patients affected by cutaneous squamous cell carcinoma (cSCC) can exhibit locally invasive or metastatic tumors. Different staging classification systems are currently in use for cSCC. However, precise patient risk stratification has yet to be reached in clinical practice. The study aims to identify specific histological and molecular parameters characterizing metastatic cSCC.
METHODS: Patients affected by metastatic and non-metastatic cSCC (controls) were included in the present study and matched for clinical and histological characteristics. Skin samples from primary tumors were revised for several histological parameters and also underwent gene expression profiling with a commercially available panel testing 770 different genes.
RESULTS: In total, 48 subjects were enrolled in the study (24 cases, 24 controls); 67 genes were found to be differentially expressed between metastatic and non-metastatic cSCC. Most such genes were involved in immune regulation, skin integrity, angiogenesis, cell migration and proliferation.
CONCLUSIONS: The combination of histological and molecular profiles of cSCCs allows the identification of features specific to metastatic cSCC, with potential implications for more precise patient risk stratification.

Lymphoepithelioma-like carcinoma of the skin (LELCS) is a rare primary skin cancer, with an annual incidence of 1/100,000 and about 85 cases published in the literature. It is considered the cutaneous counterpart of undifferentiated nasopharyngeal carcinoma (UNC, Schmincke-Regaud tumor) but has no association with EBV. We present an interesting case with features of LELCS in a 93-year-old man, right frontal-orbital region, diagnosed histologically and with immunohistochemical features. We also emphasize contrasting morphologic features for correct nosographic classification and address current issues, suggesting potential insights. Finally, we briefly reviewed other cases described in the literature.

Squamous differentiation of prostate cancer, which accounts for less than 1% of all cases, is typically associated with androgen deprivation treatment (ADT) or radiotherapy. This entity is aggressive and exhibits poor prognosis due to limited response to traditional treatment. However, the underlying molecular mechanisms and etiology are not fully understood. Previous findings suggest that squamous cell differentiation may potentially arise from prostate adenocarcinoma (AC), but further validation is required to confirm this hypothesis. This paper presents a case of advanced prostate cancer with a combined histologic pattern, including keratinizing SCC and AC. The study utilized whole-exome sequencing (WES) data to analyze both subtypes and identified a significant overlap in driver gene mutations between them. This suggests that the two components shared a common origin of clones. These findings emphasize the importance of personalized clinical management for prostate SCC, and specific molecular findings can help optimize treatment strategies.

Breast implant capsule-associated squamous cell carcinoma is exceedingly rare, with only eleven previously published cases. The present study systematically reviews the current literature and describes an additional case in a 56-year-old patient who had undergone previous breast implant augmentation with textured silicone implants 22 years prior. Systematic review of the literature demonstrated a scarcity of reported cases, yielding only eleven other incidences. Symptomatology for this patient involved pain, swelling, and erythema of the right breast prior to eventual surgery. Magnetic resonance imaging reporting extensive oedema and a large periprosthetic effusion with lobulated changes. The patient proceeded with bilateral capsulectomies and histology demonstrated moderately differentiated squamous cell carcinoma, areas of squamous metaplasia, and a chronic inflammatory cell infiltrate. Postoperatively, a positron-emission tomography scan showed no concerning uptake of fluorodeoxyglucose and no evidence of metastatic disease. The patient proceeded to a right-sided total mastectomy and axillary lymph node biopsy. Final histology demonstrated remnant well-differentiated squamous cell carcinoma, whilst five lymph nodes were negative of disease. The patient received postoperative radiation therapy. A clinical history of swelling and pain appears to be a common presentation for this condition. Aspirations of periprosthetic collections containing squamous cells should be considered concerning for neoplasm. The presence of squamous metaplasia within the specimen provides some credence for transformation to invasive carcinoma mediated through chronic inflammation. The presence of perineural invasion would be worth reporting in future cases as it may confer similar risk characteristics as in cutaneous squamous cell carcinoma. A finding of remnant carcinoma during completion mastectomy provides support for an aggressive approach to surgical resection. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

BACKGROUND: To describe a case of orbital spindle cell carcinoma which presented with limbal ischemia and briefly review the literature.
METHODS: Retrospective case report and brief literature review.
RESULTS: A 61-year old man presented with blepharoptosis, periorbital pain, decreased vision and limbal ischemia. He did not mention any previous illness and did not take any kind of drugs. Imaging revealed an orbital mass that was positive for SMA, Vimentin and CD99 and negative for S100. We treated the patient with chemotherapy and followed him for other complications that occurred throughout disease course.
CONCLUSIONS: Spindle cell carcinomas are a rare variant of squamous cell carcinoma (SCC) with dual malignant histologic differentiation of squamous and mesenchymal cells. Few cases of orbital spindle cell carcinoma have been reported, which have been either secondary to distant metastasis or regional spread. In this study, we have reported the first case of primary orbital spindle cell carcinoma presenting with limbal ischemia. Further studies are needed to describe the different clinical presentations and management strategies of this rare clinical entity.

Percutaneous endoscopic gastrostomy tubes are often placed in patients with head and neck malignancy for long-term nutritional support. Though rare, head and neck squamous cell carcinoma can metastasize to the percutaneous endoscopic gastrostomy tube site and may initially present as a developing mass or as bleeding at the percutaneous endoscopic gastrostomy site. Patients with head and neck squamous cell carcinoma should be evaluated diligently before and after percutaneous endoscopic gastrostomy placement in order to avoid this rare but life-threatening complication. We present a case of tongue squamous cell carcinoma that metastasized to the percutaneous endoscopic gastrostomy tube site causing gastrointestinal bleeding.

Synchronous tumors of the rectum and anus are sporadic. Most cases in the literature are rectal adenocarcinomas with concomitant anal squamous cell carcinoma. To date, only two cases of concomitant squamous cell carcinomas of the rectum and anus are reported, and both were treated with up-front surgery and received abdominoperineal resection with colostomy. Here, we report the first case in the literature of a patient with synchronous HPV-positive squamous cell carcinoma of the rectum and anus treated with definitive chemoradiotherapy with curative intent. The clinical-radiological evaluation demonstrated complete tumor regression. After 2 years of follow-up, no evidence of recurrence was observed.

Tailgut cyst, a type of retro-rectal cyst, is a rare condition requiring evaluation for malignant transformation. We report a case of squamous cell carcinoma arising in the retro-rectal cyst, in a 51-year-old female who underwent incomplete resection of the cyst and chemo-radiotherapy, subsequently became locally recurred and metastatic.

This case reports a rare case of conjunctival squamous cell carcinoma in China. The elderly (86-year-old) female patient was diagnosed and treated effectively after three times of diagnosis. During this period, she was misdiagnosed and ineffective treatment for many times. Therefore, we propose to make an integrated diagnosis based on histopathological diagnosis, combined with a variety of diagnostic methods including MRI and CDFI, supplemented by updated multiple immunohistochemically techniques, so as to achieve the purpose of accurate diagnosis.

Voriconazole is an antifungal with known side effects of phototoxicity and photocarcinogenesis. We present a case of HPV-related multifocal squamous cell carcinoma in a 68-year-old man with HIV, due to accelerated photocarcinogenesis associated with long-term use of voriconazole. Histology confirmed SCC with HPV-related features and he was found to have metastases. Multifocal SCC is unusual in association with voriconazole and HIV infection and only one other case has been reported. It is important for clinicians to be aware of the photocarcinogenic effects of voriconazole, especially in patients with HIV.