Cutaneous clear cell/signet-ring cell squamous cell carcinoma arising in the right thigh of a patient with type 2 diabetes: combined morphologic, immunohistochemical, and etiologic analysis

Case Report: Optimum excision with split skin graft closure in the management of penile sebaceous carcinoma

Sebaceous carcinoma (SC) is a rare malignant skin neoplasm derived from the meibomian gland of adnexal epithelium, which is frequently confused with basal cell carcinoma (BCC), exhibiting sebaceous differentiation and commonly found in the head and neck regions. We report a case of penile sebaceous carcinoma, an extremely rare anatomical site for SC. A 68-year-old man presented with a 4-month history of painless, non-healing ulcerated nodules over the left side of the penile shaft. Wedge biopsy showed adenocarcinoma with signet ring differentiation. We proceeded with wide local excision (WLE) of the lesion with the inclusion of the indurated skin and 5 mm of normal margin, followed by primary closure of the scrotal defect and split skin grafting of the penile shaft by using a thigh skin donor. The final histopathological examination revealed sebaceous carcinoma with pagetoid spread. The patient achieved recurrence-free survival without any form of adjuvant therapy after 4 years of follow-up.

Signet-Ring Cell Squamous Cell Carcinoma: A Biphenotypic Neoplasm of the Gastro-Esophageal Junction with Uncertain Biological Potential: Case Report and Literature Review

The signet-ring cell variant of squamous cell carcinoma (SCC) is an extremely rare histological subtype, with only 24 cases (including the present case) reported in the Medline database: 15 affecting the external surface of the body, 3 in the lung, 2 affecting the uterine cervix, 1 involving the gingiva, another one affecting the esophagus and the present case that is the first reported at the gastro-esophageal junction (GEJ). In one case, the location of the lesion was not mentioned. A 59-year-old male patient underwent segmental eso-gastrectomy for carcinoma of the GEJ. The microscopic examination showed a pT3N1-staged SCC composed of solid nests admixed in over 30% of the tumor, with cells having eccentrically located nuclei and clear vacuolated cytoplasm. The signet-ring cells did not show mucinous secretion and were positive for keratin 5/6 and vimentin, with nuclear expression of β-catenin and Sox2 and focal membrane positivity for E-cadherin. Based on these features, the case was considered a signet-ring SCC with epithelial-mesenchymal transition. Thirty-one months after surgery, the patient was disease-free, with no local recurrence and no known distant metastases. In SCC, a signet-ring cell component might be an indicator of the dedifferentiation of tumor cells towards a mesenchymal molecular subtype.

Cutaneous Squamous Cell Carcinoma with Signet-Ring Cell Component and CDX2 Expression in a Patient Treated with PD-1 Inhibitor: A Case Report of a Common Tumor with Unusual Differentiation

Signet-ring cell squamous cell carcinoma (SRCSCC) is an uncommon variant of cutaneous SCC that has been reported in the head and neck region. Herein, we present a case of a 56-year-old female with a cutaneous SCC that recurred after surgical excision, during treatment with cemiplimab (a programmed death receptor-1 (PD-1) inhibitor). Histologically, the recurrent SCC revealed a second component characterized by the presence of signet-ring-like cells (SRLCs). Immunohistochemical studies demonstrated that the tumor cells were positive for P63, CK5/6, CDX2, and P53 while negative for P16, CK7, CK20, and CD68 stains. An abnormal expression of B-catenin was also observed in the tumor. To our knowledge, SRCSCC developing during treatment with an immune checkpoint inhibitor has not been documented in the literature. Our findings suggest a form of acquired SCC cell resistance to immunotherapy that might involve CDX2-related pathways.

A previously undescribed variant of cutaneous clear-cell squamous cell carcinoma with psammomatous calcification and intratumoral giant cell granulomas

Cutaneous clear-cell squamous cell carcinoma (ccSCC) is a rare variant of SCC composed of clear cells that lack cytoplasmic glycogen or evidence of tricholemmal keratinization. We report a previously undescribed variant of ccSCC with psammomatous calcification and intratumoral giant cell granulomas. The differential diagnosis with trichilemmal carcinoma is outlined according to the criteria of the fourth edition of World Health Organization (WHO) classification. Our findings outline that psammomatous calcification may occur inside the keratinous pearls of the neoplastic lobules triggering an intratumoral giant cell granulomatous reaction. The prognostic significance of this histopathological presentation is unknown but the potential for formation of psammoma bodies in cSCC should be considered to avoid diagnostic pitfalls.

Cutaneous signet-ring cell squamous cell carcinoma

Cutaneous signet-ring cell squamous cell carcinoma (SRCSCC) is a rare variant, most commonly occurring in the head and neck. We report a case of a 66-year-old transgender woman with an ulcerated growing facial mass measuring 5.6 × 4.0 × 2.0 cm. Histological analysis showed features consistent with SRCSCC. Immunohistochemical analysis showed positive staining for high-molecular-weight cytokeratin, estrogen receptor (1-2+ in 10%), E-cadherin (mostly positive with partial loss), and p40 and negative staining for Ber EP-4, cytokeratin 7, low-molecular-weight cytokeratin, mucicarmine, Alcian blue PAS, HER2, and MUC4. The tumor had invaded the perineurium, lymphovascular spaces, and subcutaneum. Additionally, microsatellite instability testing was negative. This case adds to the limited knowledge of this poorly characterized entity.

Split thickness skin graft in active psoriasis in patient with clear cell variant squamous cell carcinoma

The case report discusses split thickness skin grafting in a patient with active psoriasis. This also reports a case of a rare variant of squamous cell carcinoma.

MR Imaging of Mushroom-like Skin Adnexal Tumors in the Scalp: A Report of Two Cases

Few studies had been published regarding imaging findings of skin adnexal tumors. We experienced two giant cases of them with a characteristic mushroom-like growth pattern. MRI showed a circumscribed mushroom-like shaped mass extruding from the subcutaneous tissue with microcystic lesions. Although differentiation between benignancy and malignancy may be difficult by radiological examinations, MRI may be helpful to identify its origin and differentiate soft tissue tumors with skin adnexal tumors in having these imaging findings.

Primary Cutaneous Follicle Center Lymphoma Clear Cell Variant: Expanding the Spectrum of Cutaneous Clear Cell Neoplasms

Primary cutaneous follicle center lymphoma is the most frequent cutaneous B-cell lymphoma despite the fact that is an uncommon disease. Mild biological behavior and good prognosis characterized this neoplasm with a low aggressiveness compared with classic nodal follicular lymphoma (FL). Rare histological variants have been described. We present the case of a 72-year-old man who underwent surgery for a cutaneous nodule on his left scapula. The biopsy showed a dermal clear cell proliferation arranged in a nodular and diffuse pattern. The cells stained positive for CD20 and Bcl-6 supporting B-cell follicular differentiation. The final diagnosis was "primary cutaneous follicle center lymphoma" with "clear cell changes" according to the 2016 World Health Organization classification of lymphoid neoplasms. Additional tests to rule out a systemic involvement were performed. The prognosis was favorable with a disease-free survival of 7 years after complete surgical excision. It has been assumed that cutaneous tumors composed of clear cells may have an epithelial, melanocytic, adnexal, mesenchymal, or metastatic origin. The correct histopathological diagnosis required immunohistochemistry and even molecular techniques. To the best of our knowledge, this is the first report of a cutaneous clear cell lymphoma and of a FL with clear cell features. Our findings provide evidence that the heterogeneity of FL is greater than previously thought and expand the spectrum of differential diagnosis in cutaneous clear cell neoplasms. Dermatopathologists should be aware of this entity and should comprise a PanB marker in their first- or second-line immunohistochemistry for the correct diagnosis of a dermal clear cell proliferation.

Mushroom-Like Skin Tumours: Report of Three Cases

Mushroom like the growth of skin tumour is a rare phenomenon although described already in 1806 by Alibert, who focused on mycosis fungicides. We identified only four case reports in PUBMED database using the terms “mushroom-like growth” and “skin tumour”. We analysed our files and identified three elderly female patients (69 to 94 years old). Histological diagnosis was melanoma, Merkel cell carcinoma and basal cell carcinoma. All tumours could be completely removed by wide excision or delayed Mohs surgery. No metastatic spread was noted.