High tumour-infiltrating lymphocytes correlate with distinct gene expression profile and favourable survival in single hormone receptor-positive breast cancer.

Introduction: This study aimed to evaluate the impact of tumour-infiltrating lymphocytes (TILs) on the expression of immune-related genes and prognosis in single hormone receptor-positive breast cancer. Material and methods: Tumour-infiltrating lymphocytes were analysed according to the guidelines of the International TILs Working Group in a cohort of 206 patients with single hormone receptor-positive breast cancer. Of these, 44.7% were classified as ER+/PgR-/HER2-, 18.4% as ER+/PgR-/HER2+, 26.2% as ER-/PgR+/HER2-, and 10.7% as ER-/PgR+/HER2+. Moreover, in 52 samples the analysis of gene expression profiling was performed using nCounter technology. Results: Most cases (74.3%) showed at least 1% of stromal TILs, with a median of 4%, mean of 16.3%, and interquartile range of 0-20%. ER-/PgR+ tumours displayed significantly higher TILs density than ER+/PgR- cases (p < 0.001, Wilcoxon test), regardless of HER2 status. The abundance of TILs was positively associated with ER-/PgR+ phenotype, higher Ki-67, and higher grade, but not with age, tumour size, or regional and distant metastases at diagnosis. Additionally, in ER+/PgR- subgroup higher TILs were associated with HER2-positive status. Stromal TILs > 5% were associated with better survival in the whole group, but this effect was less prominent in ER-/PgR+ patients. We identified 50 differentially expressed genes (DEGs) between single hormone receptor-positive breast tumours with high and low TILs, including 39 up-regulated and 11 down-regulated genes in the high TILs group. Conclusions: The up-regulated expression of immune-related genes was consistent also among separately analysed single hormone receptor-positive groups (ER+/PgR- and ER-/PgR+).

Diagnostic test accuracy meta-analysis of PRAME in distinguishing primary cutaneous melanomas from benign melanocytic lesions.

PRAME is a novel immunohistochemical marker that aids the diagnosis of melanocytic lesions. Diffuse PRAME positivity suggests melanoma, whereas benign naevi are negative or only weakly positive. However, the factual diagnostic accuracy of PRAME is not well established. Moreover, some studies have suggested that the threshold of 3+/50% positive cells may be more useful in practice than the most widely used cut-off (4+/75% of positive cells). Hence, we performed a systematic review and diagnostic accuracy meta-analysis to evaluate sensitivity, specificity, likelihood ratios and optimal threshold for PRAME in distinguishing benign melanocytic proliferations from melanomas. Twenty-six studies were enrolled into the meta-analysis. A total of 2915 melanocytic lesions were analysed. The optimal threshold for PRAME positivity was estimated at 3.11, which translates into 3+ in practice. Sensitivity and specificity calculated from SROC at the 3+ threshold were 0.735 (0.631-0.818) and 0.915 (0.834-0.958), respectively, compared to 0.679 (0.559-0.957) and 0.957 (0.908-0.981) at the 4+ cut-off. In subgroup analysis, the spitzoid subgroup was characterised by the lowest sensitivity and diagnostic odds ratio of PRAME. Our findings indicate that PRAME immunohistochemistry may serve as an ancillary marker to support the diagnosis of melanoma. Nevertheless, the accuracy of PRAME may be lower in spitzoid neoplasms. Our meta-analysis suggests that the 3+/50% threshold might be more useful in practice than the 4+/75% cut-off, as it shows higher sensitivity with retained satisfactory specificity.

Great mimicker - a case of occult melanoma displaying ganglioneuroblastic differentiation.

Melanomas are known for their diverse morphological features, presenting a diagnostic challenge for pathologists. Uncommon variations of melanoma can exhibit distinct cytological and histomorphological characteristics, including ganglioneuroblastic differentiation. However, this phenomenon is extremely rare, with only a few documented cases. Here, we present a unique case of an occult metastatic melanoma with ganglioneuroblastic differentiation developing in a 76-year-old male. The diagnosis was based on histopathology, immunophenotyping, and molecular testing, which revealed SOX10 positivity and an NRAS mutation. Notably, classic melanoma markers HMB45 and melan-A were negative, highlighting the importance of considering alternative markers. This case emphasizes the significance of immunohistochemistry and molecular investigation in diagnosing melanomas with unusual features and identifying appropriate candidates for immune checkpoint therapy. Additionally, the occurrence of ganglioneuroblastic differentiation further supports a shared histogenetic origin from the neural crest. Improved understanding of such rare variants contributes to accurate diagnosis and optimal management of melanoma patients.

Testicular teratoma with nephroblastoma in an adult - case report and literature review.

Testicular germ cell tumours are the most common malignancies in young men. Germ cell tumours can be classified as seminomas or non-seminomas, each with different clinical features and treatment approaches. Germ cell tumours are occasionally associated with somatic-type malignancy, particularly in metastatic lymph nodes after adjuvant chemotherapy. Adenocarcinomas and rhabdomyosarcoma are the most common malignancies in this setting. In this report, we present a unique case of a 37-year-old patient who presented with a testicular teratoma containing a nephroblastoma component. The tumour exhibited characteristic morphology that resembled foetal kidney and expressed nuclear WT-1 and PAX-8 on immunohistochemistry. Following surgery, the patient opted for active surveillance and remains disease-free. To date, only 7 cases of nephroblastoma in primary testicular teratoma have been reported. This case highlights the importance of considering this rare entity in the differential diagnosis of testicular teratomas and the need for careful pathological examination.

Metastasis to the ureter as the first manifestation of occult pulmonary adenocarcinoma. Case report and review of the literature.

Lung cancer is a major epidemiological threat worldwide, which commonly metastasizes to distant sites. Often, the presence of metastasis is the first manifestation of lung cancer. Some of the most common sites for lung cancer metastasis are bones, adrenal glands, liver, brain, and lungs. However, metastases to unusual locations pose a diagnostic and therapeutic challenge. We present a case of a 74-year-old woman in whom the first manifestation of lung cancer was metastasis to the right ureter. We also analyse the available literature on lung cancer metastases to the ureter, taking into account the possible mechanisms of their spread in the ureter.

Galectin-9 expression on tumour-associated immune cells is associated with favourable clinicopathological features and better outcomes in oral squamous cell carcinoma.

Introduction: Galectin-9, a ß-galactoside-binding protein, might be a potential target in cancer personalized therapy, but contradicting data exist regarding its prognostic significance in malignancy. Previous studies showed low or absent expression of galectin-9 on tumour cells of oral squamous cell carcinoma (OSCC); thus, we aimed to assess the prognostic impact of its expression on tumour-associated immune cells (TAICs). Material and methods: A retrospective analysis was conducted on 62 patients with OSCC. Tissue microarrays were constructed with chemo- and radiotherapy-naïve tissue samples and stained with anti-galectin-9 antibody. Cytoplasmic reactions in TAICs were counted as positive, and the percentage of galectin-9-positive cells was calculated. Results: The expression of galectin-9 was not associated with any demographic factors, other than diabetes mellitus type 2, for which there were lower levels of expression (p = 0.029). Higher levels of galectin-9 were associated with less locally advanced tumours (p = 0.023) and lack of nodal metastases (p = 0.014). Galectin-9 expression positively correlated with PD-L1 expression on TAICs (p = 0.009). Patients with > 50% galectin-9-positive cells were determined to have a superior 5-year overall survival (p = 0.029). Conclusions: Future studies are necessary to investigate the effects of galectin-9 on the tumour micro-environment, and galectin-9-targeted treatment may be considered, especially with its correlation to PD-L1 in OSCC.

Diagnostically misleading aberrant terminal deoxynucleotidyl transferase expression in germ cell tumors.

Terminal deoxynucleotidyl transferase (TdT) is a unique type of DNA polymerase predominantly expressed in precursor lymphoid cells and acute lymphoblastic leukemia. It participates in the junctional diversity of T-cell receptors and immunoglobulins. Recently, aberrant TdT expression was found in seminomas. Here, we evaluated the expression of TdT in our cohort of germ cell tumors (GCTs) with two anti-TdT antibody clones. We included 173 cases of testicular GCTs, 5 ovarian dysgerminomas, and one gonadoblastoma in the study. Tissue microarrays containing representative tumor samples were constructed and subsequently stained with anti-TdT monoclonal rabbit antibody EP266 (Dako) and TdT rabbit polyclonal antibody (Cell Marque). Expression was assessed with the H-score. No specific nuclear reaction was observed for the polyclonal anti-TdT antibody. The H-score values varied between the histological subtypes for the EP266 antibody. Positive nuclear staining was consistently seen in germ cell neoplasia in situ , seminoma, dysgerminoma, and embryonal carcinoma. Pure tumors had higher TdT H-scores than the mixed ones. Teratomas, yolk sac tumors, and choriocarcinomas were almost uniformly negative. Our study confirms that aberrant expression of TdT by testicular and ovarian GCTs exemplifies a potential diagnostic pitfall in histopathological diagnostics.

Adrenal Tumors in Young Adults: Case Reports and Literature Review.

The current high detection rate of adrenal tumors (4-10% of general population) is attributable to a widespread use of variety of imaging studies, especially a computed tomography. Most of them represent clinically silent and biologically indolent incidentalomas, but some adrenal tumors may pose a significant clinical challenge. Thus, in every patient with an adrenal tumor, a decision on further management is made after careful hormonal and radiological evaluation. All hormonally active tumors and those with radiological features suggesting malignancy are qualified for surgery. Approximately 80% of adrenal tumors are adrenocortical adenomas, hypertrophy, or nodular adrenocortical hyperplasia. Other histopathological diagnoses include pheochromocytoma, adrenocortical carcinoma, metastases, mesenchymal tumors, lymphomas, cysts, and ganglioneuromas. Adrenal tumors are more commonly diagnosed and better studied in elderly patients. In younger patients, under 40 years old, focal adrenal lesions are relatively rare, and histological distribution of diagnoses differs from that in elderly individuals. Younger patients are more likely to display endocrine symptoms, which raise the suspicion of an adrenal mass. In the current study, we present a case series of seven adrenal tumors occurring in young patients. The cases presented below, along with the literature review, demonstrate that the diagnosis and treatment of adrenal tumors are crucial due to endocrinopathy-derived complications and a potential risk of malignancy.

Comparison of claudin-3 and claudin-4 expression in bilateral and unilateral breast cancer.

Claudins are essential components of tight junctions, which are frequently deregulated in breast cancer. The aim of the current study was to assess claudin-3 and -4 expression in bilateral breast cancer (BBC) and unilateral breast cancer (UBC). Immunohistochemical expression of claudin-3 and claudin-4 was evaluated in tissue microarrays containing 174 cases of BBCs paired with 174 cases of solitary tumors. Each case was classified as claudin-high or claudin-low depending on the H-score value. The results were correlated with histopathological features and the expression of basic breast cancer biomarkers. Median H-scores for claudin-3 were significantly higher in the synchronous BBC (sBBC) than in UBC. Claudin-4-high cases were more prevalent than within the whole BBC group, and sBBC and metachronous BBC (mBBC) alone. In the BBC group negative ER, high Ki-67 and high claudin-3 were independent factors correlated with high claudin-4. In the UBC group, Ki-67 >14% and high claudin-3 were associated with high claudin-4. Our study demonstrates that the expression of claudin-4 is significantly higher in UBC compared to BBC tumors. We also demonstrated that high claudin-4 expression in BBC is associated with a more aggressive phenotype (lack of steroid receptors, HER2 overexpression, and high Ki-67). It is possible that claudins down- and upregulation may depend on different triggers and lead to various consequences in UBC and BBC.

Skene's gland adenocarcinoma coexisting with infiltrating urothelial carcinoma of the urinary bladder.

A 78-year-old woman underwent radical cystectomy due to high-grade infiltrating urothelial carcinoma of the urinary bladder. Histopathological examination of the bladder neck revealed coincidental urothelial carcinoma and tubular neoplasm resembling prostatic acinar adenocarcinoma. The latter was accompanied by a non-invasive component showing features of high-grade prostatic intraepithelial neoplasia (PIN). The lesion showed immunopositivity for prostate-specific antigen, prostein, and androgen receptor. The diagnosis of Skene's gland adenocarcinoma (SGA) was established. This is the 14th case of SGA in the literature, and the first coexisting with urothelial carcinoma. Our case demonstrates a possible origin of SGA from precursors resembling PIN.

Who Is a Pathologist According to Oncology Patients and Internet Users? A Survey Study.

The pathologist is frequently called "the doctor's doctor." However, there are many uncertainties about the role of a pathologist among patients and policymakers and even among other medical specialties. The aim of the current study is to analyze the misconceptions of who a pathologist is among inpatients and Internet users, to find where the lack of understanding is originating from, and to confirm the need to educate the general public about pathologists. The survey of Internet users was conducted among Facebook users, utilizing the snowball sampling method. Inpatients were randomly recruited in the Department of Surgical Oncology. Seventy-eight inpatients and 320 Internet users were enrolled in the study. Significantly, more hospital patients than Internet users answered that the pathologist is not an MD (p = 0.00953). A portion of participants stated that pathologists do not make diagnoses (n = 28, 7.03%) and do not influence the treatment plan (n = 37, 9.30%) and that the other specialists do not gain anything from the pathologist's work (n = 67, 16.83%). Only 15.07% of respondents had their information about pathologists from other doctors. The findings from this study should show that even the most basic knowledge of a pathologist being an MD is not known. Pathologists are not recognized for being involved in the diagnosis of diseases. This should provide an incentive to pathologists to teach future doctors, policymakers, and patients about the perplexity of the pathology specialty. It shows obvious gaps in the knowledge of the treatment process as a whole.

Immunohistochemical evaluation of mismatch repair proteins and p53 expression in extrauterine carcinosarcoma/sarcomatoid carcinoma.

INTRODUCTION: Carcinosarcoma (CS) is a tumor with components: epithelial (carcinomatous) and mesenchymal (sarcomatous), developing in the mechanism of epithelial-mesenchymal transition. It is known that the p53 defect is a frequent finding in a carcinosarcoma in different anatomical locations, additionally, in a subgroup of uterine CS MMR defect plays a role in the pathogenesis. The aim of this paper was to investigate the frequency of MMR and p53 aberrations in extrauterine CS. MATERIAL AND METHODS: Twenty eight extrauterine CS from the lung (n = 8), breast (n = 6), head and neck (n = 5), ovary (n = 3), urinary bladder (n = 3), adrenal gland (n = 1), skin (n = 1), and stomach (n = 1) were stained for hMLH1, PMS2, hMSH2, hMSH6 and p53. The pattern of expression was evaluated separately in carcinomatous and sarcomatous component. RESULTS: Immunostainings for hMLH1, PMS2, hMSH2 and hMSH6 were positive in all tumors. p53 defect was observed in 19 out of 28 samples (67.85%). In all cases except one (96.42%) there was a concordance between sarcomatoid and carcinomatous components. CONCLUSIONS: MMR deficiency does not seem to play a role in the pathogenesis of extrauterine CS. p53 aberrant expression is frequent and almost always consistent in carcinomatous and sarcomatous component.

Tumour expressions of hypoxic markers predict the response to neo-adjuvant chemotherapy in children with inoperable rhabdomyosarcoma.

Objective: The study was to assess whether tumour expressions of hypoxia-inducible factor (HIF)-1α, glucose transporter (GLUT)-1, carbonic anhydrase (CA) IX and vascular endothelial growth factor (VEGF) predict response to neo-adjuvant chemotherapy (naCHT) in children with inoperable rhabdomyosarcoma (RMS). Methods: Immunohistochemical expressions of hypoxia markers were determined semi-quantitatively in tumour tissue microarray of 46 patients with embryonal RMS (RME) and 20 with alveolar (RMA), treated with CWS protocols (1992-2013). Results: In paediatric RME, response to naCHT was influenced significantly by tumour expression of CA IX and GLUT-1. Patients with RMA with low expressions of analysed markers responded well to naCHT, while all poor-responders expressed highly hypoxia markers. Only 5.88% of RMA and 11.11% of RME tumours did not express any of the proteins. In both RME and RMA subgroups, most poor-responders demonstrated simultaneous high expression of ≥3 markers, while most patients expressing ≤2 markers responded well to naCHT. In the whole cohort, co-expression of ≥3 markers, was the only independent factor predicting poor-response to chemotherapy (odds ratio 14.706; 95% CI 1.72-125.75; p = 0.014). Conclusions: Immunohistochemical expression pattern of four endogenous markers of hypoxia, in tumour tissue at diagnosis, emerges as a promising tool to predict response to naCHT in children with inoperable RMS.

Carcinoma Cuniculatum of the Lower Leg: A Case Report and Proposed Diagnostic Criteria.

Carcinoma cuniculatum is an infrequent variant of squamous cell carcinoma described for the first time by Ian Aird in 1954. Since then, multiple reports of cutaneous carcinoma cuniculatum have been published at various sites, including palms, soles, buttocks, and lower legs, but most of them did not match to original description. In the current study, we report a unique case of a 69-year-old woman with carcinoma cuniculatum arising in the calf. Moreover, we update the histopathological criteria of cutaneous carcinoma cuniculatum by combining the literature descriptions and the experiences from the current case.

MLH1 promoter hypermethylation in uterine carcinosarcoma rarely coexists with TP53 mutation.

INTRODUCTION: Carcinosarcoma (CS) is an infrequent neoplasm composed of a carcinomatous and a sarcomatous element. Its molecular pathogenesis is poorly understood. In this study, we investigated the disturbances in the immunohistochemical expression of p53 and mismatch repair (MMR) proteins, as well as their molecular background. MATERIAL AND METHODS: The study group consisted of 20 uterine CSs. We analysed their morphology and immunohistochemical expression of hMLH1, hPMS2, hMSH2, MSH6, and p53 as well as the presence of mutations in TP53 and promoter methylation of the hMLH1. Loss of hMLH1 and PMS2 was found in 3/20 tumours. All cases were positive for hMSH2 and hMSH6. The TP53 mutation was detected in 8/19 tumours (42.1%), whereas MLH1 promoter hypermethylation in 4/19 cases (21%), and one case with synchronous aberrations (5%). Agreement between the results of the genetic and immunohistochemical study was moderate for p53 (k = 0.615, p< 0.01) and strong for MLH1 (k = 0.826, p< 0.01). RESULTS AND CONCLUSIONS: We demonstrated MLH1 promoter hypermethylation in uterine CS, leading to loss of MLH1 immunostaining. Concomitant aberrations of p53 and hMLH1 are infrequent. It is likely that uterine CS may develop in two independent molecular pathways in association with either chromosomal or microsatellite instability.

Paraneoplastic syndromes in olfactory neuroblastoma.

Olfactory neuroblastoma (ONB) is a rare malignant neoplasm of sinonasal tract, derived from olfactory epithelium. Unilateral nasal obstruction, epistaxis, sinusitis, and headaches are common symptoms. Olfactory neuroblastoma shows neuroendocrine differentiation and similarly to other neuroendocrine tumors can produce several types of peptic substances and hormones. Excess production of these substances can be responsible for different types of endocrinological paraneoplastic syndromes (PNS). Moreover, besides endocrinological, in ONB may also occur neurological PNS, caused by immune cross-reactivity between tumor and normal host tissues in the nervous system. Paraneoplastic syndromes in ONB include: syndrome of inappropriate ADH secretion (SIADH), ectopic ACTH syndrome (EAS), humoral hypercalcemia of malignancy (HHM), hypertension due to catecholamine secretion by tumor, opsoclonus-myoclonus-ataxia (OMA) and paraneoplastic cerebellar degeneration. Paraneoplastic syndromes in ONB tend to have atypical features, therefore diagnosis may be difficult. In this review, we described initial symptoms, patterns of presentation, treatment and outcome of paraneoplastic syndromes in ONB, reported in the literature.

Tumor-Infiltrating Lymphocytes (TILs) in Breast Cancer: Prognostic and Predictive Significance across Molecular Subtypes.

Tumor-infiltrating lymphocytes (TILs) are pivotal in the immune response against breast cancer (BC), with their prognostic and predictive significance varying across BC subtypes. In triple-negative BC (TNBC), higher TIL levels correlate with improved prognosis and treatment response, guiding therapeutic strategies and potentially offering avenues for treatment de-escalation. In metastatic TNBC, TILs identify patients with enhanced immunotherapy response. HER2+ BC, similar to TNBC, exhibits positive correlations between TILs and treatment response, especially in neoadjuvant settings. Luminal BC generally has low TILs, with limited prognostic impact. Single hormone receptor-positive BCs show distinct TIL associations, emphasizing subtype-specific considerations. TILs in ductal carcinoma in situ (DCIS) display ambiguous prognostic significance, necessitating further investigation. Standardizing TIL assessment methods is crucial for unlocking their full potential as biomarkers, guiding treatment decisions, and enhancing patient care in BC.

Expression of the tumor antigens NY-ESO-1, tyrosinase, MAGE-A3, and TPTE in pediatric and adult melanoma: a retrospective case control study.

Tumor-associated antigens (TAAs) are potential targets for T cell-based immunotherapy approaches in cutaneous melanoma. BNT111, an investigational lipoplex-formulated mRNA-based therapeutic cancer vaccine encoding melanoma TAAs NY-ESO-1, tyrosinase, MAGE-A3, and TPTE, is undergoing clinical testing in adults. Expression of these TAAs in pediatric melanoma is unclear but is a prerequisite for feasibility of this treatment approach in children with melanoma. Our main objective was to characterize expression of those TAAs in pediatric melanomas compared to control cohorts. In this retrospective case control study, protein and transcript expression of NY-ESO-1, tyrosinase, MAGE-A3, and TPTE were analyzed in a cohort of 25 pediatric melanomas, 31 melanomas of young adults, 29 adult melanomas, and 30 benign melanocytic nevi in children using immunohistochemical staining and digital pathology (QuPath) and reverse transcription quantitative PCR. Based on IHC analysis, pediatric melanomas expressed tyrosinase (100.0%), TPTE (44.0%), MAGE-A3 (12.0%), and NY-ESO-1 (8.0%). Young adult melanomas expressed tyrosinase (96.8%), NY-ESO-1 (19.4%), MAGE-A3 (19.4%), and TPTE (3.2%). Adult melanomas expressed tyrosinase (86.2%), MAGE-A3 (75.9%), NY-ESO-1 (48.3%), and TPTE (48.3%). Childhood melanocytic nevi only expressed tyrosinase (93.3%). Expression prevalence of individual TAAs did not differ between subtypes of pediatric melanoma, and no association with prognosis was found. All four TAAs were expressed in pediatric melanoma, albeit NY-ESO-1 and MAGE-A3 to a lesser extent than in adult melanoma. These data support the possibility of investigating vaccines targeting these TAAs for the treatment of pediatric melanoma.

Immune checkpoint receptor VISTA on immune cells is associated with expression of T-cell exhaustion marker TOX and worse prognosis in renal cell carcinoma with venous tumor thrombus.

PURPOSE: The study aimed to determine the expression of VISTA and TOX within venous tumor thrombus and primary clear cell renal cell carcinoma (ccRCC) and to assess their prognostic value. METHODS: The study enrolled 82 patients with ccRCC and coexisting venous tumor thrombus treated radically from 2012 to 2019 in two tertiary centers. Tissue microarrays were prepared and stained with respective antibodies. The expression of markers was assessed separately on tumor cells (TCs) and/or tumor-associated immune cells (TAICs). RESULTS: TOX expression was positively correlated with the percentage of VISTA-positive TAICs in venous thrombus (p = 0.011), but not in the primary tumor (p = 0.674). High TOX expression was associated with a higher percentage of PD-L1-positive TAICs in both compartments (p = 0.001, p = 0.011, respectively). Positive expression of VISTA on TAICs was associated with PD-L1 expression on TCs (p = 0.005) and TAICs (p = 0.004) in the primary tumor, and only with PD-L1 on TAICs in thrombus (p = 0.006). The presence of VISTA-positive TAICs in venous thrombus was significantly more common in females (p = 0.034), and positively correlated with metastases (p = 0.028), and tumor necrosis (p = 0.013). The cases with VISTA-positive TAICs in venous tumor thrombi had significantly shorter OS than VISTA-negative cases (p = 0.041). CONCLUSION: For the first time, we demonstrated the expression of VISTA- and TOX-positive TAICs in the venous tumor thrombus. We found the association between immune checkpoint receptors and T cell exhaustion markers in both tumor mass and venous thrombus. Finally, we demonstrated that abundance of VISTA-positive TAICs in venous tumor thrombus correlates with worse outcomes in ccRCC.

Extremely Rare Pulmonary Metastases of Skin Basal Cell Carcinoma: Report of Two Cases with Clinicopathological Features.

Basal cell carcinoma (BCC) is the most frequent human skin cancer, but metastasizing BCC (MBCC) is extremely rare, developing in approximately 0.0028% to 0.55% of BCC patients. Herein, we report two cases of pulmonary MBCC. The first one developed in a 72-year-old male who underwent surgical resection due to multiple recurrences and adjuvant radiotherapy. Immunohistochemistry showed that neoplastic cells expressed Ber-EP4, CK5/6, p63, EMA (focally), BCL-2, and CD10, but were negative for CK7, CK20, S100, estrogen and progesterone receptors, and TTF-1. The second case is a 64-year-old female treated with vismodegib. Clinicopathological features and differential diagnoses are described.