Clinicopathological analysis of basal cell carcinoma of the anal region and its distinction from basaloid squamous cell carcinoma

Clinicopathologic and Molecular Characterization of Basal Cell Carcinoma Arising at Sun-protected Sites

Basal cell carcinomas (BCC) are driven primarily by cumulative ultraviolet (UV) radiation exposure resulting in activation of the Hedgehog (Hh) signaling pathway, often as a result of UV-mediated Patched-1 ( PTCH1) gene inactivation. Accordingly, BCCs most commonly arise at sun-exposed sites such as the head and neck. Very rarely, BCCs can arise at sun-protected sites such as the genital skin and perianal area. This can pose significant diagnostic challenges not only due to the rarity of BCC at these sites but also due to the potential morphologic overlap with other entities such as basaloid squamous cell carcinoma, trichoblastic carcinoma, and even benign neoplasms such as trichoblastomas. Hh pathway alterations have not yet been described in BCCs arising at genital and perianal sites, and the role of UV radiation is uncertain at these anatomic locations. To address this ambiguity, we report the clinicopathologic features of a cohort of 14 BCCs arising at sun-protected sites (perianal n=7, vulva n=4, scrotum n=3). Furthermore, we use a next-generation DNA sequencing platform to investigate their pathogenesis and compare it to that of a cohort of 8 BCCs arising on sun-exposed skin. We find that BCCs arising on sun-protected sites display a spectrum of morphologic patterns, rarely recur, and do not metastasize. Both sun-protected and sun-exposed BCCs are characterized by recurrent PTCH1 alterations (93% and 100% of cases, respectively), supporting the classification of the tumors arising at sun-protected sites as bona fide BCCs. Notably, in contrast to conventional BCCs, none of the sun-protected BCCs harbored a UV mutation signature, suggesting an alternative mechanism of mutagenesis. Furthermore, the presence of upstream Hh pathway alterations in sun-protected BCCs supports their susceptibility to Hh pathway inhibitors such as vismodegib and sonidegib.

CYLD-mutated anal squamous cell carcinoma: An uncommon entity associated with cylindroma-like morphology and adverse clinical features

Anal squamous cell carcinoma (SqCC) can be broadly divided into HPV-positive and HPV-negative groups, each with distinct clinicopathologic features and outcome. CYLD-mutant anal SqCC was recently characterized as having a strong association with cylindroma-like histologic features, HPV positivity, infrequent PIK3CA mutation, and low tumor mutational burden. The prognostic impact of CYLD mutation in this context has not been established. We performed CYLD mutational analysis on a cohort of 109 clinicopathologically well-characterized cases of anal SqCC including 98 HPV-positive and 11 HPV-negative carcinomas. CYLD mutation was present in 3 cases (2.8 % of total, 3.1 % of HPV-positive cases), all of which were HPV16-positive. CYLD mutation was significantly associated with more frequent cylindroma-like basement membrane inclusions (p = 0.0002) and basaloid cytomorphology (p = 0.017). Just 4 % of CYLD-wildtype carcinomas demonstrated cylindroma-like features, which were limited in extent relative to CYLD-mutant cases. Among the HPV-positive group, CYLD mutation and cylindroma-like morphology were associated with a higher rate of metastatic disease progression (p = 0.022 and p = 0.01, respectively), with 2 of 3 CYLD-mutant patients developing liver metastasis at 6 and 7 months after initial diagnosis. None of the CYLD-mutant cases had other mutations including PIK3CA and TP53 mutations. Our findings further establish CYLD-mutant anal SqCC as an infrequent but distinct clinicopathologic entity with characteristic pathogenetic features and a possible association with adverse clinical outcomes. Among HPV-positive anal SqCC, CYLD mutation represents a potentially useful novel marker for this distinct entity and cylindroma-like morphology serves as a useful feature to identify such cases.

Anal carcinoma - exploring the epidemiology, risk factors, pathophysiology, diagnosis, and treatment

Anal carcinoma is a relatively rare tumor that accounts for approximately 2% of gastrointestinal malignancies and less than 7% of anorectal cancers. Most anal tumors originate between the anorectal junction and the anal verge. Risk factors for the disease include human papillomavirus infection, human immunodeficiency virus, tobacco use, immunosuppression, female sex, and older age. The pathogenesis of anal carcinoma is believed to be linked to human papillomavirus-related inflammation, leading to dysplasia and progression to cancer. Squamous cell carcinoma is the most common type of anal tumor, with an annual incidence of approximately 1 to 2 per 100000 persons. Treatment regarding anal cancer has emerged over time. However, chemoradiation therapy remains the mainstay approach for early localized disease. Patients with metastatic disease are treated with systemic therapy, and salvage surgery is reserved for disease recurrence following chemoradiation. This article aims to provide background information on the epidemiology, risk factors, pathology, diagnosis, and current trends in the management of anal cancer. Future directions are briefly discussed.

Pigmented basal cell carcinoma of the anus: a rare entity with diagnostic challenges

Anal cancer is uncommon, comprising 2.2% of gastrointestinal cancers. Squamous cell carcinoma (SCC) is the most common; while perianal basal cell carcinoma (BCC) is rare, representing only 0.2% of anorectal malignancies. BCC, associated with sun exposure and immunosuppression, often resembles benign conditions and manifests as perianal ulcers or masses. Histologically, BCC exhibits basaloid tumor cells with distinct patterns. Despite its rarity, accurate diagnosis is crucial. We expose a case study of a 59-year-old male, previously healthy, that presented with hematochezia and perianal pain, leading to a diagnosis of lower gastrointestinal bleeding. Colonoscopy was needed, and a biopsy revealed an ulcerated, indurated lesion involving the left lateral hemorrhoidal bundle, diagnosed as pigmented basaloid carcinoma. Microscopic examination showed malignant nests of cells with peripheral nuclear palisading, melanocytes, and melanin pigment. Immunohistochemistry confirmed positivity for p63, CK5/6, and BCL2. Respect the treatment, due to the involvement of the anal sphincteric muscle, radiotherapy was chosen.

Shining Light on a Dark Corner: A Case Report on Perianal Basal Cell Carcinoma

Perianal basal cell carcinoma (BCC) is a rare occurrence, with limited documented cases in the existing literature. The precise etiology contributing to its onset remains inadequately elucidated. Macroscopically, perianal BCC often exhibits atypical features, potentially leading to diagnostic challenges. Histopathological examination plays a crucial role in distinguishing BCC from other cutaneous lesions in this region. Despite its localized nature, perianal BCC generally carries a favorable prognosis characterized by a gradual progression. However, diligent follow-up is essential to mitigate the risk of recurrence. Our clinical observation highlights a noteworthy yet uncommon manifestation. The patient, a 64-year-old male, presented with a persistent perianal lesion evolving over a three-month period. Symptoms included intermittent bleeding and purulent discharge, exacerbating the clinical picture. A biopsy was subsequently performed, confirming the diagnosis of basal cell carcinoma. Following this, the patient underwent external beam radiation therapy as part of the treatment regimen.

Perianal Malignancies: A Review for the Dermatologic Surgeon

BACKGROUND

Perianal malignancies are rare tumors with unique presentations and treatment options.

OBJECTIVE

To review published literature about primary malignancies that present on perianal skin and published guidelines and treatment options.

MATERIALS AND METHODS

A PubMed search was conducted for original articles about perianal malignancies.

RESULTS

Squamous cell carcinoma, basal cell carcinoma, melanoma, and extramammary Paget disease are the most common tumors to present on perianal skin. Anal squamous cell carcinoma incidence is increasing and certain populations may benefit from screening. Surgical management is often recommended for localized perianal tumors.

CONCLUSION

Dermatologic surgeons should be familiar with the presentation and treatment options available for perianal malignancies.

Clinico-Pathological Profile of Basaloid Skin Tumors-Experience from a Tertiary Care Center of Eastern India

Basaloid tumors comprise a wide spectrum of benign and malignant tumors like basal cell carcinoma, seborrheic keratosis, pilomatricoma, basosquamous carcinoma, trichoblastoma, and cylindroma. Among them, basal cell carcinoma is the most common type which constitutes about 90% of all malignant skin tumor. This study was aimed at analyzing the clinico-pathological profile of basaloid skin tumors attending radiotherapy and surgery OPD of our institution and compares them with those of the reported literature from rest of the country as well as outside world. All cases of basaloid skin tumors presented at radiotherapy, surgery, and dermatology OPD between January 2020 and June 2021 with or without a histological diagnosis were evaluated. Those without a histological diagnosis underwent biopsy and categorized according to standard histological criteria. After histological confirmation, we collected demographic, clinical, and pathological data of the cases. Among 106 patients analyzed, 54.7% (58) cases were diagnosed as basal cell carcinoma followed by seborrheic keratosis (17.9%), pilomatricoma (13.2%), basosquamous carcinoma (9.4%), trichoblastoma (2.8%), and cylindroma (1.8%). Mean age of presentation was 57.03 (± 7.435) years, and head-neck region was the most common site of involvement for basal cell carcinoma. Twenty-two cases required immunohistochemical assessment for confirmation of diagnosis. To conclude, this study is one of its first from Eastern India and will act as a stepping stone for future studies concentrating on clinico-pathological profile, early diagnosis and treatment of basaloid skin tumors.

Perianal Basal Cell Carcinoma-A Systematic Review and Meta-Analysis of Real-World Data

(1) Background: BCC is a sporadic disease that develops in areas of the skin not exposed to the sun. Perianal BCC, which occurs in the anorectal region, accounts for less than 0.2% of all BCC cases. There have been only a few reported cases of the disease, with fewer than 200 cases reported in total. Given the diagnostic challenges and potential for misdiagnosis, we conducted a systematic review of perianal basal cell carcinoma using real-world data to provide comprehensive and detailed information on the disease. (2) Methods: The study was reported based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, 2020. Patients' clinical pathologic features, tumor characteristics, treatment modalities, and outcomes were presented. (3) Results: The results of 41 studies involving 140 patients were analyzed. The most common symptoms reported by patients at presentation were anorectal bleeding, pain, and pruritus. Ulceration was the most frequently observed tumor characteristic. The majority of patients underwent local excision as their primary treatment, with only eight patients experiencing a recurrence. Our analysis did not reveal any statistically significant differences in the outcomes of different treatment modalities. (4) Conclusions: Identifying perianal BCC poses a significant challenge as it closely resembles other anal diseases, thereby making it difficult to differentiate between the different conditions. However, a wide local excision with clear margins is considered an effective treatment option for most patients. Alternative treatments, such as radiotherapy, may be recommended for patients who are unable to undergo surgery.

Perianal basal cell carcinoma managed with wide excision and random flap reconstruction

Basal cell carcinoma (BCC) is a common skin malignancy and usually occurs in sun-exposed areas like the head and neck. Occurrence in the perianal area is rare, accounting for only 0.08% of all BCC, and 0.2% of anorectal malignancies.We present a case of a hypertensive woman in her 60s who had a 1-year history of a gradually enlarging mass on the left perianal region. Initial biopsy revealed a carcinoma with basaloid features and was confirmed on immunohistochemistry to be nodular BCC. Proctoscopy showed no intraluminal involvement. Contrast-enhanced chest and abdominal CT scans revealed no nodal or distant metastasis. MRI showed a 7.5 mm fat plane between the mass and the external sphincter muscles, projecting adequate surgical margins.A wide excision with at least 4 mm margins was performed. Reconstruction of the resulting defect was performed with a local random cutaneous flap.

A case report of the rarest anal cancer: Basal cell carcinoma

A 69-year-old male truck driver with history of chronic anal fissures and facial basal cell carcinoma developed rectal bleeding and pain, and was diagnosed with a 5cm basal cell cancer of the anus with sphincter invasion. His workup entailed physical exam, CT and MRI which confirmed external and internal sphincter invasion without evidence of distant metastatic disease. After review of chemoradiation and surgical options, the patient elected to proceed with robotic-assisted abdominoperineal resection with end colostomy with complex local-tissue reconstruction. He is now two years out and disease free. While radiation and surgery have both been described in the literature as viable treatments, surgical resection may be the best option for patients with large lesions with sphincter invasion, who travel from afar and have occupational restrictions. This case highlights the importance of a multidisciplinary approach in assessing the patient with a rare disease process, presenting all viable options for treatment, and electing the optimal treatment through shared decision making.

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Basal (BCC) cell carcinoma makes up less than 1% of anorectal neoplasms.

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Radiation, cryotherapy, Moh’s surgery, local excision, and abdominoperineal resection can be used for anal BCC.

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Due to it’s rarity, we recommend a multidisciplinary approach for this pathology.

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Details of a robotic abdominoperineal resection with complex perineal closure performed are discussed.

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The highlight of this report lies in honoring patient's wishes and what treatment best fits their lifestyle.

HPV-driven anal neoplasia: review and recent developments

A host of human papillomavirus (HPV)-associated squamous and glandular lesions may be identified in the anal canal in men and women. Given their relative rarity, familiarity with the morphological spectrum associated with HPV-driven anal neoplasia is important for proper identification and diagnosis. In this article, we review the classification and basic histopathological features of HPV-related squamous intraepithelial and invasive lesions as well as associated pitfalls. In addition, we provide an update on recently described HPV-driven, non-squamous tumours. As our experience with these lesions evolves, we expect the histological spectrum to further expand, particularly as it relates to non-squamous HPV-driven neoplasia.

CD56 expression in basaloid anal squamous cell carcinoma - A potential diagnostic pitfall

Anal squamous cell carcinoma (SqCC) is a morphologically heterogeneous entity. Basaloid and non-keratinizing anal SqCC may be confused with other tumors including neuroendocrine carcinoma due to morphologic overlap, and expression of neuroendocrine markers is not well-studied in anal SqCC. Prompted by a case of anal SqCC that was initially misdiagnosed as neuroendocrine carcinoma on the basis of morphology and CD56 expression, we retrospectively examined the expression of neuroendocrine markers CD56, synaptophysin, and chromogranin in 48 cases of basaloid anal SqCC, with clinicopathologic correlation. HPV16 was identified in 46 cases, HPV33 in one case, and one case was HPV-negative. Three (6.3%) cases demonstrated CD56 expression, including two with diffuse and one with focal expression. Two CD56-positive cases demonstrated basaloid morphology with peripheral palisading and the other demonstrated adenoid cystic/cylindroma-like morphology. None of the cases showed significant synaptophysin or chromogranin expression. The three cases expressing CD56 were HPV16-positive, and one demonstrated a CTNNB1 mutation. There was no difference in clinicopathologic features including stage, outcome, or HPV status, between CD56-positive and negative groups. Our findings support that CD56 expression is infrequently expressed in anal SqCC and is not indicative of neuroendocrine differentiation in the absence of expression of more specific neuroendocrine markers such as synaptophysin and chromogranin. Pathologists should be aware that CD56 expression may occur in basaloid anal SqCC and is a diagnostic pitfall due to morphologic overlap with neuroendocrine carcinoma and other tumors including basal cell carcinoma.

Molecular and immunophenotypic characterization of anal squamous cell carcinoma reveals distinct clinicopathologic groups associated with HPV and TP53 mutation status

Squamous cell carcinoma (SqCC) is the most common malignancy of the anal canal, where it is strongly associated with HPV infection. Characteristic genomic alterations have been identified in anal SqCC, but their clinical significance and correlation with HPV status, pathologic features, and immunohistochemical markers are not well established. We examined the molecular and clinicopathologic features of 96 HPV-positive and 20 HPV-negative anal SqCC. HPV types included 89 with HPV16, 2 combined HPV16/HPV18, and 5 HPV33. HPV-positive cases demonstrated frequent mutations or amplifications in PIK3CA (30%; p = 0.027) or FBXW7 mutations (10%). HPV-negativity was associated with frequent TP53 (53%; p = 0.00001) and CDKN2A (21%; p = 0.0045) mutations. P16 immunohistochemistry was positive in all HPV-positive cases and 3/20 HPV-negative cases (p < 0.0001; sensitivity: 100%; specificity: 85%) and was associated with basaloid morphology (p = 0.0031). Aberrant p53 immunohistochemical staining was 100% sensitive and specific for TP53 mutation (p < 0.0001). By the Kaplan-Meier method, HPV-negativity, aberrant p53 staining, and TP53 mutation were associated with inferior overall survival (OS) (p < 0.0001, p = 0.0103, p = 0.0103, respectively) and inferior recurrence-free survival (p = 0.133, p = 0.0064, and p = 0.0064, respectively). TP53/p53 status stratified survival probability by HPV status (p = 0.013), with HPV-negative/aberrant p53 staining associated with the worst OS, HPV-positive/wild-type p53 with best OS, and HPV-positive/aberrant p53 or HPV-negative/wild-type p53 with intermediate OS. On multivariate analysis HPV status (p = 0.0063), patient age (p = 0.0054), T stage (p = 0.039), and lymph node involvement (p = 0.044) were independently associated with OS. PD-L1 expression (CPS ≥ 1) was seen in 30% of HPV-positive and 40% of HPV-negative cases, and PD-L1 positivity was associated with a trend toward inferior OS within the HPV-negative group (p = 0.064). Our findings suggest that anal SqCC can be subclassified into clinically, pathologically, and molecularly distinct groups based on HPV and TP53 mutation status, and p16 and p53 immunohistochemistry represent a clinically useful method of predicting these prognostic groups.

Decreased Sox2 Messenger RNA Expression in Basal Cell Carcinoma

Background

Sox2, zeb1, and p21 have been implicated in aggressive behavior of squamous cell carcinoma (SCC) and melanoma. However, their expression level in basal cell carcinoma (BCC) has not been elucidated. We hypothesized BCC, contrary to SCC, and melanoma, could be a suitable model to study mechanisms which attenuate tumor metastasis. The aim of this study was to examine the messenger RNA (mRNA) expression levels of sox2, zeb1, and p21 in BCC.

Materials and Methods

Twenty-seven nonmetastatic BCC and twelve normal skin samples were evaluated using real-time reverse transcriptase polymerase chain reaction.

Results

The stemness marker sox2 demonstrated marked down-regulation, but zeb1 and p21 showed no significant change.

Conclusions

Here, we report a negative association between sox2 mRNA expression level and nonmetastatic BCC, thus, providing a likely explanation for the fact that normal skin is more reliant on sox2 than BCC. BCC may be using decreased sox2 mRNA to remain incognito from metastatic potential.

An Update on the Role of Immunohistochemistry in the Evaluation of Gastrointestinal Tract Disorders

As in other organ systems, immunohistochemistry (IHC) serves as an ancillary diagnostic tool for a wide variety of neoplastic and non-neoplastic disorders, including infections, work-up of inflammatory conditions, and subtyping neoplasms of the gastrointestinal (GI) tract. In addition, IHC is also used to detect a variety of prognostic and predictive molecular biomarkers for carcinomas of the GI tract. The purpose of this review is to highlight the use of IHC in common diagnostic scenarios throughout the tubular GI tract. The clinical indication and guidelines for performing IHC for detecting Helicobacter pylori is discussed along with role of gastrin and neuroendocrine markers in the diagnosis of autoimmune metaplastic atrophic gastritis. The major portion of this review discusses the use of IHC in the diagnostic workup of malignant neoplasms of the GI tract, such as adenocarcinoma versus squamous cell carcinoma, workup of poorly differentiated malignant neoplasms, and evaluation of uncommon gastric neoplasms (alpha-feto protein-producing carcinomas) and switch/sucrose-nonfermenting complex-deficient carcinomas. Lastly, localization of neuroendocrine tumors of unknown origin to aid clinical management, as well as HPV-driven anal neoplasia and IHC in the workup of basaloid anal neoplasms are also reviewed.

Liver metastatic basaloid squamous cell carcinoma with negative expression of pancytokeratin: a case report and literature review

Background

Basaloid squamous cell carcinoma (BSCC) is a rare subtype of squamous cell carcinoma with a high rate of distant metastasis. BSCC occurs most commonly in the esophagus, lungs, and head and neck. However, BSCC occurring in an atypical site without a known primary tumor and/or with the presence of atypical immunohistochemical features can result in delayed diagnosis or misdiagnosis.

Case presentation

Here, we report a case of a 67-year-old man with liver metastatic BSCC with negative pancytokeratin (AE1/AE3) expression. He presented with a chief complaint of epigastric discomfort. Imaging examination revealed a subcapsular mass in the right anterior lobe of the liver. Then, the patient underwent an irregular right hepatectomy. Grossly, the mass was gray, with a size of 7 × 7 × 4 cm. Microscopically, the mass comprised epithelioid tumor cells with both solid and pseudoadenoid structures, accompanied by necrosis. Immunohistochemical staining showed that the tumor cells were negative for AE1/AE3, CK18, CK7, CK19, Hepatocyte Paraffin-1, Glypican-3, Arginase-1, CD56, Chromogranin A, Synaptophysin, Vimentin, and Carcinoembryonic antigen. The Ki-67 index was 80%.The mass was diagnosed as a malignant tumor but could not be classified further. One month after surgery, the patient’s reexamination revealed esophageal tumor, and biopsy revealed BSCC. The slides of the liver tumor were reviewed, and the morphology was similar to that of the esophageal tumor. Moreover, supplementary immunohistochemical staining of liver tumor indicated p63 and p40 were strongly positive, that confirmed the liver tumor was metastatic BSCC. Previous studies have reported that 3.7% of esophageal BSCCs did not express AE1/AE3.

Conclusion

When a malignant tumor comprises epithelioid cells with solid and/or pseudoadenoid structures, but not adenocarcinoma or neuroendocrine carcinoma, even if the tumor cells are negative or weakly positive for AE1/AE3, we should consider BSCC. For a definite diagnosis, immunohistochemical staining for squamous cell carcinoma markers, including p63 and p40, and examination of common primary sites of BSCC should be performed.

Perianal Basal Cell Carcinoma Successfully Managed with Excisional Biopsy

Basal cell carcinoma (BCC) is the most common cutaneous malignancy in the United States and is often nonaggressive. Its location in the perianal region is very rare and it is estimated that only 0.08% of all BCCs occur in this region. Herein, we present a case of perianal basal cell carcinoma, nodular type. The diagnosis was made using excisional biopsy of a skin lesion. Immunohistochemical staining confirmed the diagnosis: it showed diffuse and strong positivity for smooth muscle actin (SMA) and monoclonal antibody BER-Ep4 and was negative for carcinoembryonic antigen (CEA), pancytokeratin (AE1/AE3), and epithelial membrane antigen (EMA). The treatment of choice has traditionally been local excision to clear margins but the newest guidelines recommend Mohs Micrographic surgery (MMS) or standard 4mm surgical margins for this high-risk BCC. Our patient was successfully treated using excisional biopsy without recurrence. In select patients with lesions smaller than 1cm, excisional biopsy may be sufficient to treat the disease and may be better tolerated than MMS and wider surgical margins. Literature review suggests a predisposition for perianal BCC in individuals susceptible to cutaneous malignancies. Therefore, any history of cutaneous malignancy should further prompt clinicians to examine nonsun exposed areas on full body skin exams.

A Case Report of Basal Cell Carcinoma in a Non-Sun-Exposed Area: A Rare Presentation Mimicking Recurrent Perianal Abscess

Basal cell carcinoma (BCC), a common malignancy, arises most often in sun-exposed areas but does rarely occur in non-sun-exposed sites. Prior tissue injury, especially sharp trauma and chronic inflammation, increases the risk of BCC. We describe a 66-year-old male patient with recurrent perianal abscesses who was found to have a large pigmented basal cell carcinoma. The mass was excised without recurrence at two-year follow-up. Perianal BCC is commonly larger at the time of diagnosis than tumors in sun-exposed sites, likely related to delay in diagnosis. Increased size can lead to increased surgical complexity and more pronounced effects on nearby structures. Early detection is important for optimal patient outcomes. In selected patients presenting with a perianal mass, basal cell carcinoma should be included on the differential diagnosis.

A Limited Immunohistochemical Panel to Distinguish Basal Cell Carcinoma of Cutaneous Origin From Basaloid Squamous Cell Carcinoma of the Head and Neck

Head and neck carcinomas with basaloid features can be diagnostically challenging. A common diagnostic issue is the distinction between a basaloid squamous cell carcinoma (bSCC) and a basal cell carcinoma (BCC) of cutaneous origin. This is particularly true in small biopsy specimens where classic architectural and histologic features may be difficult to appreciate. A specific diagnosis is essential because of significant differences in clinical outcome and therapeutic management. Ten resection cases of bSCC and BCC of the head and neck were selected based on primary location and the classic morphologic features that characterize these 2 entities. The following immunohistochemical markers were evaluated: epithelial membrane antigen (EMA), Ber-EP4, CD44, Bcl2, androgen receptor, SOX2, and p16. The strongest statistically significant differences in staining patterns were for EMA, p16, and SOX2. EMA was positive in all bSCCs and negative in all BCCs. SOX2 was positive in all bSCCs and in only 3 out of 10 BCCs. Staining was weak and peripheral in the SOX2-positive BCCs. p16 was positive in 8 out of 10 bSCCs and negative in all BCCs. We conclude that bSCC and BCC of the head and neck can be readily distinguished by a limited panel consisting primarily of EMA, and supported by SOX2 and p16.

The Use of BEREP4 Immunohistochemistry Staining for Detection of Basal Cell Carcinoma

Basal Cell Carcinoma (BCC) is the most common type of malignant cancer found in the world today with a 3–10% increase in incidence each year. The American Cancer Society reported that 8 out of 10 patients with skin cancer are suffering from BCC with over 2 million new cases each year. BCC needs to be detected at the early stages to prevent local destruction causing disabilities to patients and increasing treatment costs. Furthermore, BCC patients who have undergone surgery are still at risk for recurrence, especially when the surgery performed fails to remove all the BCC cells, even when conventional histopathological testing after surgery has reported a surgically free margin. This review aims to evaluate studies on the use of BerEP4 immunohistochemistry staining on pathological sections of various types of BCC as well as its shortfalls. BerEP4 is a monoclonal antibody which detects specific epithelial-glycoprotein-adhesion-molecules (EpCAM) found on BCC cells. Various studies have shown that BerEP4 has a high sensitivity and specificity in detecting only BCC cells. The use of BerEP4 immunohistochemistry testing for the routine examination of cases of BCC is expected to be able to increase and improve early diagnosis as well as prevent recurrence after surgery.

Noninvasive Papillary Basal-like Urothelial Carcinoma: A Subgroup of Urothelial Carcinomas With Immunohistochemical Features of Basal Urothelial Cells Associated With a High Rate of Recurrence and Progression

BACKGROUND

We investigated the clinical and pathologic significance of a subgroup of noninvasive papillary urothelial carcinomas (UCs) expressing reactivity to urothelial basal cell markers.

DESIGN

In total, 302 consecutive cases of noninvasive papillary UC were evaluated immunohistochemically with cytokeratin 5 (CK5)/CD44. Any UC that was reactive for greater than 25% thickness of the urothelium was designated as basal-like urothelial carcinoma (BUC); remaining UC cases were designated as non-BUC. The follow-up period was up to 3 years. Historical review of UC was extended for up to 3 retrospective years.

RESULTS

Among 302 noninvasive UC, BUC was identified in 33 of 256 (12.9%) low-grade UC and 8 of 46 (17%) high-grade UC (P=0.041). Immunoreactivity for CD44 was similar to that of CK5, but displayed weaker and more diffuse staining. CK20 was reactive in 9 cases, primarily high-grade BUC. Other basal cell markers (34bE12, p63, bcl2, and EP4) were found to be neither sensitive nor specific in detecting UC with high CK5 expression. In comparison with non-BUC, BUC was associated with increased multifocality, larger tumor size, higher recurrence rate, and more frequent upgrading and stage progression. In the follow-up period of 3 years, distant metastasis occurred in 6 cases of which 5 were in the BUC subgroup.

CONCLUSIONS

Our results showed that noninvasive papillary BUC represents a small subset associated with increased risk of tumor recurrence and progression. The aggressive behavior is likely associated with basal-like features of BUC, as seen in carcinomas with basal cell features in other body sites.

Basaloid Squamous Cell Carcinoma of the Head and Neck: Subclassification into Basal, Ductal, and Mixed Subtypes Based on Comparison of Clinico-pathologic Features and Expression of p53, Cyclin D1, Epidermal Growth Factor Receptor, p16, and Human Papillomavirus

Background

Basaloid squamous cell carcinoma (BSCC) is a rare variant of squamous cell carcinoma with distinct pathologic characteristics. The histogenesis of BSCC is not fully understood, and the cancer has been suggested to originate from a totipotent primitive cell in the basal cell layer of the surface epithelium or in the proximal duct of secretory glands.

Methods

Twenty-six cases of head and neck BSCC from Asan Medical Center, Seoul, Korea, reported during a 14-year-period were subclassified into basal, ductal, and mixed subtypes according to the expression of basal (cytokeratin [CK] 5/6, p63) or ductal markers (CK7, CK8/18). The cases were also subject to immunohistochemical study for CK19, p53, cyclin D1, epidermal growth factor receptor (EGFR), and p16 and to in situ hybridization for human papillomavirus (HPV), and the results were clinico-pathologically compared.

Results

Mixed subtype (12 cases) was the most common, and these cases showed hypopharyngeal predilection, older age, and higher expression of CK19, p53, and EGFR than other subtypes. The basal subtype (nine cases) showed frequent comedo-necrosis and high expression of cyclin D1. The ductal subtype (five cases) showed the lowest expression of p53, cyclin D1, and EGFR. A small number of p16- and/or HPV-positive cases were not restricted to one subtype. BSCC was the cause of death in 19 patients, and the average follow-up period for all patients was 79.5 months. Overall survival among the three subtypes was not significantly different.

Conclusions

The results of this study suggest a heterogeneous pathogenesis of head and neck BSCC. Each subtype showed variable histology and immunoprofiles, although the clinical implication of heterogeneity was not determined in this study.

SOX2 Expression in Cervical Intraepithelial Neoplasia Grade 3 (CIN3) and Superficially Invasive (Stage IA1) Squamous Carcinoma of the Cervix

The transcription factor SOX2 plays an important role in tissue development and differentiation. In the neoplastic context, SOX2 has been shown to potentiate tumor invasion, and increased SOX2 immunoreactivity has been demonstrated in a variety of epithelial and nonepithelial malignancies often correlating with adverse prognosis. There are limited data on SOX2 expression in cervical squamous neoplasia and in particular, no studies have compared staining in cervical intraepithelial neoplasia (CIN)3 and in superficially invasive (Stage IA1) squamous cell carcinomas (SCC). We examined SOX2 expression in 12 cervical biopsies showing CIN3 only and 30 specimens with an initial diagnosis of Stage IA1 SCC; 7 of the latter samples did not demonstrate residual invasive foci in the study slides but all showed CIN3. There was variable staining in CIN3 without stromal invasion but CIN3 adjacent to SCC was more often SOX2 positive with 70% cases showing diffuse staining. CIN within endocervical crypts often showed more extensive SOX2 expression and in some cases staining was restricted to areas of crypt involvement. In contrast to CIN, most SCCs were SOX2 negative and there was often an abrupt loss of expression at the tumor-stromal interface. In summary, CIN3 usually showed increased SOX2 expression compared with normal epithelium, particularly in areas of endocervical crypt involvement and adjacent to superficially invasive SCC. However, most invasive tumor cells were unstained suggesting downregulation of SOX2 during the initial stages of the invasive process. Progression of cervical squamous neoplasia may involve cyclical alterations in SOX2 activity.

Basaloid Squamous Cell Carcinoma of the Anus Revisited

Basaloid squamous cell carcinoma (SCC) of the anus, previously called cloacogenic carcinoma, is a subtype of SCC. There are very few data on the morphologic variation within basaloid SCC of the anus, which may contribute to misdiagnosis. We retrospectively evaluated cases originally diagnosed as basaloid SCC for histologic characterization. We retrieved and reviewed cases of basaloid SCC from 1994 to 2013. Ten (27%) cases were reclassified after review, including basal cell carcinoma (n=6), melanoma (n=2), and neuroendocrine carcinoma (n=2). The final group of basaloid SCC (n=27) showed a female predominance (median age=60 y; range, 42 to 92 y). Morphologically, basaloid SCC could be categorized into 4 groups: transitional carcinoma like (n=10), basaloid with peripheral palisade (n=13), adenoid cystic carcinoma like (n=3), and mucinous microcystic (n=1). In 19 cases the histologic patterns were pure and were mixed in the remainder. CK5/6, p16, and high-risk HPV were positive in all cases (n=27). SOX2 was positive in 18/22 cases. Clinical follow-up was available on 60% of cases; 9 patients (53%) developed local recurrence or metastasis, and 5 (29%) died of disease. Basaloid SCC of the anus is characterized by 4 major histologic patterns and is consistently HPV driven.

Tumours and inflammatory lesions of the anal canal and perianal skin revisited: an update and practical approach

Tumours of the anal and perianal region are relatively rare, and clinically often interpreted as innocuous lesions, leading to frequent delays in diagnosis and adequate treatment. Although squamous cell neoplasia represents the most common entity encountered in this anatomically complex area, many conditions, both neoplastic and inflammatory, may occur. Adding to the challenge of correct diagnosis and patient management, recent years have seen major updates in the terminology of squamous cell neoplasia, created to reflect advances in our understanding of the role of human papilloma virus and unify previous terminologies used for different sites in the anogenital tract. However, squamous cell neoplasia in the anal canal and perianal region may differ in terms of histology, biological behaviour, staging and treatment. The aim of this review is to present an overview of neoplastic and non-neoplastic lesions that may be seen in this area, an update on important developments and terminology, potential pitfalls that may be encountered in routine pathology practice and a practical approach on how to resolve these issues.

Differential senescence capacities in meibomian gland carcinoma and basal cell carcinoma

Meibomian gland carcinoma (MGC) and basal cell carcinoma (BCC) are common eyelid carcinomas that exhibit highly dissimilar degrees of proliferation and prognoses. We address here the question of the differential mechanisms between these two eyelid cancers that explain their different outcome. A total of 102 confirmed MGC and 175 diagnosed BCC cases were analyzed. Twenty confirmed MGC and twenty diagnosed BCC cases were collected to determine the telomere length, the presence of senescent cells, and the expression levels of the telomere capping shelterin complex, P53, and the E3 ubiquitin ligase Siah1. Decreased protein levels of the shelterin subunits, shortened telomere length, over-expressed Ki-67, and Bcl2 as well as mutations in P53 were detected both in MGC and BCC. It suggests that the decreased protein levels of the shelterin complex and the shortened telomere length contribute to the tumorigenesis of MGC and BCC. However, several parameters distinguish MGC from BCC samples: (i) the mRNA level of the shelterin subunits decreased in MGC but it increased in BCC; (ii) P53 was more highly mutated in MGC; (iii) Siah1 mRNA was over-expressed in BCC; (iv) BCC samples contain a higher level of senescent cells; (v) Ki-67 and Bcl2 expression were lower in BCC. These results support a model where a preserved P53 checkpoint in BCC leads to cellular senescence and reduced tumor proliferation as compared to MGC.

Invasive urothelial carcinoma exhibiting basal cell immunohistochemical markers: A variant of urothelial carcinoma associated with aggressive features

We characterize invasive urothelial carcinoma (UC) exhibiting urothelial basal cell immunohistochemical markers. Consecutive invasive UCs were immunostained with CK20 and urothelial basal cell markers, cytokeratin 5 (CK5)/CD44. Immunostaining for CK5 and CD44 was scored as follows: positive for staining of more than 25% thickness of the epithelial nest or epithelium and low for lesser immunoreactivity. Invasive urothelial carcinoma (UC) exhibiting positive CK5/CD44 staining was designated as basal-like UC (BUC). In this study, of 251 invasive UC (pT1 in 57% and pT2-4 in 43%), BUC accounted for 40% of cases (accounting for most pT2-4 UC) and often presented as non-papillary UC without previous history of UC. In addition, BUC exhibited uniform nuclei with lesser degree of atypia than non BUC and decreased or negative cytokeratin 20 reactivity. Nested and microcystic variants of UC immunohistochemically stained as BUCs. Invasive non-BUCs were often papillary with marked cytologic atypia and pleomorphism, and accounted for most pT1 UC. The rates of perivesical invasion, lymph node and distant metastases were higher for BUC than non-BUC. All nine cases with absent/minimal residual in situ UC in 102 radical cystectomy specimens were from invasive non-BUC. BUC is distinguished from non-BUC due to this aggressive behavior, distinct immunohistochemical profile, and predominant non-papillary architecture. Our findings are consistent with recent studies identifying a subtype of muscle-invasive UC with molecular expression of basal cell and luminal cell molecular profiles. Our study further supports categorizing invasive UCs into these subtypes with different biological behaviors, possibly contributing to better therapeutic strategies.

Perianal Basal cell carcinoma

Basal cell carcinoma (BCC) is the most common non-melanoma skin cancer. Exposure to ultraviolet light is an important risk factor for BCC development and the disorder therefore develops commonly on body areas that are more exposed to sunlight, such as the face and neck. It is uncommon in the closed area of the body and quite rare in the perianal and genital regions. Herein, we report a 34-year-old patient with perianal BCC who had no additional risk factors.