Immunoreactivity for alpha-smooth muscle actin characterizes a potentially aggressive subgroup of little basal cell carcinomas

A Comparative Study of CD56 and Smooth Muscle Actin Expression in Basal and Squamous Cell Carcinomas

ABSTRACT

Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are the 2 most common types of nonmelanoma skin tumors. Clinical or histopathological diagnostic challenges are encountered on occasion. CD56 and smooth muscle actin (SMA) are highly expressed in BCCs. We aimed to investigate the frequency of these markers, along with B-cell lymphoma 2 (Bcl-2) and Ki67. This study was conducted to propose a method that could possibly be of diagnostic value. One hundred twenty-eight BCC and 39 SCC cases were included in this study. CD56, SMA, Bcl-2, and Ki67 immunohistochemical stains were applied. Ninety-nine (77.3%) BCC and 6 (15.4%) SCC cases showed CD56 immunoreactivity. SMA expression was detected in 78.1% of BCC and 5.1% of SCC cases. CD56, SMA, and Bcl-2 expressions were significantly higher in BCC cases. The Ki67 proliferation index was found significantly higher in SCC cases. When basosquamous carcinoma cases were compared with SCC cases, a significant correlation between tumors and expression of CD56, SMA, and Bcl-2 were obtained. CD56 and SMA, in addition to Bcl-2, favor BCC. Ki67 should also be included in the panel to demonstrate the proliferative activity.

Recurrent nasal basal cell carcinoma treated with standard surgery excision: evaluation of volume ratio

BACKGROUND

Basal cell carcinoma (BCC) is the most common malignant skin tumor. Although it rarely evolves into a metastatic disease, BCC can lead to a significant morbidity due to local invasion. The risk of lesion recurrence depends on clinical and histopathological factors as described by the Nation Comprehensive Cancer Network (NCCN). The surgical excision margins have a well-known role: there is a close relationship between high recurrence rate of BCC and the tumor proximity to the surgical margins. Aim of our study was to assess whether there is a significative correlation between recurring BCC and volume ratio (VRb/t), defined as ratio between excisional biopsy volume and tumor volume, and if VRb/t is a useful parameter to assess the risk of recurrence of BCC.

METHODS

Retrospective case-control study in 80 patients with history of recurrent basal cell carcinoma of the nose (cases), and 43 patients with history of basal cell carcinoma of the nose with no evidence of relapse (controls) in the following 8 years.

RESULTS

Surgical excision margins, histological subtype, ulceration, depth of invasion and volume ratio (VRb/t) were evaluated in case and controls. The evaluation of VRb/t evidenced a significant difference between recurrent BCC and non-recurrent BCC. The mean values of VRb/t were 6.17 for cases and 11.94 for controls. The Binomial Logistic Regression has displayed, for values of VRb/t around 7, a probability of 75% to identify BCCs belonging to the recurrent group.

CONCLUSIONS

Our data show a significant correlation between recurrent BCCs and VRb/t. VRb/t can help in the assessment of recurrence risk, used together with others prognostic factor. For values of VRb/t close to 7 it should be recommended a close follow-up to promptly identify a possible recurrence.

CD56 and smooth muscle actin immunoreactivity in basal cell carcinomas: Are they indicators of differentiation or do they hold a diagnostic use?

BACKGROUND

Basal cell carcinoma (BCC) is the most common cutaneous malignancy and may show various differentiations. The possible pluripotent stem cell lineage of BCCs, whose origins are controversial today, is thought to be the main reason for the different morphologies. The aim of the study is to evaluate the expression of some neuroendocrine and smooth muscle markers of differentiation in BCCs and investigate the relationship between histopathologic subtypes and recurrence.

METHODS

A total of 128 cases diagnosed as BCC in our center were included. Immunohistochemical studies of CD56, synaptophysin, chromogranin-A, smooth muscle actin (SMA), desmin, caldesmon, and Ki67 were applied.

RESULTS

CD56, chromogranin-A, and synaptophysin immunoreactivity were detected in 77.3%, 13.3%, and 0.8% of the cases, respectively. 78.1% showed SMA positivity while no tumor expressed desmin or caldesmon. A correlation between histopathologic recurrence risk groups and CD56 expression was found (p < 0.05).

CONCLUSIONS

CD56 and SMA immunoreactivity is present in the majority of BCCs. However, the available findings do not support neuroendocrine or smooth muscle differentiation. CD56 antigen can be used for prognostic purposes in detecting high recurrence risk tumors. After the investigation of the expression rates of these two antigens in different cutaneous tumors, it may be appropriate to use them for diagnostic purposes in BCCs.

Myofibroblast stroma differentiation in infiltrative basal cell carcinoma is accompanied by regulatory T-cells

INTRODUCTION

The implications of infiltrative compared to non-infiltrative growth of cutaneous basal cell carcinoma (BCC) on the tumor stroma and immune cell landscape are unknown. This is of clinical importance, because infiltrative BCCs, in contrast to other BCC subtypes, are more likely to relapse after surgery and radiotherapy.

MATERIALS AND METHODS

This descriptive cross-sectional study analyzed 38 BCCs collected from 2018 to 2021. In the first cohort (n = 28), immune cells were characterized by immunohistochemistry and multiplex immunofluorescence staining for CD3, CD8, CD68, Foxp3, and α-SMA protein expression. In the second cohort (n = 10) with matched characteristics (age, sex, location, and BCC subtype), inflammatory parameters, including TGF-β1, TGF-β2, ACTA2, IL-10, IL-12A, and Foxp3, were quantified via RT-qPCR after isolating mRNA from BCC tissue samples and perilesional skin.

RESULTS

Infiltrative BCCs showed significantly increased levels of α-SMA expression in fibroblasts (p = 0.0001) and higher levels of Foxp3+ (p = 0.0023) and CD3+ (p = 0.0443) T-cells compared to non-infiltrative BCCs. CD3+ (p = 0.0171) and regulatory T-cells (p = 0.0026) were significantly increased in α-SMA-positive tumor stroma, whereas CD8+ T-cells (p = 0.1329) and CD68+ myeloid cells (p = 0.2337) were not affected. TGF-β1 and TGF-β2 correlated significantly with ACTA2/α-SMA mRNA expression (p = 0.020, p = 0.005).

CONCLUSION

Infiltrative growth of BCCs shows a myofibroblastic stroma differentiation and is accompanied by an immunosuppressive tumor microenvironment.

Basal cell carcinoma in an albino pindani (Chindongo socolofi) and a cobalt-zebra (Maylandia callainos): Diagnostic imaging, clinical and histopathological study

A female albino pindani (Chindongo socolofi) and female cobalt-zebra (Maylandia callainos) were referred to the Ornamental Fish Clinic with a soft tissue mass on their upper jaw. Also, during clinical examination, an unencapsulated intraoral soft tissue mass was observed in the cobalt-zebra cichlid. Digital radiography showed soft tissue masses and osteolytic lesions. Computed tomography (CT) imaging confirmed that osteolytic lesions occurred in skull bones of cobalt-zebra. Also, soft tissue mass invaded to the intraoral space. Histopathologically, a non-encapsulated, multilobulated and densely cellular neoplastic mass was identified. Extensive infiltration of neoplastic cells to the dermis and subcutaneous tissue was observed in both cases. The masses were composed of multiple coalescing nests, sheets, lobules and trabeculae of neoplastic cells within a fibrovascular stroma. The palisading basaloid neoplastic cells were markedly extended from the basal cells of the epidermis into the dermis and subcutis. The majority of the neoplastic cells had scant amounts of eosinophilic cytoplasm with indistinct margins, round to ovoid nuclei and typically a single small basophilic nucleolus. There was invasion of basaloid neoplastic cells into the bone tissue that caused osteolytic lesions. Mitotic figures were three to seven per high-power field. Epidermal basement membrane was periodic acid-Schiff (PAS) positive and neoplastic cell extension into the dermis was identified by the PAS staining. Fibrovascular stroma of the mass was also stained blue with Masson's trichrome. Based on histopathological and histochemical findings, the masses were diagnosed as infiltrative type of basal cell carcinoma (BCC).

Stromal α-Smooth Muscle Actin Positivity Is Associated With High-Risk Basal Cell Carcinomas

ABSTRACT

The presence of myofibroblast differentiation has been proposed as an invading mechanism in basal cell carcinomas. However, small studies regarding α-smooth muscle actin positivity have led to conflicting results. This review of 100 cases examines the association between α-smooth muscle actin positivity on immunohistochemical studies and the clinical and histopathological characteristics of the tumor, including tumor size, thickness, subtype, topography, ulceration, 5-year recurrence rate, and age at diagnosis.

Analysis of the occurrence and distribution of primary and recurrent basal cell carcinoma of head and neck coupled to the assessment of tumor microenvironment and Sonic hedgehog signaling

Often, basal cell carcinoma (BCC) displays local aggressiveness, and when developed in the head and neck presents with deep tissue invasion and recurrence. Previous studies have pointed out the necessity of systematic assessment of primary and recurrent BCC based on a better understanding of the biology and function of its microenvironment. Although hedgehog-dependent tumor cells signaling to the underlying stroma, and vice versa, have been demonstrated to be implicated in the pathogenesis of BCC, little is known about peculiarities of the tumor microenvironment and the above-mentioned signaling in the head and neck. The occurrence and distribution of 79 primary and recurrent BCCs developed in the head and neck region were estimated. The data were coupled with the immunohistochemical assessment of type IV collagen, laminin, alpha-smooth muscle actin (α-SMA), and Sonic hedgehog (Shh). The frequency of the mixed BCCs and the predominance of the nose and cheek region affection by primary and recurrent tumors were demonstrated. Furthermore, the increase of peritumoral and entire stromal α-SMA immunoreactivity in the mixed recurrent BCC was confirmed using statistics. We found the increase of strong levels of Shh immunoexpression in the aggressive variants of BCC - infiltrative, mixed, and micronodular. Surprisingly, we confirmed the upregulation of Shh paralleled by the downregulation of α-SMA immunoexpression in the superficial subtype of the tumor. Our results suggest the necessity of further studies assessing the nature of the tumor along with the peculiarities of signaling in BCCs of head and neck.

Cytokeratin 20-negative Merkel cell carcinoma is infrequently associated with the Merkel cell polyomavirus

Merkel cell carcinoma is a rare, highly aggressive cutaneous neuroendocrine carcinoma most commonly seen in sun-damaged skin. Histologically, the tumor consists of primitive round cells with fine chromatin and numerous mitoses. Immunohistochemical stains demonstrate expression of neuroendocrine markers. In addition, cytokeratin 20 (CK20) is expressed in ∼95% of cases. In 2008, Merkel cell carcinoma was shown to be associated with a virus now known as Merkel cell polyomavirus in ∼80% of cases. Prognostic and mechanistic differences between Merkel cell polyomavirus-positive and Merkel cell polyomavirus-negative Merkel cell carcinoma may exist. There has been the suggestion that CK20-negative Merkel cell carcinomas less frequently harbor Merkel cell polyomavirus, but a systematic investigation for Merkel cell polyomavirus incidence in CK20-negative Merkel cell carcinoma has not been done. To test the hypothesis that Merkel cell polyomavirus is less frequently associated with CK20-negative Merkel cell carcinoma, we investigated 13 CK20-negative Merkel cell carcinomas from the files of the Cleveland Clinic and the University of Michigan for the virus. The presence or absence of Merkel cell polyomavirus was determined by quantitative PCR performed for Large T and small T antigens, with sequencing of PCR products to confirm the presence of Merkel cell polyomavirus. Ten of these (77%) were negative for Merkel cell polyomavirus and three (23%) were positive for Merkel cell polyomavirus. Merkel cell polyomavirus is less common in CK20-negative Merkel cell carcinoma. Larger series and clinical follow-up may help to determine whether CK20-negative Merkel cell carcinoma is mechanistically and prognostically unique.