Basosquamous Carcinoma: Comprehensive Clinical and Histopathological Aspects, Novel Imaging Tools, and Therapeutic Approaches.

Basosquamous carcinoma (BSC), an uncommon and aggressive nonmelanoma skin cancer exhibiting characteristics ranging from basal cell carcinoma (BCC) to squamous cell carcinoma (SCC), is a subject of controversy in terms of its classification, pathogenesis, histologic morphology, biologic behavior, prognosis, and management. This narrative review is based on an electronic search of English-language articles in PubMed that included the terms "basosquamous carcinoma" and/or "metatypical carcinoma of the skin" in their titles. The review aims to succinctly present and assess current data on the epidemiology, clinical presentation, dermoscopic, LC-OCT, and histopathologic characteristics, as well as the genetics and management of BSC, providing insight into this intriguing entity. As a conclusion, dermoscopy, deep incisional biopsies, and immunohistologic techniques should be applied in clinically suspicious lesions to achieve an early diagnosis and better prognosis of this tumor. Surgical treatments, including wide excision and Mohs' micrographic surgery, remain the treatment of choice. Finally, Hedgehog pathway inhibitors and checkpoint inhibitors, must be thoroughly investigated with large controlled trials, since they may offer an alternative solution to irresectable or difficult-to-treat locally advanced cases of basosquamous carcinoma.

HeberFERON en el tratamiento del carcinoma basoescamoso / HeberFERON in Treating Basosquamous Carcinoma

Introducción: El carcinoma basoescamoso es un subtipo agresivo de carcinoma basocelular compuesto por células basaloides y áreas de células escamosas con una zona de transición intermedia, con tendencia a la recurrencia y metástasis. Objetivo: Describir el caso clínico de una paciente con un carcinoma basoescamoso en región temporal cerca del canto externo del ojo izquierdo. Presentación de caso: Se presentó el caso de una paciente con un carcinoma basoescamoso en región temporal cerca del canto externo del ojo izquierdo de 30 mm de diámetro. Se aplicó HeberFERON con respuesta completa al eliminar el tumor. Conclusiones: El HeberFERON es una opción no quirúrgica de tratamiento que puede ser usada en el carcinoma basoescamoso de localización facial que por su tamaño puede provocar mutilaciones o deformidades en esta zona(AU)

Introduction: Basal squamous cell carcinoma is an aggressive subtype of basal cell carcinoma composed of basaloid cells and areas of squamous cells with an intermediate transition zone, with a tendency to recur and metastasize. Objective: To describe the clinical case of a patient with a basal squamous cell carcinoma in the temporal region near the external canthus of the left eye. Case report: This paper reports a case of a female patient with a basal squamous cell carcinoma in the temporal region near the external canthus of her left eye with 30 mm diameter. HeberFERON was used with complete response when eliminating the tumor. Conclusions: HeberFERON is a non-surgical treatment option that can be used in facial basal squamous cell carcinoma that, due to its size, can cause mutilations or deformities in this area(AU)

Complete response of a large basosquamous carcinoma following treatment with cemiplimab and vismodegib.

The anti-PD-1 antibody cemiplimab has demonstrated effectiveness in the setting of locally advanced basal cell carcinoma (BCC) and squamous cell carcinoma. We describe a case of a large, locally invasive basosquamous carcinoma, an aggressive type of BCC, invading the left sternocleidomastoid muscle with near compression of the left internal jugular vein producing a severe anaemia secondary to ulceration and chronic blood loss. The patient was initially started on vismodegib monotherapy but failed to respond. He was then started on cemiplimab in addition to vismodegib. Improvement was noted after one cycle. After 21 cycles of cemiplimab, the left shoulder ulcerated lesion was completely re-epithelialised. He remains in complete remission after 31 cycles of cemiplimab in addition to vismodegib.

Metastasis of a basosquamous carcinoma arising in a nevus sebaceus.

Nevus sebaceus (NS) is a congenital hamartoma of skin structures including the epidermis, sweat sebaceous glands, and hair follicles. It is known that secondary tumors can occur in NS. However, secondary metastatic malignancies are rare. Basosquamous carcinoma (BSC) is an aggressive type of basal cell carcinoma (BCC) characterized by squamous differentiation. Herein, we report a case of metastatic BSC that developed in a 73-year-old male with NS. The clinical presentation of this patient was that of an ulcerative nodule developing in a longstanding plaque-like lesion consistent with NS. Histopathological examination revealed characteristic features of BCC with some areas of squamous differentiation in addition to the structure of a typical NS. Immunohistochemical expression of Ber-EP4, AE1/AE3, and epithelial membrane antigen helped to make the diagnosis of BSC.

Case Report: Basaloid Squamous Cell Carcinoma of the Tongue: A Case Report.

Basaloid squamous cell carcinoma (BSCC) is a rare variant of conventional squamous cell carcinoma (SCC) frequently affecting the upper aerodigestive tract. The hypopharynx, tonsil, supraglottic larynx, tongue (base), and head-neck regions are particularly susceptible to BSCC. Clinically, the presentation of BSCC and conventional SCC is similar, but BSCC has a poorer prognosis. BSCC is distinguished histopathologically by a dimorphic pattern, a distinctive basal cell component paired with a squamous component. However, its similar features to conventional SCC makes it difficult to diagnose. Therefore, histopathology and immunohistochemistry play a crucial role in diagnosing such tumors. Here we present the case of a 70-year-old male diagnosed with BSCC involving the tongue.

Line-field confocal optical coherence tomography of basosquamous carcinoma: a case series with histopathological correlation.

BACKGROUND: Basosquamous carcinoma (BSC) is a rare and potentially aggressive cutaneous neoplasm combining histopathological features of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Line-field confocal optical coherence tomography (LC-OCT) is a new, non-invasive imaging technique featuring excellent resolution and penetration. To date, studies about the use of LC-OCT in the BCC and SCC fields are available, but similar investigations are lacking in the BSC field. OBJECTIVE: The goal of the present study was to identify/describe LC-OCT criteria of BSC. METHODS: Consecutively enrolled BSCs were imaged with dermoscopy and LC-OCT prior to surgical excision. Dermoscopic and LC-OCT images were evaluated, and histopathological slides were reviewed. RESULTS: Six BSCs from six patients [four (66.7%) males and two (33.3%) females; mean age 76.5 (62-96) years] were included. Identified LC-OCT criteria for BSC included BCC-associated (dermal lobules with millefeuille pattern, dilated vessels, bright cells within the epidermis, bright cells within lobules, stromal stretching, stromal brightness) and SCC-associated features (acanthosis, hyperkeratosis, disarranged epidermal architecture, broad strands, elastosis and glomerular vessels). Interruption of the dermal-epidermal junction and ulceration represented overlapping criteria. CONCLUSION: Line-field confocal-OCT is a new promising technique that may support the non-invasive recognition of BSC through the simultaneous detection of BCC-associated and SCC-associated features. We hypothesize that the use of LC-OCT might be helpful not only in the diagnostic setting but also in the follow-up surveillance for an early identification of recurrences. Further larger studies are needed to prove this hypothesis.

How to spot a basosquamous carcinoma: a study on demographics, clinical-dermatoscopic features and histopathological correlations.

Basosquamous carcinoma (BSC) is a relatively rare type of neoplasm originating from basal cell carcinoma with features of squamous differentiation. BSC has an aggressive local behaviour with a tendency for recurrence and a less frequent metastatic potential The primary objective was to describe the dermatoscopic features of the tumour. Secondary goals were to detect the morphological features of the tumour along with patients' characteristics and to evaluate possible dermatoscopic and histopathological correlations Twenty-two patients with 25 BSCs were enrolled. All tumours were surgically excised and diagnosis was based on histopathology. Clinical and dermatoscopic images were evaluated by two investigators based on pre-defined criteria, and a statistical analysis was performed The median age of the patients was 78 years old (range: 52-88) and the male/female ratio was 2.14. All patients reported history of either occupational (50%) or recreational (50%) intensive sun exposure and 72.73% had signs of actinic keratosis. The most common anatomical site of the tumours was the head/neck area (72%). Clinically, nodular (64%), ulcerated (88%) and non-pigmented (76%) lesions prevailed. Dermatoscopically, 92% had prominent vasculature and monomorphous arborizing vessels with a diffuse arrangement, representing the most frequently observed type. Ulceration (88%), SCC dermatoscopic criteria (56%), white strands/blotches (56%) and features of pigmentation (40%) were also detected We suggest that the most common prototype of BSC is an ulcerated, facial nodule in elderly males with photo-damaged skin, dermatoscopically displaying combined features of mostly nodular BCC and, to a less extent, SCC.

Tumor de colisão basoescamoso na região de sulco nasogeniano direito em mulher de 50 anos: relato de caso / Basoescamous collision tumor in nasolabial groove region in 50-year-old woman: case report / Tumor de colisión basosescamoso en la región del surco nasogeniani derecho en una mujer de 50 años: reporte de caso

Introdução: Tumor de colisão ou tumor misto é uma neoplasia maligna rara de pele, ainda carente de estudos e casos. A histologia dessa lesão é composta pela sobreposição entre os carcinomas basocelular e epidermoide, ou seja, duas neoplasias com histologias distintas e interface nítida entre ambas. Objetivo: Relatar o caso de uma paciente com carcinoma basoescamoso. Material e Método: Estudo de relato de caso de uma paciente do sexo feminino, 50 anos, com lesão única e progressiva na região de sulco nasogeniano direito. Ao Exame físico: lesão de aspecto papular hiperemiado, com centro ulcerado e crosta central milicérica. Dermatoscopia: teleangiectásias encimadas à área e hiperemiadas. Hipótese diagnóstica sugestiva de Carcinoma Basocelular e/ou Carcinoma Espinocelular. O tratamento realizado foi cirúrgico em 2018, com exame histológico demonstrando a presença de carcinoma de células escamosas contíguo ao carcinoma de células basais. Índices de recidiva local variam de 12% a 45% e os principais fatores prognósticos são o tempo de diagnóstico, margens cirúrgicas, infiltração perineural, órbita ocular, cerebral e cavidade nasal. A paciente, em 2021 evoluiu com uma pápula rósea na mesma região, sulco nasogeniano direito, constituindo uma crosta intermitente, sendo realizada uma ampliação de margem cirúrgica de 0,7cm, e encaminhamento para anatomopatológico detectando-se um pequeno nilho de células basaloides em meio a fibrose dérmica cicatricial. Conclusão: Condição rara, o carcinoma basoescamoso requer diagnóstico diferencial, definido através de critérios histológicos distintos, pois ambas as neoplasias apresentam comportamento clínico semelhante. Tratamento de escolha: ressecção, sendo exérese da lesão com margem livre de segurança ou a micrografia de Mohs as mais indicadas, pode-se associar radioterapia na sua adjuvância, desde que não provoque radiodermite e radionecrose como efeitos adversos.(AU)

Introduction: Collision tumor or mixed tumor is a rare malignant skin neoplasm, still lacking studies and cases. The histology of this lesion is composed by the overlap between basal cell and epidermoid carcinomas, that is, two neoplasms with distinct histologies and a clear interface between both. Objective: To report the case of a patient with basal squamous carcinoma. Material and Method: A case report study of a 50-year-old female patient with a single progressive lesion in the right nasolabial sulcus region. At the physical examination: lesion of hyperemiated papular aspect, with ulcerated center and milicérica central crust. Dermatoscopy: teleangiectasias surmounted to the area and hyperemiadas. Diagnostic hypothesis suggestive of Basal Cell Carcinoma and/or Squamous Cell Carcinoma. The treatment was surgical in 2018, with histological examination demonstrating the presence of squamous cell carcinoma adjacent to basal cell carcinoma. Local recurrence rates range from 12% to 45% and the main prognostic factors are diagnosis time, surgical margins, perineural infiltration, ocular orbit, cerebral and nasal cavity. The patient, in 2021, evolved with a rosy papule in the same region, right nasolabial sulcus, constituting an intermittent crust, being performed a surgical margin enlargement of 0.7cm, and referral for anatomopathological detecting-a small nile of basaloid cells amid cicatricial dermal fibrosis. Conclusion: Rare condition, basal carcinoma requires differential diagnosis, defined by different histological criteria, because both neoplasms present similar clinical behavior. Treatment of choice: resection, since excision of the lesion with a margin of safety or Mohs micrograph are the most indicated, radiotherapy can be associated in its adjuvant, provided it does not cause radiodermitis and radionecrosis as adverse effects.(AU)

Introducción: El tumor de colisión o tumor mixto es una neoplasia maligna rara de la piel, aún carente de estudios y casos. La histología de esta lesión está compuesta por la superposición entre carcinomas de células basales y de células escamosas, es decir, dos neoplasias con histologías distintas y una interfaz clara entre ellas. Objetivo: Reportar el caso de un paciente con carcinoma escamoso basal. Material y Método: Estudio de reporte de caso de una paciente de 50 años de edad con lesión única y progresiva en la región del surco nasolabial derecho. Al examen físico: lesión papular hiperémica con centro ulcerado y costra central milicérica. Dermatoscopia: telangiectasias por encima de la zona e hiperémica. Hipótesis diagnóstica sugestiva de Carcinoma de Células Basocelulares y/o Carcinoma de Células Escamosas. El tratamiento realizado fue quirúrgico en 2018, con examen histológico demostrando la presencia de carcinoma epidermoide contiguo a carcinoma basocelular. Las tasas de recurrencia local oscilan entre el 12% y el 45% y los principales factores pronósticos son el tiempo hasta el diagnóstico, los márgenes quirúrgicos, la infiltración perineural, la órbita ocular, el cerebro y la cavidad nasal. En 2021, el paciente evolucionó con una pápula rosada en la misma región, surco nasolabial derecho, constituyendo una costra intermitente, fibrosis dérmica cicatricial. Conclusión: Una condición rara, el carcinoma basoescamoso requiere un diagnóstico diferencial, definido a través de diferentes criterios histológicos, ya que ambas neoplasias tienen un comportamiento clínico similar. Tratamiento de elección: resección, con escisión de la lesión con margen libre de seguridad o micrografía de Mohs como los más indicados, se puede asociar radioterapia en su coadyuvante, siempre que no provoque radiodermitis y radionecrosis como efectos adversos.(AU)

Preferentially expressed antigen in melanoma expression in nonmelanoma skin cancers and melanocytes in surrounding skin.

BACKGROUND: Immunohistochemistry for preferentially expressed antigen in melanoma (PRAME) has been studied in melanocytic lesions but not nonmelanoma skin cancers (NMSCs). This study evaluated PRAME expression in NMSCs and dermoepidermal junction (DEJ) melanocytes in the surrounding skin. METHODS: Ninety-nine NMSCs were studied: 23 Merkel cell carcinomas (MCCs), 25 well to poorly differentiated squamous cell carcinomas (SCCs), 14 basal cell carcinomas (BCCs), five basosquamous carcinomas, four sebaceous carcinomas, ten atypical fibroxanthomas, 11 dermatofibrosarcoma protuberans, and seven leiomyosarcomas. Staining quality was considered low or high intensity. Staining quantity was reported as negative 0%, 1% to 24%, 25% to 50%, and >50%. DEJ melanocyte PRAME expression was recorded. RESULTS: Forty-eight percent of NMSCs showed PRAME expression, mostly low intensity in fewer than 25% of cells. High-intensity expression was noted in one poorly differentiated SCC, six BCCs, and seven MCCs. Only MCCs showed expression in greater than 25% of tumor cells. Focal DEJ melanocytes expressed high-intensity PRAME in 18% of cases, most commonly SCCs (11/23). CONCLUSIONS: PRAME is negative or expressed with low intensity in a small percentage of NMSCs, with the exception of some MCC showing high-intensity and diffuse staining. Focal DEJ melanocytes showed high-intensity PRAME reactivity in the skin surrounding some NMSCs.

Skin tumors in xeroderma pigmentosum: Evaluation of a large series and a literature review.

BACKGROUND: Xeroderma pigmentosum (XP) is a rare genodermatosis with a lifelong propensity to develop malignant skin tumors. METHODS: In this retrospective study, 24 XP patients were evaluated with regard to frequency and clinicopathological features of benign and malignant skin tumors. RESULTS: Seventeen patients had at least one malignant skin tumor diagnosed: basal cell carcinoma (BCC) in 13 patients (n = 72), basosquamous carcinoma in three patients (n = 4), squamous cell carcinoma in six patients (n = 13), keratoacanthoma in three patients (n = 15), and melanoma in six patients (n = 18). Most melanomas (n = 15) were in situ lesions. Several benign skin tumors were noted such as tricholemmoma (n = 1), trichoepithelioma (n = 1), trichoblastoma (n = 1), follicular infundibulum tumor (n = 1), keratoacanthoma-like follicular lesion (n = 1), adnexal tumors with folliculosebaceous (n = 1) and tricholemmal differentiation (n = 1), and neurofibroma (n = 1). Benign vascular proliferations including pyogenic granulomas (n = 8), widespread telangiectasias, and senile angioma-like lesions were also observed in 3, 5, and 5 patients, respectively. CONCLUSIONS: Similar to many reports, BCC was found to be the most common malignant skin tumor. The high prevalence of benign adnexal tumors of follicular differentiation, some of them showing mixed histopathological features and various vascular proliferations in our series raises the question of whether they indicate a formerly undescribed association with XP.

Characterization of Basosquamous Cell Carcinoma: A Distinct Type of Keratinizing Tumour.

Basosquamous carcinoma is a rare clinical entity, which comprises 1.7-2.7% of all skin carcinomas. It is described as a basal cell carcinoma with features of squamous differentiation. To date, studies of the epidemiology of basosquamous carcinoma have been few and small in size. We report here the most extensive series of basosquamous carcinomas published to date, highlighting the differences between basosquamous carcinoma and other keratinizing tumours. Patients undergoing surgical excision for keratinizing tumours were enrolled in this study. Age, sex and tumour characteristics were recorded. A total of 1,519 squamous cell carcinomas, 288 basosquamous carcinomas and 4,235 basal cell carcinomas were collected. Basosquamous features were compared with those of basal cell and squamous cell carcinomas. For basosquamous carcinomas, 70.5% were located on the head and neck, particularly on the nose, forehead and cheeks, and represented almost 10% of the keratinizing tumours on the ears. Significant differences were found between basosquamous carcinoma and basal cell or squamous cell carcinomas. Basosquamous carcinoma should be considered a distinct type of keratinizing tumour with different anatomical, sex and age distributions.

Clinical and epidemiological analysis of basosquamous carcinoma: results of the multicenter study.

Basosquamous carcinoma (BSC) is a rare non-melanoma skin cancer that shares the characteristic features of both basal and squamous cell carcinomas (BCC, SCC). Our research enables better characterization of BSC in comparison to high-risk subtypes of BCC and SCC. Paper includes a retrospective analysis of BSC cases regarding sex, age, number of tumors and anatomical distribution in comparison to BCC and SCC evaluating the differences and defining the implications. Histologically confirmed carcinomas recorded between 1999 and 2019 were studied. 181 diagnosed BSC cases were identified, making this study the largest cohorts of BSC patients reported worldwide. Most cases were reported on head and neck. Analysis of facial anatomic distribution shows that most commonly affected sites were the nose (43%) and the cheek (25%). The age at excision of metatypical BCC was higher than those of low-risk BCC (P < 0.05), however similar to high-risk BCC (P = 0.20). We revisited that the concept of BSC is the most similar to high-risk subtypes of BCC. Patients with diagnosed BSC have higher risk of second nonmelanoma skin cancer. Therefore, the frequency of follow-up examination should be adjusted to the individual risk of another skin cancer.