Basaloid squamous cell carcinoma of the maxillary sinus: Report of two cases in association with cathepsin K expression

Successful Treatment of Basaloid Squamous Cell Carcinoma of the Nasal Cavity With Brain Invasion

Basaloid squamous cell carcinoma (BSCC) is a rare and aggressive subtype of squamous cell carcinoma (SCC). To date, no consensus on the treatment of BSCC has been established yet, especially in cases of invasion of the skull base. In addition, long-term prognosis has not been reported in T4b cases. Herein, we report the case of a 36-year-old Japanese man with locally advanced nasal BSCC that directly invaded the skull base and the brain. The patient was then treated with induction chemotherapy (IC). Owing to his good response to IC, we planned and performed en bloc resection followed by adjuvant proton beam therapy (PBT). Follow-up examinations five years after treatment showed no evidence of recurrence. This is the first report of IC followed by radical surgery and adjuvant PBT in a patient with T4b. IC has the potential to play an important role in treatment strategies.

Analysis of Human Papillomavirus (HPV) and Polyomaviruses (HPyVs) in Adenoid Cystic Carcinoma (AdCC) of the Head and Neck Region Reveals Three HPV-Positive Cases with Adenoid Cystic-like Features

An aetiological role of human papillomavirus (HPV) and/or human polyomaviruses (HPyVs) has been proposed in adenoid cystic carcinoma (AdCC). Moreover, HPV-related multiphenotypic carcinoma (HMSC) was recently introduced as an emerging entity of the sinonasal region. Here, we primarily want to study the role of HPV/HPyV in a large AdCC cohort and, secondly, possibly identify and characterize HMSC. Tumour DNA from 68 patients initially diagnosed with AdCC between 2000 and 2012 was, therefore, tested for 27 HPV types and 10 HPyVs. HPV DNA-positive samples were micromorphologically re-evaluated, further stained for p16^INK4a, S100, p63 and CD117 and tested for the presence of the MYB-NFIB fusion transcript. Notably, no samples were HPyV-positive, while one sinonasal and two tonsillar carcinomas were HPV- and p16-positive. After re-evaluating the micromorphology, immunohistochemistry and presence of fusion transcripts, all tumours had the same appearance and fitted within the diagnosis of HMSC, but in all these three cases, the morphology of the HMSC and basaloid squamous cell carcinoma was overlapping. We conclude that HPV and HPyV have no major role in AdCC. However, based on our data, we also suggest that HMSC should be considered as a basaloid variant of squamous cell carcinoma, and not its own entity, until better characterized.

Human Papillomavirus-Related Multiphenotypic Sinonasal Carcinoma-An Even Broader Tumor Entity?

Human papillomavirus (HPV)-related multiphenotypic sinonasal carcinoma (HMSC) is a recently defined tumor subtype with apparent favorable clinical outcome despite aggressive histomorphology. However, in recent years, additional numbers of cases, with more variable features and at locations outside the sinonasal region, have complicated the definition of HMSC. Here, we have performed a systematic review of all cases described so far in order to accumulate more knowledge. We identified 127 articles published between 2013 and 2021, of which 21 presented unique cases. In total, 79 unique patient cases were identified and their clinical and micromorphological nature are herein summarized. In our opinion, better clinical follow-up data and a more detailed tumor characterization are preferably needed before HMSC can finally be justified as its own tumor entity.

Distribution of Cathepsin K in Late Stage of Tooth Germ Development and Its Function in Degrading Enamel Matrix Proteins in Mouse

Cathepsin K (CTSK) is a member of cysteine proteinase family, and is predominantly expressed in osteoclastsfor degradationof bone matrix proteins. Given the similarity in physical properties of bone and dental mineralized tissues, including enamel, dentin and cementum, CTSK is likely to take part in mineralization process during odontogenesis. On the other hand, patients with pycnodysostosis caused by mutations of the CTSK gene displayedmultipledental abnormalities, such as hypoplasia of the enamel, obliterated pulp chambers, hypercementosis and periodontal disease. Thereforeitis necessary to study the metabolic role of CTSK in tooth matrix proteins. In this study, BALB/c mice at embryonic day 18 (E18), post-natal day 1 (P1), P5, P10 and P20 were used (5 mice at each time point)for systematic analyses of CTSK expression in the late stage of tooth germ development. We found that CTSK was abundantly expressed in the ameloblasts during secretory and maturation stages (P5 and P10) by immunohistochemistry stainings.During dentinogenesis, the staining was also intense in the mineralization stage (P5 and P10),but not detectable in the early stage of dentin formation (P1) and after tooth eruption (P20).Furthermore, through zymography and digestion test in vitro, CTSK was proved to be capable of hydrolyzing Emdogain and also cleaving Amelogenininto multiple products. Our resultsshed lights on revealing new functions of CTSK and pathogenesis of pycnodysostosis in oral tissues.

Basaloid squamous cell carcinoma of the sinonasal tract with metastasis to the liver: a case report and literature review

Basaloid squamous cell carcinoma (BSCC) is a rare subtype of squamous cell carcinoma. To date, only 95 cases of sinonasal BSCC have been reported in the English-language literature, and they account for 5% of all cases of head and neck BSCC. We describe what we believe is only the second reported case of a sinonasal tract BSCC that metastasized to the liver. The patient was a 36-year-old woman who presented with right-sided nasal obstruction and a foul-smelling discharge. Clinical examination and imaging identified a large, lobulated, enhancing mass in the right nasal cavity. Following excision of the mass, the patient was scheduled for radiotherapy. However, before it could be administered, follow-up imaging detected a metastasis to the liver and lung, and the patient was switched to chemotherapy. Initially, she responded well clinically, but at 5 months postoperatively, a follow-up CT showed an increasing metastatic presence in the liver and bone. The patient died of her disease 1 year after surgery.

Basaloid Squamous Cell Carcinoma of the Ethmoid Sinus with Invasion into the Skull Base Treated with Craniofacial Resection and Adjuvant Intensity-Modulated Radiation Therapy: A Case Report

Basaloid squamous cell carcinoma (BSCC) is a rare variant of squamous cell carcinoma (SCC), which is highly aggressive, with a tendency for multifocality, local invasion, and with a high metastatic potential. Less than forty cases of BSCC of the sinonasal tract have been reported in the literature, and no reports were found on sinonasal BSCC arising from the ethmoid sinus. We report the case of a 78-year-old man who presented with BSCC arising from the ethmoid sinus with extensive bone destruction and intracranial extension. He was treated with craniofacial resection followed by adjuvant intensity-modulated radiation therapy to the tumor bed (60 Gy in 30 fractions), and the upper neck lymph nodes (50 Gy in 25 fractions). At the patient’s last follow-up, four months after diagnosis, there was no evidence of disease. Aggressive management using craniofacial resection followed by adjuvant radiation therapy with or without radiosensitizing chemotherapy seems to be a reasonable approach to this challenging disease.

The role of cathepsin K in oral and maxillofacial disorders

Cathepsin K (CTSK) was thought to be a collagenase, specifically expressed by osteoclasts, and played an important role in bone resorption. However, more and more research found that CTSK was expressed in more extensive cells, tissues, and organs. It may not only participate in regulating human physiological activity, but also be closely related to a variety of disease. In this review, we highlight the relationship between CTSK and oral and maxillofacial disorders on the following three aspects: oral and maxillofacial abnormities in patients with pycnodysostosis caused by CTSK mutations, oral and maxillofacial abnormities in Ctsk(-/-) mice, and the role of CTSK in oral and maxillofacial diseases, including periodontitis, peri-implantitis, tooth movement, oral and maxillofacial tumor, root resorption, and periapical disease.

Basaloid squamous cell carcinoma of the maxilla

Basaloid squamous cell carcinoma (BSCC) is a distinctive aggressive variant of squamous cell carcinoma. We present a case of a 60-year-old man with tender swelling in the right cheek region for 6 months and continuous unilateral nasal discharge for 2 months. Extraoral examination revealed an ovoid, well-defined swelling from the right infraorbital rim to the angle of the mouth superoinferiorly and the right lateral wall of the nose to preauricular region anteroposteriorly. Intraorally, an ulceroproliferative growth from right upper gingivobuccal sulcus to mid palatine raphe with bicortical expansion was evident. CT revealed a hypodense mass obliterating the right maxillary sinus. Histopathology showed closely packed basaloid cells, with hyperchromatic palisading nuclei, arranged in a solid pattern with a lobular configuration. Prominent areas of comedo necrosis and keratin pearl formation were seen. These features suggested BSCC. The patient underwent surgical excision with adjuvant radiation but was lost to follow-up after 6 months of radiation therapy.