Individual Cell Keratinization Research Articles

First reported case of thymoma-associated multiorgan autoimmunity induced by COVID-19.

Thymoma-associated multiorgan autoimmunity (TAMA) presents with skin symptoms similar to those of graft-versus-host disease (GVHD), liver dysfunction, and enteritis, in the absence of a history of hematopoietic stem cell or bone marrow transplantation. TAMA is a type of paraneoplastic syndrome associated with thymoma. Its etiology is unclear but is thought to be a result of breakdown of immune tolerance. Histopathologically, TAMA is characterized by epidermal acanthosis with parakeratosis, individual cell keratinization, liquefaction degeneration, and intraepidermal infiltration of CD8-positive lymphocytes. A 64-year-old female patient with a history of myasthenia gravis and thymoma treated with prednisolone (10 mg/day) and cyclosporine (150 mg/day) experienced erythema on her trunk after coronavirus disease 2019 (COVID-19) onset. A psoriatic drug eruption was suspected and the possible causative drug was discontinued, but the skin rash failed to improve. A skin biopsy demonstrated GVHD-like histopathological findings. Diarrhea, abdominal pain, and duodenal perforation occurred concurrently, leading to the diagnosis of TAMA. Thereafter, the patient continued prednisolone and cyclosporine in the same doses as the TAMA treatment and added topical steroids. During the disease course, candida fungemia and cytomegalovirus infection developed, resulting in the patient's death. The TAMA was considered to have been caused by the release of inflammatory cytokines, autoreactive T cell activation, and regulatory T cell dysfunction induced by COVID-19.

Exuberant individual cell keratinization: An unusual presentation in oral squamous cell carcinoma

Exuberant individual cell keratinization: An unusual presentation in oral squamous cell carcinoma

Diltiazem-associated, photo-distributed hyperpigmentation in a patient with Sjögren’s syndrome

Sir, Herein, we report a case of hyperpigmented macules on ultraviolet exposed areas during the intake of diltiazem hydrochloride (DTH) in a patient with Sjögren’s syndrome. A 63-year-old Japanese female with a history of Sjögren’s syndrome and vasospastic angina presented to our hospital with brown, irregular macules on the neck, face, and both hands, which she first noticed one year earlier. The patient had a history of taking DTH for vasospastic angina for the previous fifteen years. A physical examination revealed pale brown macules and plaques irregularly scattered around the corners of the mouth, lower lip, and neck (Figs. 1a and 1b). In addition, there were numerous erythematous papules on the dorsal side of both hands. The oral mucosal membrane, scalp, and nails were not involved. A biopsy specimen taken from the dorsal side of a hand revealed individual cell keratinization in the epidermis, intercellular edema, liquefaction degeneration of the basal layer, and band-like lymphocyte infiltrate with melanophages in the superficial dermis (Fig. 2a). Immunohistochemistry revealed the infiltration of CD3+, CD4+, CD8+, and HLA-DR+ lymphocytes in the superficial dermis (Figs. 2b and 2c). Routine laboratory examinations of the blood cell count, serum, and urine showed no abnormalities. Other tests showed positive antinuclear antibody (1:80, nucleolar) and anti-SS-A antibody (240 U/mL; normal: < 9.9), whereas hepatitis C virus antibody, rheumatoid factor, anti-CCP antibody, and anti-SS-B antibody were negative. DTH was switched to another medicine, and ascorbic acid, calcium pantothenate, and topical steroids were initiated. In addition, we advised the patient to avoid sun exposure. Although no improvement was observed in the rash in the first four months, it disappeared at follow-up several years later (Figs. 3a and 3b).

Bowen disease on the dorsum of the foot associated with human papillomavirus type 16

A 94 years old Japanese female was presented to our hospital with a skin lesion on her left foot. A physical examination found a markedly hyperkeratotic reddish-brown plaque, measuring 3 cm in diameter. A biopsy specimen showed prominent papillomatosis, hyperkeratosis, and atypical keratinocytes throughout the epidermis. Individual cell keratinization, multinucleated keratinocytes, and many keratinocytes with clear cytoplasm were seen. We excised the lesion, and the skin grafting was used for covering the skin defect. We investigated whether human papillomavirus (HPV) was present in the lesion, and HPV 16 DNA was detected using the polymerase chain reaction. Immunohistochemical analysis showed several HPV-positive cells in the upper epidermis. In addition, the tumor cells showed strong and diffuse expression of p16INK4a. Bowen disease (BD) is an intraepidermal squamous cell carcinoma. The precise pathogenesis of BD is unclear, but it involves various factors. HPV infection is one of these factors and is a well-known cause of BD of the genitalia and fingers. It has been shown that some BD lesions occurring at other locations are also associated with HPV. Dysregulation of the Rb/p16INK4a pathway is considered to play an important role in HPV-induced BD, but the precise mechanism remains to be elucidated. J. Med. Invest. 69 : 152-154, February, 2022.

Comparisons of histological features among primary oral squamous cell carcinomas before and after adjuvant chemotherapy and their lymph node metastatic cancer lesions after adjuvant chemotherapy

Background/purposeAdjuvant chemotherapy has been used to control the primary oral squamous cell carcinoma (OSCC) size prior to surgical excision of the cancer. This study aimed to explore the histological changes of primary OSCCs and their cervical lymph node metastatic cancer lesions after chemotherapy. Materials and methodsThirty-three OSCC patients with eleven having cervical lymph node metastases received adjuvant chemotherapy before surgical excision of their cancer lesions. Hematoxylin and eosin-stained tissue sections of incisional biopsy, surgical excision, and cervical lymph node metastatic cancer lesion specimens were compared microscopically to observe the histological changes in the cancer tissues after chemotherapy. ResultsCommon histological features could be found in the primary OSCCs and their cervical lymph node metastatic cancer lesions after chemotherapy. These included direct killing of cancer cells by chemotherapeutic agents, resulting in cancer cell necrosis and degeneration in the early phase, and squamous and keratinizing metaplasia of drug-induced cancer cells, leading to individual cell keratinization and keratin pearl formation in the later phase. There were also small nests of drug-resistant proliferating cancer cells in the inflamed fibrous connective tissue stroma. The most characteristic histological feature in the metastatic lymph nodes after chemotherapy was the keratinizing metaplasia of the metastatic cancer cells, resulting in the formation of epidermoid cyst-like lesions. ConclusionAlthough the cancer reduces its size after chemotherapy, residual cancer cells are consistently present in the primary OSCC lesions after chemotherapy. Therefore, wide surgical resection of the cancer is still needed to ensure the complete removal of all cancer tissues.

VERRUCOUS SQUAMOUS CELL CARCINOMA IN THE LOWER LIP: A CASE REPORT

Verrucous squamous cell carcinoma is generally a less aggressive subtype of squamous cell carcinoma. It is most common among male patients, especially affecting the intraoral tissues. A 49-year-old male patient, rural worker, was referred to a dental specialty center because of a lesion located in the lower lip evolving within 2 months. Clinical examination showed a ±2-cm painless, hard-to-touch white lesion. No swollen lymph nodes were noticed. An incisional biopsy was performed, and the histopathologic examination revealed sheets of epidermoid cells with discreet pleomorphism, hyperchromasia, altered nuclear-cytoplasm ratio, and a few mitotic figures plus areas showing individual cell keratinization, keratin pearls, and intense deposition of lamellar keratin on the lesion surface, giving it a papillomatous-characteristic look. The diagnosis of verrucous squamous cell carcinoma was established. The patient was referred to oncology and is now waiting for the next phase of treatment.

Squamous Cell Carcinoma in a Pig

Background: Squamous cell carcinoma (SCC) is a malignant neoplasm of epidermal cells that exhibits keratinocyte differentiation. These neoplasms are common in dogs, cats, horses, and cattle, relatively uncommon in sheep, and rarely affect goats and pigs. There are several factors that are associated with the development of SCC, including prolonged exposure to ultraviolet light, lack of pigment in the epidermis, and sparse coating or lack of fur at the affected sites. The aim of this study was to report the occurrence of squamous cell carcinoma in a domestic pig.Case: A surgically removed nodule from the left ear of a female, light-colored, three-year-old pig, which breed was not defined, was submitted for histopathological analysis. The sample was fixed in 10% formalin, analyzed macroscopically, routinely processed for histology, sectioned at five microns and stained with hematoxylin and eosin. Additionally, anticytokeratin (AE1/AE3) and anti-vimentin immunohistochemical assays were performed. All additional information was provided by the animal’s owner. According to the history obtained, the animal belonged to a herd made up of five females and one boar. For four months, multiple nodules started to grow on the outer surface of the pig’s ear and in many occasions exhibited ulceration and bleeding. One of the nodules was submitted for histopathology examination. Macroscopically it measured 3 cm in diameter, had an irregular and ulcerated surface, and a wide base. Cut surface had a firm consistency and whitish color. Microscopic examination revealed proliferation of neoplastic epithelial cells arranged in islands and trabeculae, with slightly eosinophilic cytoplasm, pleomorphic, round, reniform nucleus, with loose chromatin and 1-3 nucleolus. Mitotic figures were infrequent. In the central area of the islands, there was individual cell keratinization. There was a moderate, fibrovascular supporting stroma with intense inflammatory infiltrate composed of lymphocytes, plasma cells and eosinophils. Anti-cytokeratin (AE1/AE3) immunohistochemical assay (IHC) revealed a strong diffuse positive staining on the cytoplasm of tumoral epithelial cells, and anti-vimentin IHC showed positive staining on the supporting tissue cells (fibroblasts and endothelial cells).Discussion: The diagnosis of squamous cell carcinoma in this pig was based on clinical and pathological findings since it was observed proliferation of neoplastic epithelial cells often forming “keratin pearls” and immunohistochemistry positive for cytokeratin was immunostaining in the cytoplasm of tumor cells. Information on the occurrence of SCC in pigs is scarce in the literature, especially in Brazil. In a survey of neoplasms in farm animals in Southern Rio Grande do Sul with cases from 1978 to 2002, neoplasms in pigs represented 0.6% of the diagnoses when compared to the number of neoplasms in cattle and horses. The low number of cases in this species is due to the fact that a large proportion of the population is slaughtered at a young age and therefore the chances to develop neoplasms are lower. The main SCC growth sites include areas deprived of hair, especially in animals with unpigmented skin. In the pig described here, the neoplasm was located on the outer surface of the ear, which was exposed to ultraviolet rays. Granuloma, papilloma, and basal cell tumor should be considered in the list of differential diagnosis when SCC is suspected. Neoplasms in pigs are scarcely reported.Keywords: neoplasm, carcinoma, pig, immunohistochemical.

Recurrent pain and swelling associated with impacted maxillary third molar

A 57-year-old woman reporting intermittent severe pain and swelling for 5 years in the left maxillary jaw was evaluated at the oral and maxillofacial surgery clinic at the University of Detroit Mercy School of Dentistry. The pain intensity had increased markedly in the past 2 to 3months. She had difficulty swallowing and opening her mouth, and a bad odor associated with a bloody mucous discharge. Her medical and surgical history included chronic neck pain, arthritis, degenerative disk disease, choroid cyst, headaches associated with Arnold-Chiari malformation, sinus surgery due to recurrent sinusitis, and an eye surgery for strabismus. Her dental history included periodic pain and soreness associated with impacted tooth no. 16. Her health history included a 40 pack-year smoking history, and at the time of her examination she was smoking 1 pack per day. She denied alcohol or illicit drug use. Extraoral examination identified a nonerythematous, firm swelling on the left side of her face without evidence of lymphadenopathy. On the basis of the long-standing pain and swelling, the difficulty in opening, and the history of surgery in the left maxillary sinus, the decision was made to examine the patient with cone-beam computed tomography (CT). This technique permits a view of the anatomy in 3 planes of space. It also provides a larger field of view than panoramic radiographs, which was especially beneficial due to the unknown position of the left third molar. The cone-beam CT scan revealed diffuse opacification of the left maxillary sinus with destruction of the alveolar process and resorption of the walls of the maxillary sinus. The pathologic alterations extended beyond the field of view, and considering the likely involvement of extra-antral soft tissues it was decided that CT was necessary for complete radiographic visualization of the condition. A bone window axial view of the CT scan revealed the lesion in the left maxillary sinus associated with destruction of the anterior, posterior-lateral, and medial walls of the left maxillary sinus, with extension into the pterygopalatine fossa as well as the buccal and masticator spaces (Figure 1). Soft-tissue sections depicted infiltration of the lesion into the medial and lateral pterygoid muscles, and extension into the nasal fossa (Figure 2) and greater palatine foramen (Figure 3). Destruction of the palate and left maxillary alveolar ridge was also observed (Figure 4). Microscopic examination after an incisional biopsy revealed a proliferation of squamous epithelium. Cells exhibiting increased nuclear-cytoplasmic ratios, pleomorphism, individual cell keratinization, and increased mitotic activity were noted (Figure 5).

Miles to Discover in Histological Grading of Odontogenic Tumours.

Odontogenic tumours (OTs) are lesions of great interest and importance to oral pathologists and maxillofacial surgeons alike, who for several decades have studied, catalogued these lesions and developed modalities for adequate treatment [1]. Ameloblastoma is the most common and most intriguing of all odontogenic tumours. Although benign it is highly polymorphic, due to its ability to undergo various forms of metaplasia. This has given rise to variants of ameloblastoma in which the stimulus for metaplastic change is poorly understood and has been attributed to the multipotentiality of odontogenic epithelium [2]. In the indexed case, 12-year-old boy presented with the complaint of gradually increasing painless growth in lower front teeth region since 8 months. No evident extraoral swelling or asymmetry was noticed. Regional lymph nodes were not clinically palpable and there was no history of trauma to the same site. Intraoral examination revealed approximately a 2.5x4cm, non tender mucosal sessile mass on lingual aspect of anterior mandible extending from central incisor to second premolar on left side obliterating the lower labial vestibule [Table/Fig-1]. [Table/Fig-1]: Intraoral picture reveals a sessile mass on lingual aspect of anterior mandible There was a faintly palpable anterior lingual expansion. The mandibular incisors, canine and premolar of left side were found to be non vital on thermal testing. Orthopantomograph (OPG) revealed a well circumscribed unilocular radiolucency in the anterior mandible extending from 44 to 35 without cortication. Thinning of lower border of mandible was seen. Root resorption of associated teeth due to pressure was evident [Table/Fig-2]. Considering the benign nature of the lesion, its site of occurrence i.e. anterior to first molars and unilocular appearance, central giant cell granuloma was considered as provisional diagnosis and excisional biopsy was done. [Table/Fig-2]: OPG showing a well circumscribed unilocular radiolucency in the anterior mandible with thinning of lower border Histopathological sections of this case showed well encapsulated tumour mass with extensive areas of squamous differentiation and features of plexiform ameloblastoma [Table/Fig-3]. [Table/Fig-3]: Photomicrograph reveals a well encapsulated tumour mass with extensive areas of squamous differentiation mixed with plexiform pattern (H&E, 10X) Few areas showed material secretion in the tumour matrix which were suggestive of calcifying epithelial odontogenic tumour but when stained with Congo red, came out to be negative [3]. Calcifications or even multinucleated giant cells were not evident in the submitted tissue. Keratin pearl formation was not seen but individual cell keratinization and squamous differentiation were evident throughout the stroma. The tumour appeared to be in biphasic pattern where at one end the tumour cells appeared to be stretched out making the intercellular ridges prominent whereas at the other end, tumour showed squamous differentiation, loss of intercellular bridges and cohesive tumour cells arranged in thick sheets [Table/Fig-4]. Tumour cells were positive for cytokeratin whereas surrounding material was negative [Table/Fig-5]. [Table/Fig-4]: Photomicrograph reveals area of cohesive tumour cells with squamous differentiation & loss of intercellular bridges (H&E, 10X) [Table/Fig-5]: Photomicrograph shows cytokeratin positivity in tumour cells (H&E, 10X) After extensive search in literature only three odontogenic tumours which show keratinization or squamous metaplasia were found. Acanthomatous ameloblstoma exhibit squamous metaplasia of stellate reticulum with or without keratin pearl formation [4]. However, in the present case frank keratin or squamous metaplasia was not seen but only squamous differentiation and individual cell keratinization were seen. Squamous odontogenic tumour also shows squamous metaplasia [5] but in the present case tumour was not arranged in follicles as well as material secretion by tumour cells did not appear to be keratin and tumour cells were not flattened squamous or cuboidal arranged in follicles. Keratoameloblastoma is a heterogenous group of odontogenic neoplasms which exhibit keratin formation in the connective tissue stroma [6]. Such frank keratin formation was absent in the present case. The index case is not of intraosseous squamous cell carcinoma as there was no dysplasia and few areas showed frank stellate reticulum like cells. Moreover, the present case is well encapsulated tumour supporting benign nature which is in contradiction to malignancy i.e. squamous cell carcinoma.

Physiologic Behavioural Changes of Precancerous Leukoplakia Cell lines Exerted to Extremely Low Frequency Electric Field

Objectives: Oral galvanism arising from the presence of two different metallic fillings in the mouth that may reach up to 16V/m, induces several changes in oral environment such as gingival swelling and erythema, mucosal pain, lichenoid reactions and leukoplakia. Study design: To investigate in vitro the physiologic reactions of oral leukoplakia caused by electrostatic corrosion potentials, human leukoplakia cell lines (MSK-LEUK1), cultivated in KGM-2 supplemented with bullet kit in 5% CO2 humidified air at 37°C, were exposed to electric field strength of 1-20 V/m for 24 hours in a pseudo realistic apparatus called “Pulse chamber”. Following this, the cells were analysed for proliferation using BrdU assay, and for apoptosis using TUNEL assay. Findings were assessed utilizing fluorescent microscopy. Ultra structural changes were studied by TEM. Data was evaluated statistically using non parametric Chi-square test. Results: Electric field strength of 1-10V/m led to upregulation of cell proliferation rate between 10.64% and 44.06% (p=0.0001). The apoptotic index increased significantly (p=0.0001) from 20.03% at 1V/m to 46.56% at 10V/m. Leukoplakia cells treated with 16V/m show individual cell keratinization. Conclusion: Oral galvanism induces subcellular changes in oral precancerous leukoplakia cells in vitro that resemble some of the histopathologic features of oral squamous cell carcinoma cells in vivo.

Oral squamous cell carcinoma positive for p16/human papilloma virus in post allogeneic stem cell transplantation: 2 cases and review of the literature

Complications of allogeneic hematopoietic stem cell transplantation (allo-HSCT) includes the risk of secondary malignancies. This may be related to mechanisms including radiation and chemotherapy regimens, chronic graft-versus-host disease, inflammation, and prolonged imunosuppression. Oral squamous cell carcinoma (OSCC) is a complication associated with chronic graft-versus-host disease after allo-HSCT. Although human papillomavirus (HPV) is known to be associated with OSCC, the role of HPV in development of OSCC in post-HSCT patients has not been studied. We identified 2 cases of OSCC in allo-HSCT recipients. Both biopsy specimens tested positive for p16(INK4A), a surrogate marker for HPV. We propose that the association of OSCC and HPV in patients after allo-HSCT may not be incidental. Clinical implications of these cases may imply the need for a HPV screening, early intervention, and consideration of anti-HPV vaccination in this population. The effectiveness of such interventions could be validated in a prospective clinical study.

Unusual Atypical Epithelial Proliferation of Unknown Biologic Behavior in a 5-Year-Old Boy

A 5-year-old boy presented clinically with a subgingival supraperiosteal expansile mass associated with the mandibular anterior central incisors. There was no obvious clinical intraosseous involvement. The oral mucosal epithelium did not reveal any clinical changes suggestive of a process originating from the surface. Histopathologic evaluation revealed soft tissue fragments that were surfaced or lined by hyperkeratinizing and acanthotic stratified squamous epithelium exhibiting cytologic variations that include irregular rete pegs, loss of polarity, individual cell keratinization, increased nuclear/cytoplasmic ratio, and prominent nucleoli.

Induction of apoptosis and up-regulation of cellular proliferation in oral leukoplakia cell lines inside electric field

In dentistry, metallic alloys are used for dentures, restorative materials, and orthodontic devices. Electric voltages up to 950 mV may occur between different dental alloys in the oral cavity. This study aimed to investigate physiologic reactions of oral leukoplakia cells in vitro to electric fields. A human leukoplakia cell line (MSK-LEUK1), cultivated in keratinocyte growth medium (KGM-2) supplemented with growth factors in 5% CO(2) humidified air at 37°C, was exposed to electric field strength of 1-20 V/m for 24 hours in a custom-made pulse chamber. The cells were then analyzed for proliferation with the use of BrdU assay and for apoptosis with the use of TUNEL assay. Findings were assessed with the use of fluorescent microscopy. Ultrastructural changes were studied by transmission electron microscopy. Electric field strength of 1-10 V/m led to up-regulation of cell proliferation rate from 10.64% to 44.06% (P = .0001). The apoptotic index increased significantly (P = .0001) from 20.03% at 1 V/m to 46.56% at 10 V/m. Individual cell keratinization was seen in leukoplakia cells treated with 16 V/m. Oral galvanism induces subcellular changes in oral precancer cells in vitro that closely simulate some of the morphologic features of oral squamous cell carcinoma cells in vivo.

Peripheral squamous odontogenic tumor

A case of peripheral squamous odontogenic tumor is described in a 60-year-old female who presented with a sessile growth in the right posterior mandible. Radiographic examination revealed no evidence of a central lesion in bone. With the characteristic histopathological picture of benign-appearing islands of squamous epithelium scattered randomly against a background of mature fibrous connective tissue, the tumor was diagnosed as peripheral squamous odontogenic tumor (PSOT). The epithelial islands showed peripheral cuboidal or flattened cells, microcyst formation, individual cell keratinization, and keratin pearl formation.

A mouse model of basal‐like breast carcinoma with metaplastic elements

Breast cancers arising in carriers of germline BRCA1 mutations frequently have a basal-like phenotype. Basal-like cancers are characterized by high histological grade, central necrotic areas, foci with metaplastic differentiation, lack of hormone receptor and HER2 (ErbB2) expression, and consistent positivity for basal markers, including CK5/6, CK14, and EGFR. We have used germline manipulation to generate a conditional mouse model of Brca1 deficiency. Transgenic expression of Cre recombinase in the mammary gland of these mice results in deletion of exons encoding the C-terminus of Brca1 and leads to tumour formation when combined with heterozygosity for a p53 mutation. Histologically, these mammary gland tumours were characterized by high histological grade, central necrotic areas, and presence of homologous metaplastic elements. These metaplastic elements consisted of neoplastic spindle cells or squamous cell differentiation in the form of keratin pearls or individual cell keratinization. Immunohistochemical analysis revealed expression of basal-like markers in all cases. The tumour phenotype generated in our mouse model was compared with published data on human basal-like breast carcinomas and also with metaplastic breast cancers with a basal-like phenotype; the comparison showed that we have generated a mouse model of basal-like breast cancer, which should prove useful in testing new and targeted treatments for this type of breast cancer.

Mucoepidermoid Carcinoma of the Liver Diagnosed as a Liver Abscess: Report of a Case

Mucoepidermoid carcinoma of the liver is a rare variant of cholangiocarcinoma, containing both mucus-secreting glandular cells and squamous cells mixed in nests. We report a case of mucoepidermoid carcinoma of the liver in a 69-year-old woman who presented with a 1-week history of fever, chills, and right flank pain. On admission, she was not jaundiced, and under a provisional diagnosis of liver abscess, a pigtail catheter was inserted into the abscess cavity. We performed right hepatectomy and partial excision of the diaphragm 1 month later. Microscopically, the tumor was composed of solid and invasive nests of epidermoid and mucin-producing cells with desmoplastic stroma. The epidermoid component of the tumor contained intercellular bridges and individual cell keratinization. Alcian blue and Periodic acid-Schiff (PAS) staining confirmed that there was mucin in the cytoplasm of mucus-secreting cells. The tumor cells, intrahepatic bile ducts, and ductules were consistently reactive with cytokeratin (CK) 7 and negative for CK20. The adjacent nonneoplastic liver cells were CK 7-/CK20-, and P63 immunostaining was positive in the epidermoid cells. The tumor was diagnosed as mucoepidermoid carcinoma arising from the intrahepatic bile duct. Despite aggressive surgical treatment, the patient died of multiple liver metastases 4 months after the right hepatectomy.

Primary Orofacial Squamous Cell Carcinoma: A Multicenter Nigerian Study

BACKGROUND: Previous Nigerian reports of primary orofacial squamous cell carcinoma have focused on individual center experiences; hence we decided to undertake a review of cases in order to give a fairly national overview. METHODS: Multicenter retrospective study of 149 histologically diagnosed cases of primary orofacial squamous cell carcinoma seen between 1992-2001 in 3 Nigerian Teaching Hospitals RESULTS: The patients' (85 males (57%) and 64 (43%) females.) whose ages ranged from 11-91years (mean ± SD; 54 ± 15.5 years, median 52.5 years) constituted 78.7% of all orofacial malignancies seen within the study period. Lesions were of 8-67 weeks duration (mean ± SD 28.6± 15.1 weeks, median 24 weeks). Overall, the maxillary antrum (20.3%) was the most commonest site, while intraorally; the alveolus (29.6%) and palate (12.4%) predominated. Most lesions (65.8%) were welldifferentiated and only 35.6% showed individual cell keratinization. Patients with well-differentiated lesions had a comparatively higher mean age than their counterparts with other histological varieties and this was statistically significant (P < 0.05). About 45.6% presented with stages III and IV disease, and significant difference was found between duration of the lesions and clinical staging of disease (P < 0.05). Surgery in conjunction with radiotherapy was undertaken for 36.9% of the cases, followed by surgery alone in 14.4%. Close to a quarter (24.2%) either declined or failed to turn-up for treatment. Whereas treatment was found to be successful in 13.4% of the cases, failure to attend follow-up appointment was observed in 62.4%. CONCLUSIONS: The pattern of orofacial squamous cell carcinoma differs from that of industrialized countries and since the majority of the lesions were well differentiated, there is need for intensive oral health awareness to encourage early presentation, as this will further enhance prognosis.

Basaloid squamous cell carcinoma of the sinonasal tract

Basaloid squamous cell carcinoma (BSCC) is a high grade, aggressive variant of squamous cell carcinoma with a predilection for the larynx, hypopharynx, tonsils, and base of the tongue. To the authors' knowledge, BSCC originating in the nasal cavity and paranasal sinuses rarely has been reported. Fourteen cases of BSCC involving the nasal cavity and paranasal sinuses were identified in the files of the Otolaryngic-Head and Neck Pathology Tumor Registry of the Armed Forces Institute of Pathology from 1975-1997. Clinical records and follow-up were available in all cases. Paraffin blocks were available for histochemical and immunohistochemical studies in all cases. There were 7 females and 7 males, ages 32-86 years (median, 66.5 years; mean, 62 years). The patients presented primarily with a mass lesion and unilateral nasal obstruction. In nine patients the tumor was confined to the nasal cavity. In three patients the tumor involved the sinuses alone and in two patients the tumor involved the nasal cavity and paranasal sinuses. Histologically, the tumors were widely invasive with a variety of growth patterns, including lobular, solid, trabecular, cribriform, and fascicular. The neoplastic infiltrate included predominantly pleomorphic, basaloid-appearing cells with hyperchromatic nuclei, inconspicuous to prominent nucleoli, and a variable amount of eosinophilic to clear-appearing cytoplasm. Mitotic figures, including atypical forms, were readily apparent as was necrosis (individual cell and comedo-type). Foci of squamous differentiation were limited in extent but were found in all cases and included squamous whorls, individual cell keratinization, and intercellular bridges. Intraepithelial dysplasia, carcinoma in situ, or invasive squamous carcinoma was present in all cases. Other histologic features included intercellular stromal hyalinization and peripheral nuclear palisading. In two cases, neural-type rosettes were found. Immunoreactivity for a variety of epithelial markers including cytokeratin (AE1/AE3/LP34), CAM 5.2, 34betaE12, CK7, and epithelial membrane antigen was present in all cases. Variable reactivity was present with vimentin, actins (smooth muscle and muscle specific), neuron specific enolase, S-100 protein, glial fibrillary acidic protein, CK20, carcinoembryonic antigen, Leu7, and Ewing's marker. Chromogranin, synaptophysin, neurofibrillary protein, leukocyte common antigen, HMB-45, desmin, and Epstein-Barr virus latent membrane protein were absent. Surgical resection was the treatment of choice. Eight patients had recurrent or persistent tumor and metastatic disease occurred in five patients. At last follow-up, 7 patients (50%) had died of disease with a median survival of 12 months from the time of diagnosis and 3 patients were alive with disease over periods ranging from 8 months-5 years. Of the 4 remaining patients, 2 were alive without disease at 1 month and 5 years, respectively, 1 patient was lost to follow-up with no evidence of tumor at 3 years, and 1 patient had died of unrelated causes with no evidence of disease. Sinonasal BSCC is a histologically distinct variant of squamous cell carcinoma with pathologic features and aggressive biologic behavior similar to BSCC localized to more common mucosal sites of the upper aerodigestive tract.

Basaloid squamous cell carcinoma of the sinonasal tract

BACKGROUND. Basaloid squamous cell carcinoma (BSCC) is a high grade, aggressive variant of squamous cell carcinoma with a predilection for the larynx, hypopharynx, tonsils, and base of the tongue. To the authors' knowledge, BSCC originating in the nasal cavity and paranasal sinuses rarely has been reported. METHODS. Fourteen cases of BSCC involving the nasal cavity and paranasal sinuses were identified in the files of the Otolaryngic-Head and Neck Pathology Tumor Registry of the Armed Forces Institute of Pathology from 1975-1997. Clinical records and follow-up were available in all cases. Paraffin blocks were available for histochemical and immunohistochemical studies in all cases. RESULTS. There were 7 females and 7 males, ages 32-86 years (median, 66.5 years; mean, 62 years). The patients presented primarily with a mass lesion and unilateral nasal obstruction. In nine patients the tumor was confined to the nasal cavity. In three patients the tumor involved the sinuses alone and in two patients the tumor involved the nasal cavity and paranasal sinuses. Histologically, the tumors were widely invasive with a variety of growth patterns, including lobular, solid, trabecular, cribriform, and fascicular. The neoplastic infiltrate included predominantly pleomorphic, basaloid-appearing cells with hyperchromatic nuclei, inconspicuous to prominent nucleoli, and a variable amount of eosinophilic to clear-appearing cytoplasm. Mitotic figures, including atypical forms, were readily apparent as was necrosis (individual cell and comedo-type). Foci of squamous differentiation were limited in extent but were found in all cases and included squamous whorls, individual cell keratinization, and intercellular bridges. Intraepithelial dysplasia, carcinoma in situ, or invasive squamous carcinoma was present in all cases. Other histologic features included intercellular stromal hyalinization and peripheral nuclear palisading. In two cases, neural-type rosettes were found. Immunoreactivity for a variety of epithelial markers including cytokeratin (AE1/AE3/LP34), CAM 5.2, 34βE12, CK7, and epithelial membrane antigen was present in all cases. Variable reactivity was present with vimentin, actins (smooth muscle and muscle specific), neuron specific enolase, S-100 protein, glial fibrillary acidic protein, CK20, carcinoembryonic antigen, Leu7, and Ewing's marker. Chromogranin, synaptophysin, neurofibrillary protein, leukocyte common antigen, HMB-45, desmin, and Epstein-Barr virus latent membrane protein were absent. Surgical resection was the treatment of choice. Eight patients had recurrent or persistent tumor and metastatic disease occurred in five patients. At last follow-up, 7 patients (50%) had died of disease with a median survival of 12 months from the time of diagnosis and 3 patients were alive with disease over periods ranging from 8 months-5 years. Of the 4 remaining patients, 2 were alive without disease at 1 month and 5 years, respectively, 1 patient was lost to follow-up with no evidence of tumor at 3 years, and 1 patient had died of unrelated causes with no evidence of disease. CONCLUSIONS. Sinonasal BSCC is a histologically distinct variant of squamous cell carcinoma with pathologic features and aggressive biologic behavior similar to BSCC localized to more common mucosal sites of the upper aerodigestive tract.

有きょく細胞癌，基底細胞癌および日光角化症を併発した１例

A 80-year-old man occured with squamous cell carcinoma, basal cell carcinoma and solar keratosis is reported. He had a 16×14mm sized nodule on his left hand, two black papules, 6×7mm and 3×4mm, on his nose and hyperkeratotic pigmented macules on his scalp. Histpathologically, the tumor on the hand showed hyperkeratosis, papillomatosis and acanthosis with atypical squamoid cells. They contained many individual cell keratinization and mitotic figures. Both papules on the nose were composed with basaloid tumor cell nests. The peripheral cell layer of the nests showed palisade arrangement of the nuclei. The macule on the scalp showed hyperkeratosis, parakeratosis and cellular atypicality in the basal cell layer. The upper dermis showed inflammatory cell infiltration and solar degeneration. The occurrence of squamous cell carcinoma, basal cell carcinoma and solar keratosis in one person seems to be rare.