Molecular pathology and potential therapeutic targets in esophageal basaloid squamous cell carcinoma

Basaloid squamous cell carcinoma (BSCC) is a rare and poorly differentiated variant of typical squamous cell carcinoma. Emerging studies show that genetic alterations are more frequent in BSCC than in conventional SCC, and some of which led to the identification of potential therapeutic targets in esophageal BSCC. Approximately half of the esophageal BSCC cases harbor either an EGFR mutation or amplification, and these occur in a mutually exclusive fashion. Therefore, the application of tyrosine kinase inhibitors may be beneficial to esophageal BSCC patients. This tumor is partly characterized by the activation of the Wnt and Hedgehog (HH) signaling pathways. Wnt signaling is activated by SFRP2 promoter hypermethylation and HH signaling is activated by the frequent mutations in PTCH1. Increasing evidence shows that the Wnt signaling pathway is involved in cross-talk with other developmental pathways, including the HH pathway. Therefore, pharmaceutical therapy targeting both the HH and Wnt pathways would be quite effective in patients with esophageal BSCC with highly malignant potential. In this review, we discuss the pathology, prognostic factors, genetic alterations and potential therapeutic targets in BSCC of esophagus.     

Expression of Bcl-2 and Amplification of c-myc Are Frequent in Basaloid Squamous Cell Carcinomas of the Esophagus

Basaloid squamous cell carcinoma (BSCC) of the esophagus is a rare, poorly differentiated variant of typical esophageal squamous cell carcinoma (SCC) characterized by high proliferative activity and frequent spontaneous apoptoses. In the present study, we investigated the expression of the apoptosis-suppressing protein Bcl-2 in 23 BSCC of the esophagus and 23 stage-matched typical esophageal SCC by means of immunohistochemistry. In addition, amplification of the apoptosis- and proliferation-inducing gene c-myc was determined by means of differential polymerase chain reaction. Bcl-2 expression was found significantly more often in BSCC than in SCC (86.9% vs. 17.4%, P < 0.0001). Amplification of c-myc was nearly twice as common in BSCC as in SCC (47.8% vs. 26.1%, not significant). Bcl-2 protein expression together with c-myc amplification was detected in 43.5% of the BSCC but in none of the typical SCC (P < 0.0001). Taken together, our findings indicate that the molecular pathogenesis of esophageal BSCC differs from that of typical SCC and frequently involves coactivation of c-myc and Bcl-2.     

43例食管基底样鳞状细胞癌临床病理分析

目的探讨食管基底样鳞状细胞癌（basaloid squamous cell carcinoma,BSCC）临床病理特点。方法对43例食管BSCC进行组织形态学及免疫组化观察,并对其临床病理特点及随访资料进行分析。结果BSCC由类似于鳞状上皮基底细胞样的细胞组成,细胞排列呈实性巢状、小梁状、假腺样或筛状结构,巢周边瘤细胞常呈栅栏状排列,巢中央可见粉刺样坏死。24例（55.8％）与普通鳞癌或腺鳞癌并存,11例（25.6％）出现局灶鳞化,28例（65．1％）见到脉管内癌栓。免疫组化染色CKpan、AE1、AE3均呈不同程度的阳性表达,p53、Ki-67、PCNA呈中至强阳性表达,Syn、CgA分别有1例呈弱阳性,S-100蛋白、SMA、CEA均为阴性。结论BSCC是食管一种少见的鳞状细胞癌变异型,具有独特的形态特点和明显的侵袭性行为,预后较差。免疫组化无特异性,诊断主要依靠形态学特点。     

Skin Metastasis of Hypopharyngeal Carcinoma to the Nasal Tip

Head and neck squamous cell carcinoma (SCC) rarely metastasizes to the skin. Metastases to the nasal tip from hypopharyngeal malignancies are extremely rare. We present a patient with nasal tip metastasis from hypopharyngeal SCC. A 74-year-old man with hypopharyngeal and esophageal carcinomas had a red nodule on his nasal tip (so-called “clown nose”). Histopathologically, atypical squamoid cell nests had proliferated in a lobular fashion from the dermis to subcutaneous tissue. Those atypical cells were identical to primary tumor cells in the hypopharynx. Based on these findings, a diagnosis of skin metastasis from hypopharyngeal SCC was made. In patients with malignant disease, biopsy should be performed for any suspicious skin lesion. In a patient like ours, “clown nose” might be a symptom of cutaneous metastasis. When clinicians note a “clown nose”, they should consider malignancies in the neck and chest areas.     

Comparative analysis of basaloid and typical squamous cell carcinoma of the oesophagus: a molecular biological and immunohistochemical study

Twenty-three cases of basaloid squamous cell carcinoma (BSCC) and 23 stage-matched pairs of typical squamous cell carcinoma (SCC) of the oesophagus were investigated for molecular aberrations. Polymerase chain reaction (PCR) was used to detect loss of heterozygosity at the APC, RB, and MCC gene loci, while differential PCR was carried out to detect amplification of the CDK4 gene. In addition, the level of expression of the p53 and RB proteins in the tumour tissue was assessed by immunohistochemistry. Loss of heterozygosity (LOH) at the APC and MCC loci was about twice as common in BSCC as in SCC (40% vs. 21% and 33% vs. 12%, respectively), with co-existence of LOH at both loci occurring only in BSCC. LOH frequency at the RB gene locus was not remarkably different in either BSCC or SCC (20% vs. 24%, respectively). On immunohistochemistry, accumulation of p53 protein was slightly more frequent in BSCC than in SCC (61% vs. 52%), whereas the rate of loss of RB protein expression was about equal in both types of carcinoma (9% vs. 13% BSCC and SCC, respectively). There was no detectable amplification of the CDK4 gene in either type of tumour. Although the observed differences did not achieve statistical significance, this work has further highlighted possible differences between the molecular pathogenesis of BSCC and SCC.     

Common genomic aberrations in basaloid squamous cell carcinoma and carcinosarcoma of the esophagus detected by CGH and array CGH

Basaloid squamous cell carcinoma (BSCC) and carcinosarcoma of the esophagus are rare entities, making up fewer than 2% of esophageal malignancies. Comparative genomic hybridization (CGH) in 1 case of BSCC and 2 cases of carcinosarcoma and subsequent array CGH in 1 case each of BSCC and carcinosarcoma revealed common chromosomal gains at 2p25.3-2p12, 7q21.3-7q22.3, and 11q13.2-11q13.4. Chromosomal losses at 13q31qter were observed in both carcinosarcomas. In addition, progression of genomic instability from in situ to invasive carcinosarcoma could be demonstrated by using array CGH. Our observations suggest a common genetic origin of BSCC and carcinosarcoma.     

Oesophageal basaloid squamous cell carcinoma: a unique clinicopathological entity with telomerase activity as a prognostic indicator.

Oesophageal basaloid squamous cell carcinoma (BSCC) is uncommon and has been reported to have a worse prognosis than squamous cell carcinomas (SCCs), but this tumour has not been fully characterized. The aim of the present study was to analyse the clinicopathological features of a large cohort of patients with oesophageal BSCC treated at a single institution. The pathology of 756 primary oesophageal cancers treated between January 1989 and December 1998 was reviewed. Tumours that fulfilled the diagnostic criteria of BSCC were identified and were compared with SCC. Their expression of MIB-1, DNA ploidy, and telomerase activity were also studied. Thirty Chinese patients (25 men and five women) with BSCC were found, comprising 4% of patients with oesophageal cancer treated by surgical resection in the study period. Their median age was 67 years (range 40-78 years). Dysphagia was usually the main presenting symptom. Other concomitant malignant tumours were seen in three patients and paraneoplastic glomerulopathy in one. Five tumours were located in the upper third, 19 in the middle third, and six in the lower third. The median length was 5.8 cm (range 2-12 cm). The median MIB-1 score of BSCC was 750 (range 400-858) and was higher than that of SCC (p=0.003). The primary tumour and metastatic BSCC were aneuploid, as detected by flow cytometric analysis in nine patients. Telomerase activity was positive in 95% (19 out of 20) of the cases analysed. The 5-year survival of patients with BSCC was 12%. Distant metastases were seen in 53% (n=16); lung and liver were the most common sites. The median survival of patients with tumours which had a high level of telomerase activity was significantly shorter than those with low levels of telomerase activity (1 vs. 27 months) (p=0.001). The median survival of patients with BSCC and SCC was 26 and 16 months, respectively (p=0.3). In conclusion, BSCC has distinctive clinicopathological features and its long-term prognosis is no worse than SCC. The level of telomerase activity may have a prognostic role.     

Squamous cell carcinoma variants of the head and neck

Variants of squamous cell carcinoma (SCC) frequently arise within the mucosa of the upper aerodigestive tract, accounting for up to 15% of SCCs in these areas. The most common variants include verrucous, exophytic or papillary, spindle-cell (sarcomatoid), basaloid and adenosquamous carcinoma. Each of these variants has a unique histomorphologic appearance, which raises a number of different differential diagnostic considerations, with the attendant clinically relevant management decision.Verrucous squamous cell carcinoma has a broad border of pushing infiltration of a non-dysplastic squamous epithelium, essentially devoid of mitotic figures, displaying hyperkeratosis on elongated rete pegs. Papillary and exophytic SCC have a papillary or exophytic architecture, but have malignant cytologic features within the epithelium. Spindle-cell (sarcomatoid) carcinoma is an SCC blended with a spindle-cell morphology, frequently mimicking other mesenchymal tumours. Epithelial markers are often negative. Basaloid SCC is a high-grade SCC variant with small cells arranged in a palisaded architecture, with hyperchromatic nuclei and only focal areas of squamous differentiation. Adenosquamous carcinoma is a rare variant, which is a composite of adenocarcinoma and squamous cell carcinoma, often with areas of transition. The cytomorphologic features are described in detail in an attempt to allow the general surgical pathologist to separate these variants of SCC in order to achieve appropriate clinical management.     

Necrotizing sialometaplasia-like change of the esophageal submucosal glands is associated with Barrett’s esophagus

Basaloid squamous cell carcinoma (BSCC) of the esophagus is a rare variant of typical squamous cell carcinoma (SCC) associated with poor survival. A characteristic feature is nuclear accumulation of β-catenin, without a mutation of the gene. We studied the methylation status of Wnt antagonist genes, such as secreted frizzled-related protein (sFRP) gene family members, Wnt inhibitory factor-1 (WIF-1), Dickkopf-1 (Dkk-1), and human Dapper protein-1 (HDPR-1), and alterations of the APC, Axin1, and Axin2 genes in 30 cases of esophageal BSCC. β-catenin and sFRP (sFRP-1, sFRP-2, sFRP-4, sFRP-5) protein expression was examined by immunohistochemistry. APC, Axin1, and Axin2 gene mutations were detected in 3, 2, and 2 cases, respectively, and 6 cases (20 %) harbored at least 1 alteration in these genes. Methylation of the sFRP-2 promoter region was observed in all cases, and methylation was frequent in sFRP-1 and sFRP-5, but infrequent in Dkk-1, WIF-1, sFRP-4, and HDPR-1. sFRP-2 expression was almost completely absent in 25 cases (83 %), consistent with the methylation status. Nuclear accumulation of β-catenin was observed in all cases. sFRP-5 expression was associated with a low nuclear β-catenin labeling index. These results show that sFRP-2 is a target gene of hypermethylation in esophageal BSCC and suggest that sFRP-2 might contribute to BSCC tumorigenesis through the Wnt/β-catenin signaling pathway.     

Hybrid verrucous squamous cell carcinoma of sinonasal tract: a case report.

Verrucous carcinoma is a variant of squamous cell carcinoma and should be distinguished from benign papilloma and well-differentiated nonverrucous squamous cell carcinoma. It is rare tumor of the sinonasal tract. Occasionally, conventional squamous cell carcinomatous components may be seen in verrucous carcinoma. This entity is called a hybrid verrucous squamous cell carcinoma. We report a case of hybrid verrucous squamous cell carcinoma occurring in the nasal cavity and paranasal sinus of a 67-year-old male. The removed mass shows the typical feature of verrucous carcinoma, but focally conventional squamous cell carcinomatous area is also noted. The treatment of this case follows verrucous carcinoma, but close follow up is mandatory because it may potentially spread to regional lymph nodes in contrast to pure form of verrucous carcinoma.     

Superficial esophageal carcinoma. With special reference to basaloid features

A total of 200 surgically resected esophageal carcinomas were reviewed and 50 cases (25.0%) were identified as "superficial esophageal carcinoma" (depth of invasion limited to mucosa or submucosa). The age, sex, location, tumor size, histological features, and prognosis were studied in 49 of these cases. The carcinomas were classified into four histological groups: 1) squamous cell carcinoma (SCC), 2) squamous cell carcinoma with basaloid features and expansive growth (BE), 3) squamous cell carcinoma partially mixed with the basaloid type (mixed), and 4) other types of tumors. There were 25 cases (51.0%) of SCC, 14 BE cases (28.6%), 8 mixed cases (16.3%), and 2 (4.1%) other tumors (malignant melanoma, adenoacanthoma). Among 133 advanced cancers (invasion into and beyond the muscularis propria), there were 123 cases (92.4%) of SCC, 9 (6.8%) mixed cases, and one (0.8%) adenoacanthoma. No BE lesions were identified. In superficial carcinoma there was a statistically significant difference between BE and mixed carcinoma by the chi-square test (p less than 0.05) with regard to the maximum longitudinal diameter. None of the BE carcinoma showed nodal metastasis, while 3 (12.0%) of SCC and 5 (62.5%) of mixed lesions had nodal metastases. The difference in cumulative survival rate between BE and mixed carcinoma was statistically significant by the Z and Wilcoxon tests (p less than 0.05). We conclude that the BE type of superficial esophageal carcinoma had a better prognosis, and should be separated from the ordinary SCC with infiltrative growth from a clinicopathological view point.     

Combined hepatocellular and cholangiocarcinoma with marked squamous cell carcinoma components arising in non-cirrhotic liver

We report a surgical case of liver tumor, 40 x 35 mm in size, with squamous cell carcinoma (SCC) and hepatocellular carcinoma (HCC) components in a 60-year-old Japanese man with steatohepatitis. Most of the SCC component showed typical intercellular bridge and keratinization, while most of the HCC components showed a thick trabecular pattern with mild to moderate nuclear atypia. Both components transit each other without undifferentiated foci; however, a small foci showing glandular structure was intermediated. No cyst formation was found in the liver. The primary site of the squamous cell carcinoma was not detected in general clinical and radiological examination. Immunohistochemical analysis revealed that part of the HCC components neighboring the SCC showed patchy and weak expression of cytokeratin 7. There are several possibilities for the origin of squamous cell carcinoma in this case: marked squamous metaplastic change of cholangiocarcinoma and/or HCC, and carcinoma originating from pleuripotential stem cells. Irregular fatty changes, scattered giant mitochondria and acellular fibrosis with bridging were seen in the liver; however, this patient had no episode of hepatitis-associated viral infection. This is an interesting case of combined hepatocellular and cholangiocarcinoma with marked SCC components arising in a non-cirrhotic fibrotic liver.     

Basaloid squamous carcinoma of the larynx. A potential diagnostic pitfall

Basaloid squamous carcinoma is a rare variant of squamous cell carcinoma. It is frequently diagnosed at an advanced stage with metastases. Histologically, it is identical to basaloid carcinoma at other anatomical sites. Some authors suggest that it may be associated with second primary tumors. Others implicate the Epstein-Barr and human papilloma viruses. All reports but one warn of its aggressive biological behavior. Our case concerns a 52-year-old man who had a small lesion in his right cord. Biopsy of the lesion was performed twice, and conventional squamous cell carcinoma was diagnosed; the patient returned 2 months later with progressed metastatic disease. The patient underwent a laryngectomy and a complete clinical and immunohistochemical investigation. Basaloid squamous carcinoma is a totipotential neoplasm with a grave prognosis. It can be misdiagnosed; therefore, the authors would like to emphasize the significance of this condition in comparison to conventional squamous cell carcinoma, and we provide a review of the relevant recent literature.     

p53 Overexpression in laryngeal squamous cell carcinoma and dysplasia

Aim—To investigate the expression of p53 protein in invasive squamous cell carcinoma (SCC) of the larynx and dysplasia in relation to histological grade and tobacco smoking.     

Eosinophil-rich squamous carcinoma of the oral cavity: a study of 13 cases and delineation of a possible new microscopic entity

We report 13 cases of squamous cell carcinoma (SCC) of the oral cavity characterized by a prominent eosinophilic infiltration of the stroma. All patients were adults, 10 men and 3 women (aged 54 to 92 years; median, 71 years). They presented with tumors of the gingiva (5 cases), tongue (3 cases), palatine tonsil (2 cases), palate (2 cases), and mucosal aspect of lip (1 case). Metastatic involvement of regional lymph nodes was seen in 5 cases. The metastatic foci were associated with heavy eosinophilia as well. No patient had an abnormal eosinophil count in blood. Microscopically, the clusters of eosinophils were characteristically noticed in intimate admixture with the advancing edge of squamous carcinoma, either as nests or small tumor cords. The pattern of eosinophilic infiltration was comparable, regardless of tumor site or grade. Data from our series indicate that SCC with a reactive inflammatory infiltrate rich in eosinophils is consistently associated with stromal invasion. This observation may be useful in dealing with small tissue fragments where subepithelial stromal invasion cannot be easily assessed by conventional criteria. In addition, our data seem to confirm that eosinophil-rich SCC, although associated with metastatic involvement of cervical lymph node, seems to pursue a less aggressive course if compared with ordinary SCC.     

Prevalence of high-risk human papillomavirus in primary squamous cell carcinoma of urinary bladder

Studies have demonstrated an etiologic role of high-risk human papillomavirus (HR-HPV) infection for epithelial malignancies, including most cervical carcinomas, anogenital cancers, and carcinomas of the head and neck; however, a causative role of HPV infection for bladder cancer is controversial. The purpose of this study was to investigate the prevalence of HR-HPV in primary bladder carcinoma to determine the association between HPV infection and the squamous cell component of urothelial carcinoma of the bladder. Furthermore, we evaluated the utility of p16 overexpression as a surrogate marker for HPV infection in these cancers and the correlation of this with tumor stage. Our study included 33 cases of squamous cell carcinoma (SCC) of the urinary bladder. Tumors deemed primary from the bladder were selected and either showed predominant (>50 %) or pure squamous differentiation. Immunohistochemical study for p16 and HR-HPV by RNA in situ hybridization (ISH) was performed in all cases. p16 expression was detected in 7 cases (28 %, 7/25) of urothelial carcinoma with squamous differentiation and not detected in any of the 8 cases (0%, 0/8) of pure SCC. Detection of HR-HPV by ISH was negative in all 33 cases (0%, 0/33). There was no association between p16 overexpression and the presence of HPV infection in squamous cell carcinomas of the bladder. p16 should not be used as a surrogate marker for evidence of HPV infection. Our study suggests that HPV infection does not play an etiologic role in the development of bladder cancer and should not be used as a diagnostic adjunct for these cases.     

Clear cell variant of squamous cell carcinoma originating in the esophagus: report of a case with immunohistochemical and oncogenetic analyses

The cutaneous clear cell squamous cell carcinoma (SCC) is a rare tumor thought to be associated with hair follicle or skin appendage differentiation. We report herein a rare variant case of a clear cell SCC originating in the esophagus. A 70-year-old Japanese man was found to have a tumor in the esophagus. The excised neoplasm showed dominance of clear cell over conventional SCC components; the two components in an apparent continuum. The clear cells, regular in size with a moderate nuclear/cytoplasmic ratio and relatively hyperchromatic and centrally located nuclei, were compactly arranged in sheets. Glycogen deposition was apparent on PAS staining with or without diastase digestion and under the electron microscope. The clear cell SCC components were positive for cytokeratin (CK)7, CK8, CK18 and CK19, but were negative for CK5/6 or CK14. Reciprocal staining patterns of CKs were apparent in conventional SCC components. The present case and cutaneous clear cell SCC counterparts share some histopathologic characteristics whereas CKs expression differs between the two. Overexpression of p53 protein, without evidence of any mutation, and reduced p16(INK4a) were noted in both clear cell and conventional SCC components. No mutations of Kras, BRAF or β-catenin genes were found in both tumor components.     

First reported case of a squamous cell carcinoma arising in the duodenum in a patient with Lynch syndrome

A 58 y/o male with Lynch syndrome, who was diagnosed with a squamous cell carcinoma (SCC) arising in the duodenum, is described. Previous malignancies included two metachronous colorectal adenocarcinomas, and a known family history of Lynch syndrome associated with deletion of exons 8-15 of the MSH2 gene. Analysis of his small bowel SCC revealed loss of MSH2 and MSH6 protein expression, suggesting a pathogenic role of the germ-line deletion. While small bowel adenocarcinomas have previously been reported in Lynch syndrome, to our knowledge this is the first report of Lynch syndrome-associated squamous histology. As patients with Lynch syndrome live longer with early detection and treatment of their cancers, unusual sites and histology of previously unreported cancers may emerge. It is also important to recognize variant histologies that otherwise might not prompt pursuing a diagnosis of Lynch syndrome in the appropriate clinical setting.     

Squamous cell carcinoma of breast--report of two case

Squamous cell carcinoma is an extremely rare variant of breast cancer. Presence of unequivocal squamous differentiation should be observed to diagnose a case as squamous cell carcinoma of breast since focal squamous metaplasia is frequently seen in common variants of breast carcinoma. We report here two cases of squamous cell carcinoma of breast, one a primary metaplastic type and the other one metastatic from a carcinoma of the cervix.     

Hematologic malignancies of the female genital tract diagnosed on liquid-based Pap test: Cytomorphologic features and review of differential diagnoses

The female genital tract is rarely the primary site for hematologic malignancies; however, secondary involvement of this anatomic site is common. Primary lymphomas of the gynecologic tract are reported to represent less than 1% of extranodal non-Hodgkin lymphomas (NHL), and the majority of them being B-cell in origin. Diffuse large B-cell lymphoma is the most common subtype, whereas primary extraosseus plasmacytoma of the genital tract is rare.If clinically not suspected, these rare tumors pose a diagnostic challenge both for clinicians and pathologists. Clinical symptoms are often nonspecific and mimic other more common gynecologic malignancies such as squamous cell carcinoma of the cervix or endometrial adenocarcinoma. Although cervico-vaginal (Pap) smear is the primary screening method for cervical squamous cell carcinoma and its precursors, it is far less sensitive for detection of other primary or metastatic malignancies. In this review, we present three cases of hematologic gynecologic malignancies, two cases of primary NHL, and a case of acute myeloid leukemia with relapse as a pelvic mass, all of which were diagnosed on a liquid-based Pap test. In addition, we discuss the morphologic features of differential diagnostic entities of these rare tumors on conventional and liquid-based preparations.