Serrano MF, El-Mofty SK, Gnepp DR, et al. Utility of high molecular weight cytokeratins, but not p63, in the differential diagnosis of neuroendocrine and basaloid carcinomas of the head and neck
High-grade neuroendocrine carcinomas of the head and neck overlap significantly in morphology with both basaloid squamous and solid-type adenoid cystic carcinomas. High-grade neuroendocrine carcinomas have sheets of small cells with scant cytoplasm, granular chromatin, and inconspicuous nucleoli. Basaloid squamous and adenoid cystic carcinomas are aggressive variants of their respective tumor types which both have nests of basaloid tumor cells with round nuclei, little cytoplasm, and inconspicuous nucleoli. As the management and prognosis of these tumors are very different, it is important to differentiate them. We performed high molecular weight cytokeratin (CK) and p63 immunohistochemistry on 19 neuroendocrine carcinomas, 18 basaloid squamous carcinomas, and 11 solid-type adenoid cystic carcinomas. All tumors were immunostained for p63, CK 34betaE12, CK 5/6, synaptophysin, chromogranin-A, S-100, and smooth muscle actin. All basaloid squamous and adenoid cystic carcinomas were positive for CK 5/6 and 34betaE12. Only 4 and 5 of the 19 neuroendocrine carcinomas, respectively, were positive for these markers. Staining was focal in the neuroendocrine cases when positive, whereas almost all basaloid squamous and adenoid cystic carcinomas showed strong staining. Almost all tumors of each type were positive for p63, including neuroendocrine carcinomas, but with different staining patterns. Basaloid squamous carcinomas were diffusely positive, neuroendocrine carcinomas were diffusely positive, but with weak staining, and adenoid cystic carcinomas showed a distinct pattern with staining at the periphery of the cell nests only. We conclude that high molecular weight cytokeratin immunostaining is helpful in distinguishing high-grade neuroendocrine carcinomas from similar tumor types.
[Show abstract] [Hide abstract] ABSTRACT: Although squamous cell carcinoma (SCC) variants account for less than 10% of all laryngeal SCCs, they have many unique biological, morphological, and clinical features. They are also easily confused with other tumor types. Recognition of them is critical for surgical pathologists as is the knowledge of what they mean for the patient. Three of the most common and important of these are basaloid, verrucous, and papillary SCC. These tumor types will be briefly reviewed with a focus on specific controversies, biological questions, and/or recent advancements in our understanding of them.0Comments 9Citations
- "However, one immunostain , in particular, that has been found useful to tell these tumors apart is p63, which will show patchy staining of adenoid cystic carcinoma with basal (myoepithelial) staining at the periphery of the solid nests. Basaloid SCC cells stain diffusely throughout . Non-keratinizing SCC of the oropharynx, as stated, arises in the oropharynx and not the larynx. "
[Show abstract] [Hide abstract] ABSTRACT: Basaloid squamous cell carcinoma (BSCC) is a distinctive variant of squamous cell carcinoma (SCC) with more aggressive behavior. It occurs preferentially in the upper aerodigestive tract. Sinonasal tract BSCC is uncommon, and only limited studies have been reported in literature. In these studies, most BSCCs arose from the nasal mucosa with or without extension to the paranasal sinuses. Rare reported cases of BSCC involved only the paranasal sinus. In this report, we present a case of a female patient with a sphenoid sinus mass. Clinically, the patient had progressively decreasing vision and headache. Magnetic resonance imaging (MRI) and computerized tomographic (CT) scan showed an infiltrating tumor mass involving the sphenoid sinus and the sella with compression of the optic nerve. Pathologic examination revealed an invasive basaloid epithelial neoplasm that was arranged in lobules, nests and cords. The tumor also showed palisading of peripheral cells, focal abrupt squamous differentiation and in situ carcinoma in the surface mucosa. In the immunohistochemical studies, this tumor revealed a strongly positive nuclear staining for p63. The morphologic and ancillary studies indicated a BSCC. To the best of our knowledge, this is the first report of sinonasal tract BSCC that mainly involved the sphenoid bone and sella. In this region, BSCC should be distinguished from benign and malignant neoplasms that more often affect sella and base of skull, such as pituitary adenoma with extensive necrosis, small cell neuroendocrine carcinoma (SCNC), olfactory neuroblastoma, malignant germ cell tumor, paranasal adenoid cystic carcinoma (ACC), and a variety of metastatic malignancies.0Comments 5Citations
- "Other tumors that may involve the sella, such as primary germ cell tumor and metastatic malignancies also need to be considered in the differential diagnosis. Application of immunohistochemical studies may be necessary to differentiate BSCC from other neoplasms, particularly when transsphenoidal biopsy specimens are small or biopsy artifacts are present [13, 14]. BSCC are usually negative for neuroendocrine markers such as CD56, synaptophysin and chromogranin although S-100 protein may be weakly positive in some case. "
- [Show abstract] [Hide abstract] ABSTRACT: The application of immunohistochemistry in the diagnostic gastrointestinal pathology is similar to many other organ systems. The most commonly used markers are epithelial cell markers such as cytokeratin AE1/3, cytokeratin 7 and cytokeratin 20, and markers for common mesenchymal tumors such as CD117, CD34, S100, desmin, etc. Tumors of neuroendocrine origin are probably more commonly seen in the digestive and pulmonary systems. A synaptophysin and chromogranin immunostain generally can confirm their neuroendocrine nature. Use of immunohistochemical studies to evaluate dysplasia in Barrett’s esophagus is still investigational, although many have found p53 overexpression helpful in confirming dysplasia, particularly in high-grade dysplasia. The use of immunohistochemical studies in nonneoplastic diseases of the gastrointestinal tract is limited. Finally, immunohistochemistry, like GCDFP-15 immunostain, may play a critical role in differentiating certain metastases, such as lobular carcinoma of the breast, from primary tumors, including gastric signet ring cell carcinoma. KeywordsDysplasia-Carcinoma-GIST-Neuroendocrine-Metastasis-Keratin-CD117-Synaptophysin0Comments 7Citations