Neuroendocrine carcinoma

Sometimes the distribution of keratin staining in a particular cell may aid in determining its origin. As mentioned before, Merkel cell and other neuroendocrine carcinomas characteristically have a perinuclear ball-like reactivity. 

Abnormal tissues The antibody labeled 17/20 sarcomas, 16/18 melanomas, 4/4 meningeomas, and 3/3 schwannomas, and was the sole intermediate filament present in these tumours. In addition, variable percentages (10 to 57 percent) of carcinomas, neuroendocrine carcinomas, neuroblastomas, thymomas and mesotheliomas were positive with the antibody. With the exception of the neuroblastomas, cytokeratin was coexpressed with vimentin in these tumours. Among adenocarcinomas, more than 50 percent of papillary carcinomas of the thyroid as well as renal, endometrial, ovarian and lung carcinomas were labeled by the antibody and coexpressed keratins and vimentin. 

Initial clinical trials were executed using the labelling methods described above the results are shown in Figs 13.13-13.15. The investigations confirmed that bremsstrahlung scintigraphy can be used to estimate the effectiveness of therapy. A decrease in the uptake of °Y-DOTATATE in neuroendocrine carcinoma metastases was observed during the course of the treatment. This... 

FIG. 13.13. Results of the first clinical trials with OTATATE diagnostic images of a 36 year old patient (patient No. 1) with a low grade neuroendocrine carcinoma (a) fin-octreotide scan (b) " Tc-HYNIC-TATE scan. 

N. Masumori, T.Z. Thomas, P. Chaurand, T. Case, M. Paul, S. Kasper, R.M. Caprioli, T. Tsukamoto, S.B. Shappell and R.J. Matusik, A probasin-large T antigen transgenic mouse line develops prostate adenocarcinoma and neuroendocrine carcinoma with metastatic potential. Cancer Research, 61, 2239-2249 (2001). 

Weitman et al. showed by Northern blot analysis and immunoassays that the folate receptor (type-a) has a very restricted normal tissue distribution (4). Highly elevated receptor expression was only found in the choroid plexus and malignant tissues (4). Garin-Chesa et al. showed by immunohistochemi-cal staining that 52 of 56 ovarian tumor samples displayed highly elevated folate receptor (type-a) expression (5). Receptor overexpression was also found in 10 of 11 endometrial, 6 of 27 colorectal, 11 of 53 breast, 6 of 18 lung, 9 of 18 renal cell, 4 of 5 brain metastases, and 3 of 21 neuroendocrine carcinomas (5). 

Soslow RA, Wallace M, Goris J, et al. MIC2 gene expression in cutaneous neuroendocrine carcinoma (Merkel cell carcinoma). Appl Immunohistochem. 1996 4 235-240. 

FIGURE 7.2 Small cell amelanotic melanoma, resembling neuroendocrine carcinoma. 

Neuroendocrine carcinomas may be separated from MM by attention to keratin reactivity patterns and positivity for chromogranins and synaptophysin. " As stated earlier, melanocytic lesions lack the latter two markers consistently, whereas at least 50% of... 

It is well known that a few neuroendocrine cells can be seen with IHC in a wide variety of carcinomas. This is not to be equated with a diagnosis of neuroendocrine carcinoma. Only after a complete account of the clinical findings, imaging studies, histologic studies, and immunohistochemical findings should a diagnosis be rendered. 

Large cell undifferentiated neuroendocrine carcinoma (LCNEC) can present as CUPS, and it is easy to miss the diagnosis without applying the appropriate neuroendocrine markers. The correct diagnosis of LCNEC is an important distinction because it carries the same dismal prognosis as does small cell carcinoma, whether in the lung or gastrointestinal tract. 776 Synaptophysin may be the most frequent positive marker in LCNEC. ... 

Subsets of neuroendocrine carcinomas of gastrointestinal tract may be CDX-2+ (see text). 

Chan JK, Suster S, Wenig BM, et al. Cytokeratin 20 immuno-reactivity distinguishes Merkel cell (primary cutaneous neuroendocrine) carcinomas and salivary gland small cell carcinomas from small cell carcinomas of various sites. Am J Surg Pathol. 1997 21 226-234. 

Nandedkar MA, Palazzo J, Abbondanzo SL, et al. CD45 (leukocyte common antigen) immunoreactivity in metastatic undifferentiated and neuroendocrine carcinoma a potential diagnostic pitfall. Mod Pathol. 1998 11 1204-1210. 

Staten ED, Gould VE, Warren WH, et al. Neuroendocrine carcinomas of the colon and rectum a clinicopathologic evaluation. Surgery. 1988 104 1080-1089. 

Kaufmann O, Dietel M. Expression of thyroid transcription factor-1 in pulmonary and extrapulmonary small cell carcinomas and other neuroendocrine carcinomas of various primary sites. Histopathology. 2000 36 415-420. 

TABLE 9.2 Differentiating Basaloid Squamous Cell Carcinoma from Adenoid Cystic and Small Cell Neuroendocrine Carcinoma ... 

The differential diagnosis for BSCC can be broad, especially in small biopsies where it can be difficult to appreciate all of the histologic features. Included in the differential diagnosis are the two most important mim-ickers adenoid cystic carcinoma and small cell neuroendocrine carcinoma.Immunohistochemical stains are particularly useful in resolving this differential diagnosis (Table 9.2). 

The differential diagnosis for basaloid squamous cell carcinoma (BSCC) includes adenoid cystic carcinoma and small cell neuroendocrine carcinoma. 

Many of the tumors of the nasal cavity and paranasal sinuses fall under the category of round cell neoplasms. Among these are olfactory neuroblastoma, sinonasal undifferentiated carcinoma, malignant melanoma, neuroendocrine carcinoma-small cell neuroendocrine carcinoma, malignant lymphoma, extramedullary plasmacytoma, invasive-ectopic pituitary adenoma, rhabdomyosarcoma, and Ewing s sarcoma (ES)-peripheral neuroectodermal tumor (ES/ PNET). But there is also a host of other epithelial lesions that are unique to the sinonasal tract. 

TABLE 9.6 Sinonasal Undifferentiated Carcinoma (SNUC) versus Small Cell Neuroendocrine Carcinoma (SCNEC) ... 

Small Cell Neuroendocrine Carcinoma and Neuroendocrine Carcinoma... 

The differential diagnosis for neuroendocrine tumors in the sinonasal tract will include olfactory neuroblastoma, small cell neuroendocrine carcinoma, carcinoid, atypical carcinoid, paraganglioma, and possibly even sinonasal undifferentiated carcinoma. Once these more specific neuroendocrine entities have been excluded, there remains a small group of tumors that cannot be further classified. These should be referred to as neuroendocrine carcinoma, not otherwise specified. These tumors can be graded using standard morphologic features. 

Small cell neuroendocrine carcinomas similar to those seen in the lung are exceptionally rare in the nasal cavity and paranasal sinuses. They affect both sexes equally and occur over a broad age range (38 to 68 years in one studyThey may arise either in the nasal cavity or in the paranasal sinuses, especially the ethmoid and maxilla. Though some tumors will remain localized to the site of origin, higher grade tumors are likely to invade into adjacent structures such as the orbit, cribriform plate, or cranial cavity. 

Microscopically, small cell neuroendocrine carcinomas are identical to their pulmonary counterparts and, as such, are composed primarily of round to short spindle cells with sparse, poorly defined cytoplasm and hyperchromatic nuclei without nucleoli. Nuclear molding, frequent mitoses, necrosis, and single-cell apoptosis are common. 

Neuroendocrine carcinomas and small cell neuroendocrine carcinomas are almost invariably positive for cytokeratins (such as CAM 5.2 and AE 1/3), synaptophysin, chromogranin, and neuron-specific enolase. A dotlike pattern of positivity may be seen in cytokeratin stains. They are negative for cytokera-tin 20, S-100, and neurofilament.About half of small cell neuroendocrine carcinomas are positive for thyroid transcription factor (TTF-1) and at least one... 

Neuroendocrine carcinomas are positive for cytokeratins and for typical neuroendocrine markers, such as chromogranin and synaptophysin. 

The classification of neuroendocrine tumors of the head and neck has been controversial.The WHO classification has divided the tumors into four categories typical carcinoid, atypical carcinoid, small cell neuroendocrine carcinoma, and paraganglioma. Each of these tumor types is discussed separately. Immunohisto-chemical stains will not easily separate the four types of... 

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