Polypoid squamous carcinoma of the esophagus. A case report with immunostaining for keratin

Sarcomatoid Carcinoma of the Transverse Colon With Extremely Aggressive Brain Metastases

Introduction

Sarcomatoid carcinoma (SC) is a rare subtype of malignant neoplasm with a poor prognosis that involves both carcinomatous and sarcomatous components. Although it may develop in various organs, SC in the large intestine has rarely been reported. It is not rare for patients with SC to have distant metastasis, reflecting its highly aggressive oncologic features, but cases with brain metastasis on initial visit are rare. In this report, we described a case of SC in the transverse colon with brain metastases whose initial symptom was neurological disorder, and reviewed 31 reported cases of SC.

Case presentation

A 70-year-old man was admitted to our hospital with the chief complaints of gait disorder and severe dizziness. Head magnetic resonance imaging revealed tumor masses in the anterior lobe and cerebellum. A large tumor in the transverse colon was detected by colonoscopy and abdominal enhanced computed tomography (CT), and was diagnosed as undifferentiated adenocarcinoma by histology. Laparoscopic extended right hemicolectomy was performed to remove the obstruction, and the resected specimens revealed an invasive tumor consisting of a mixture of carcinomatous and sarcomatous components. According to the immunopathological study, the patient was diagnosed with SC. The clinical course was extremely aggressive, and the patient died on the 28th postoperative day because of disease progression.

Conclusion

To the best of our knowledge, this is the first case of SC in the transverse colon with a neurological disorder derived from brain metastases. This experience may contribute to the guidance regarding proper therapeutic options for SC.

Sarcomatoid Carcinoma of the Colon: A Case Report with Literature Review

Sarcomatoid carcinoma (SC) is a well defined tumor type that may occur in all organs and anatomic sites but most commonly in the head1, neck1, respiratory tract2-4, breast5, and genitourinary tract6-11. It is a biphasic tumor showing both epithelial- and mesenchymal-like differentiation; however, its carcinomatous nature is widely recognized12. SC is rare in the gastrointestinal tract. In the esophagus it accounts for less than 5% of all malignancies12-16 and approximately only 35 cases have been described in the stomach12,17-18. Very few cases have been observed in the small intestine19-20, anorectal junction21, liver22, and pancreas23-24. To our knowledge only eight cases of SC have been reported in the colon25-32. We report a case of primary colonic SC. Both morphological and immunohistochemical analyses are provided along with an evaluation of the unusual clinical history, therapeutic implications, and controversial differential diagnosis.

Polypoid Carcinoma of the Oropharynx with Stromal Ossifying Myofibroblastic Proliferation: A Case Report and Literature Review

A 76-year-old man reported a worsening difficulty in swallowing, leading to the inability to eat. Physical examination and CT scan revealed a polypoid mass on the posterior oropharynx and obstructing the oropharyngeal space. Histologically, the surface was ulcerated. In the underlying necrotic rim, there was active granulation tissue, and a proliferation of voluminous, globoid elements with hyperchromatic and irregular nucleus, sometimes arranged in a alveolar aggregate. The core of the lesion contained spindle-like myoid elements in interwoven bundles, with trabeculae of osteoid matrix maturing into calcified bone. Immunohistochemistry documented positivity for cytokeratins, epithelial membrane antigen, and P63 in the globoid elements beneath the necrotic rim; strong and diffuse expression of vimentin, smooth muscle actin, and CD99 and BCL2 in the spindle elements; and complete negativity for cytokeratin 5/6, high molecular weight cytokeratin (clone 34βE12), S100, muscle-specific actin, desmin, CD117, and anaplastic lymphoma kinase. The lesion was morphologically and immunophenotypically classified as a polypoid oropharyngeal carcinoma with ossifying myofibroblastic stromal proliferation.

Adenocarcinosarcoma in Barrett's Esophagus

Carcinosarcoma of the esophagus is a rare tumor with both carcinomatous and sarcomatous components. Usually the mesenchymatous component is predominant, and the carcinomatous part is a squamous cell carcinoma. We report the case of an old man having a large polypoid mass in the distal third of the esophagus, arising in Barrett's esophagus. The tumor consisted of a mixture of vimentin-positive sarcoma and keratin-positive adenocarcinoma. The adenocarcinomatous cells also expressed the epithelial membrane antigen and did not express vimentin. To the best of our knowledge, it is the second case of adenocarcinosarcoma in Barrett's esophagus published in the English literature. The prognosis of this peculiar tumor is uncertain.

Expression of receptor tyrosine kinases in esophageal carcinosarcoma

Esophageal carcinosarcoma (ECS) is a rare malignant neoplasm associated with a poor patient prognosis. It is characterized by the presence of both malignant epithelial and mesenchymal components. Molecular-targeted therapy of several receptor tyrosine kinases (RTKs) has been reported to be effective in the treatment of various malignant tumors, including carcinosarcoma of several organs. This study aimed to assess the therapeutic potential of targeting RTKs in ECS. Overexpression of RTKs was assessed in 21 ECS cases by immunohistochemistry (IHC). Positively stained cases were further examined for RTK gene mutations and amplifications by direct sequencing analysis and fluorescence in situ hybridization. In epithelial components, KIT, platelet-derived growth factor receptor (PDGFR)A, PDGFRB, MET, epidermal growth factor receptor (EGFR) and HER-2 were overexpressed in 1 (4.8%), 1 (4.8%), 0 (0%), 11 (52.4%), 13 (61.9%) and 2 (9.5%) cases, respectively. In the mesenchymal components the corresponding numbers of cases were 2 (9.5%), 2 (9.5%), 0 (0%), 12 (57.1%), 11 (52.4%) and 0 (0%). No mutations in the c-kit, PDGFRA and c-met genes were found. Among 19 EGFR-positive tumors, 2 had EGFR missense mutations (T790A, exon 20) only in the mesenchymal component. Gene amplification or high polysomy of c-kit, PDGFRA, c-met and EGFR was observed in 1 (33.3%), 0 (0%), 3 (18.8%) and 10 (52.6%) cases, respectively. In conclusion, various RTKs, particularly MET and EGFR were overexpressed in ECSs suggesting that molecular-targeted therapies directed to MET, EGFR or other RTKs may be effective in inhibiting the growth or progression of the epithelial and/or mesenchymal component of ECS.

Carcinosarcoma of the pleura and lung metastasized from a poorly differentiated squamous cell carcinoma of the esophagus

Transformation of a poorly differentiated squamous cell carcinoma (SCC) of the esophagus into a âcarcinosarcomaâ of the pleura and lung has never been reported and its histogenetic origin is still debated. A 48-year-old man was admitted due to progressive dysphagia and a weight loss of 5 kilograms within 2 months. Upper gastrointestinal panendoscopic biopsy revealed poorly differentiated SCC of thoracic esophagus, upper third, T4N1M1a, stage IVa. He received concurrent chemoradiotherapy (CCRT). About 9 months later, rapid progression of lung metastases and pleural effusion were found. According to the histopathological and immunohistochemical stain results, carcinosarcoma was diagnosed. Palliative therapy was given and the patient eventually died of the disease 9 months after SCC of the thoracic esophagus was diagnosed and one month after carcinosarcoma of the pleura and lung were confirmed.

Endoscopic polypectomy: A promising therapeutic choice for esophageal carcinosarcoma

Esophageal carcinosarcoma is a rare malignant tumor composing of both carcinomatous and sarcomatous elements. Endoscopic therapy is less invasive and may represent an alternative to esophagectomy for superficial esophageal carcinosarcoma. Here, we report a 61-year-old male who was diagnosed as esophageal carcinosarcoma and underwent endoscopic polypectomy with well tolerance and favorable prognosis. We also present a brief review of the literature.

Evidence for colorectal sarcomatoid carcinoma arising from tubulovillous adenoma

Sarcomatoid carcinomas of the colorectum are rare tumors that display both malignant epithelial and stromal components. Clinically, they are aggressive tumors with early metastasis. Due to their infrequent occurrence, the pathogenesis is poorly understood. We report a case of a 52-year-old woman who presented with a rectal mass and intermittent hematochezia. Superficial biopsies during colonoscopy revealed a tubulovillous adenoma with high-grade dysplasia. Endoscopic ultrasonography confirmed an invasive nature of the mass, and deeper biopsies revealed the presence of neoplasm with mixed histological components. The surgically-excised specimen demonstrated the presence of poorly differentiated spindle cells underneath the tubulovillous adenoma and an intermediate stage of invasive adenocarcinoma. Based on the histological appearance and immunohistochemical studies, a diagnosis of sarcomatoid carcinoma was made. Only nine cases of sarcomatoid carcinomas of the colorectum have been reported to date. As a result, the terminology and pathogenesis of sarcomatoid carcinoma remain speculative. To the best of our knowledge, this is the first report of co-existence of sarcomatoid carcinoma and invasive adenocarcinoma with tubulovillous adenoma; all stages represented within the same tumor. This observation supports the “monoclonal theory” of pathogenesis with an adenoma-sarcoma progression with or without an intermediate stage of carcinoma.

Endoscopic treatment of pseudosarcomatous squamous carcinoma of the esophagus: case report and personal experience

Spindle cell (or pseudosarcomatous) squamous carcinoma (PSC) is a rare malignant neoplasm of the esophagus, potentially capable of causing lymph node and distant metastases. Indications for surgery are the same as for squamous cell carcinoma (SCC) of the esophagus. The aims of this paper were to report a case of endoscopically treated PSC and to review our experience of surgically-treated patients with PSC in order to identify patients potentially suitable for endoscopic treatment. In our series of 4,460 patients with carcinoma of the esophagus observed between 1980 and 2003, 28 (0.6%) had the histological features of PSC. One had a PSC histologically confirmed (8cm-long polyp with a 3cm-large base) and endoscopically treated for high surgical risk. The patient had a close follow-up with endoscopic biopsies and ultrasonography with no local recurrence at 3 years. The overall survival rate was 22% for PSC and 17% for SCC (P = n.s.); after 5 years, the survival rates were 22% and 13%, respectively (P = n.s.). In our opinion the limited tendency to parietal infiltration and the good chance of disclosure in an early stage with endoscopic ultrasonography, justify non-surgical solutions in patients with a high surgical risk, possibly associated with adjuvant chemo- and radiotherapy since lymph node involvement is reported in 50% of cases. The limited number of patients with PSC involved in the present series prevent any significant statistical comparisons between the different groups, but the survival rates were roughly the same in the nonsurgical curative therapy as in the curative resection group, while the chances of survival were significantly lower in patients given palliative surgery and or non-curative treatments (P < 0.05).

Esophageal carcinosarcoma with basaloid squamous carcinoma and rhabdomyosarcoma components with TP53 mutation

Carcinosarcoma of the esophagus is a rare tumor with a distinct pathological entity having squamous cell carcinoma as the most described carcinomatous component. This paper reports the first case of carcinosarcoma of the esophagus that showed predominant basaloid squamous carcinoma component in addition to squamous cell carcinoma and poorly differentiated carcinoma and sarcoma component. A 64-year-old male patient consulted for dysphasia and chest pain was examined and found to have gastrointestinal fiber-endoscope and a polypoid growth in the lower third of the esophagus. Partial esophagectomy was performed and the excised tumor showed histological features of carcinosarcoma with heterogeneous carcinomatous components with dominance of basaloid squamous carcinoma and minority of squamous cell carcinoma, poorly differentiated carcinoma, and sarcomatous component, immunohistochemically proven to be rhabdomyosarcoma. Immunohistochemical study and TP53 mutation analysis was carried out to explain the histogenesis of this rare tumor. The distinct immunohistochemical profiles of the carcinomatous and sarcomatous components suggested the possibility of transition from a carcinomatous to a sarcomatous component. The similar TP53 mutation in the carcinomatous and sarcomatous component suggested each of these components had the same origin, that is, the tumor was monoclonal in origin.

Carcinosarcoma of the esophagus characterized by myoepithelial and ductal differentiations

We report a case of carcinosarcoma of the esophagus characterized by ductal and myoepithelial differentiation. A 61-year-old man was operated on for a polypoid tumor of the distal esophagus. Histologically, this tumor was composed of ductal structures and sarcomatous spindle cells surrounding the ducts at the central area of the tumor. The tumor was also composed of squamous cell and basaloid carcinoma in the periphery. Immunohistochemically, a few spindle cells surrounding the ductal structures showed immunopositivity for alpha-smooth muscle actin and S-100 protein. Electron microscopy revealed that the spindle cells had tonofilament and pinocytic vesicles in the cytoplasm, and basal lamina adjacent to the cytoplasmic membrane. Both of the results strongly supported the suggestion that the spindle cells may be myoepithelial cells. Basaloid carcinoma showed a gradual transition to chondrosarcomatous cells producing the matrix, which had both immunopositivities for S-100 protein and cytokeratin. Therefore, chondrosarcomatous cells may be derived from carcinoma cells. The histogenesis of this tumor may be associated with a totipotent stem cell of esophageal mucosa, which has the potential to differentiate into squamous cells, ductal cells or myoepithelial cells.

A case of esophageal sarcomatoid carcinoma with molecular evidence of a monoclonal origin

A case of polypoid tumor of the esophagus consisting of a sarcomatous tumor partly covered with superficial squamous cell carcinoma is described. The sarcomatous component consisted of anaplastic spindle and pleomorphic tumor cells that mimicked malignant fibrous histiocytoma (MFH). Both the sarcomatous and carcinomatous components were positive for p53 immunohistochemically. Further molecular analysis revealed that the two components had the same somatic mutation in the p53 gene. These results suggest a monoclonal origin of this biphasic tumor.

Double sarcomatoid carcinomas of the oesophagus

Sarcomatoid carcinoma of the oesophagus is uncommon. A case of double sarcomatoid carcinomas was identified in the oesophagus of a 48-year-old man. This is the fourth case of multiple primary sarcomatoid carcinomas of the oesophagus and the first case with detailed pathological features presented. The clinicopathological features of multiple primary tumours and sarcomatoid carcinoma of the oesophagus are also reviewed.

Spindle cell carcinoma of the parotid gland

Spindle cell carcinomas of the salivary gland are extremely rare, with only a few cases having been previously reported. We present a 55-year-old man with a rapidly enlarging mass in the left parotid gland. Despite radical surgery, the tumour recurred, and led to death 11 months later. Histopathologically, the tumour was composed of two components, a squamous cell carcinoma component and a spindle cell sarcomatoid component. A diagnosis of primary spindle cell carcinoma of the parotid gland was made. Immunohistochemical studies revealed keratin positivity and vimentin negativity in the squamous cell carcinoma component: the spindle cell sarcomatoid component was positive for vimentin and negative for keratin, but showed focal positivity for epithelial membrane antigen. The origin of the sarcomatoid component and the differential diagnosis from malignant mixed tumours are discussed.

Carcinosarcoma in Barrett's oesophagus: a case report with immunohistological examination

A case of a carcinosarcoma which developed in a Barrett's oesophagus is presented. The tumour consisted of an adenocarcinoma and a spindle cell sarcoma. Immunohistological examinations demonstrated vimentin positivity in the sarcomatous portion with a negative reaction for keratin. Immunohistological and histological findings did not rule out the possibility of a double or collision tumour in this case.

Carcinosarcoma of the oesophagus with rhabdomyoblastic differentiation

We report a case of oesophageal carcinosarcoma with prominent rhabdomyoblastic differentiation. Immunohistochemically, the rhabdomyblasts were mainly reactive to vimentin, cytokeratin, desmin, muscle-specific actin, myosin, and myoglobin, and were surrounded by laminin and type IV collagen-positive basement membranes. The tumour had dual differentiation, carcinomatous and sarcomatous, but also showed evident features of transition between the two components; suggesting a common origin. An epithelial-mesenchymal conversion could be the pathogenetic mechanism involved in the histogenesis of this lesion. The word carcinosarcoma, from a descriptive point of view, seems the most suitable to describe a tumour composed of both carcinomatous and true sarcomatous elements.

Carcinosarcoma of the esophagus: a report of two cases

Among 137 cases of esophageal neoplasms surgically treated at Kobe City General Hospital from 1983 to 1990, there were two patients with a huge polypoid lesion identified as carcinosarcoma by light microscopic examination, both of whom underwent radical resection and esophagogastrostomy. Microscopic examination of the resected specimens revealed the tumors to be composed of carcinomatous and sarcomatous elements. Additional immunohistochemical examination disclosed keratin-positive cells in the carcinomatous element and vimentin-positive cells in the sarcomatous element. In case 1, keratin-positive cells were also found in the sarcomatous element, which suggested that the sarcomatous cells were derived from epithelial cells. Despite the huge size of the tumors, the depth of invasion to the esophageal wall was limited to the mucosal layer in case 1 and the submucosal layer in case 2, and there has been no evidence of recurrence in either case since surgery.

Deceptive bizarre stromal cells in polyps and ulcers of the gastrointestinal tract

The clinical and pathologic features of 33 pseudomalignant lesions of the gastrointestinal tract with bizarre stromal cells are reported. Deceptive histologic changes were identified in ulcers of seven patients and in inflammatory polyps of 26. A misdiagnosis of malignant neoplasm was made in six of the 33 patients (three polyps and three ulcers). A history of gastrointestinal bleeding and/or inflammatory bowel disease was common. The bizarre stromal cells were usually distributed beneath the ulcerated mucosa or within granulation tissue. They stained strongly for vimentin in 20 of 23 cases. Some of the bizarre cells also stained for muscle specific actin (seven of 23 cases). The cells appear to be reactive fibroblasts or myofibroblasts. Follow-up information obtained on 24 of the 33 patients (including four of the six cases initially diagnosed as malignant) revealed 22 patients to be alive without evidence of a malignant neoplasm (average follow-up, 13 months). Two patients died of other causes. Correct recognition of these bizarre stromal cells in gastrointestinal ulcers and inflammatory polyps will prevent a potentially serious diagnostic pitfall.

Association of Adenocarcinoma and Leiomyosarcoma of the Sigmoid Colon. A Case Report

Malignant tumors of the gastro-intestinal tract showing both carcinomatous and sarcomatous components are rare. Very few cases were described in the stomach and only one case in the colon. We describe a second case of a tumor of the sigmoid colon showing adenorcarcinoma intermigled with leiomyosarcoma elements.

Fibrovascular polyp of the oesophagus

Fibrovascular polyps of the oesophagus are rare. Despite this, they provoke considerable interest because of their often dramatic presentation, and their potential for lethal complications. When the diagnosis is entertained, endoscopic or radiological confirmation is usually easily obtained and local excision is curative. An adult patient is described who presented after partial regurgitation of a 10 cm polyp. In view of the size of the lesion and its proximal attachment, endoscopic polypectomy was undertaken. The diagnostic pitfalls and therapeutic options in this unusual condition are discussed.

Squamous cell carcinoma of the esophagus with cartilaginous metaplasia at metastatic lesions

Subdermal metastatic nodules in a 62-year old male patient with esophageal carcinoma contained both carcinomatous and chondroid areas. The carcinomatous areas showed the histology of poorly differentiated squamous cell carcinoma, and light microscopically an apparent transition could be traced from carcinomatous cells to chondroid cells. In the chondroid cells, the characteristics of chondrocytes were demonstrated by light microscopic, electron microscopic, histochemical and immunohistochemical studies, although nuclear atypism was evident, suggesting their malignancy. Furthermore, immunohistochemical studies showed that some chondroid cells contained both keratin proteins and squamous cell carcinoma antigen, which were also found in the carcinomatous cells. These findings together with the light microscopic observations suggest that chondroid cells are derived from squamous cell carcinoma cells.

Polypoid squamous cell carcinoma of the larynx. An immunohistochemical study for ras p21 and cytokeratin

Polypoid squamous cell carcinoma of the larynx consists of two components, namely, squamous cell carcinoma and sarcomatoid spindle cells. To further investigate the histogenesis of the spindle cell component, we studied two cases of polypoid squamous cell carcinoma of the larynx by immunohistochemistry and ultrastructural analysis. Positive staining for ras oncogene p21 and cytokeratin was demonstrated in both squamous cell carcinoma and spindle cell component. Only the latter component was positive for vimentin. Electron microscopic examination showed well-developed desmosomes in spindle cells. These results suggest that the spindle cell component is epithelial in origin and malignantly neoplastic; it originates from mesenchymal metaplasia or squamous cell carcinoma.

Morphological heterogeneity of esophageal carcinoma

To clarify the morphological heterogeneity of esophageal carcinoma, the adenocarcinomatous, basaloid, and sarcoma-like components of 178 esophageal carcinomas were studied with regard to histopathology, mucin histochemistry, immunohistochemistry, and ultrastructure. Adenocarcinomatous components with mucicarminophilic cells and/or glandular structures, basaloid components, and sarcoma-like components were found in 55 lesions (30.9%), 17 lesions (9.3%), and five lesions (2.8%) respectively. Carcinoembryonic antigen staining was positive in 52 lesions (29.2%), secretory component staining was positive in 15 (8.4%), and lactoferrin staining was positive in 12 (6.7%). Eight intraepithelial carcinomas were found to have no adenocarcinomatous components, and two intramucosal carcinomas had adenocarcinomatous components in the invasive portions. These findings strongly suggest that the adenocarcinomatous components do not arise from the ductal epithelium, but occur during the process of invasion. There were no significant clinicopathological differences between the carcinomas with adenocarcinomatous components and those without. Ultrastructurally, the adenocarcinomatous components were seen to possess intracellular microcysts, intercellular lumina, and bundles of tonofilaments, having features of both glandular and squamous epithelia. On the basis of the concept that the basaloid components are histological variants of squamous cell carcinoma and that sarcoma-like components arise from mesenchymal metaplasia of squamous cell carcinoma, it is possible that the three components may originate from the squamous component. The present study thus demonstrated a high incidence of histological variation among esophageal carcinomas.

Pseudosarcoma of the oesophagus

The presentation, histology and management of a pseudosarcoma (or polypoid carcinoma) of the oesophagus are presented. Historical and modern theories of pathogenesis are discussed. Though rare, ENT surgeons should be aware of these tumours, as patients with such tumours present early and potentially have a much better prognosis than those with the more common oesophageal malignancies.

Intermediate filament proteins in spindle cell carcinoma of the larynx and tongue

In an analysis of intermediate filament protein expression of spindle cell carcinoma, a variant of squamous cell carcinoma, occurring in larynx and tongue, vimentin positivity was found in sarcomatoid areas in 12 of 13 patients. Scattered expression of keratin was observed in sarcomatoid areas in tumours of 10 patients. However, large parts of sarcomatoid areas of such tumours were negative for keratin. Overlying dysplastic epithelium and squamous cell carcinoma components were positive for keratin. In a number of cases there was a strong indication of co-expression of keratin and vimentin in parts of cells that, on histological grounds, belong to sarcomatoid areas or to cells in the interface between carcinoma and spindle cell area. The use of keratin and vimentin type intermediate filament antibodies could be of great help for the correct classification of these tumours.

Pulmonary carcinomas with a sarcomatoid element: an immunocytochemical and ultrastructural analysis

Eight primary carcinomas of the lung with a prominent spindle-cell sarcomatoid component were studied by immunocytochemical staining and electron microscopy. The eight tumors were indistinguishable by conventional light microscopy, with the exception of one unusual neoplasm that followed multiple pathways of differentiation with elements of squamous cell carcinoma, rhabdomyosarcoma, chondrosarcoma, and an undifferentiated spindle-cell population. Reticulin fiber production by individual spindle cells and a sharp demarcation of the carcinomatous and sarcomatoid domains by light microscopy were not useful differentiating features. Three of the eight tumors exhibited keratin expression in both the carcinomatous and spindle-cell components. Both immunocytochemical and electron microscopic analyses were required to detect epithelial differentiation, as in one case keratin was identified only by immunocytochemical staining and in another only by ultrastructural examination. Epithelial differentiation was undetectable in the sarcomatoid component of five tumors, and in one case immunoreactive myoglobin was identified in spindle cells; skeletal muscle differentiation was confirmed ultrastructurally. We propose that pulmonary carcinomas exhibiting evidence of epithelial differentiation in a sarcomatoid component be termed spindle-cell carcinomas and that those biphasic tumors exhibiting mesenchymal differentiation into specific tissues, such as neoplastic bone, cartilage, or striated muscle, or lacking epithelial differentiation by light microscopy, immunocytochemistry, and electron microscopy be classified as carcinosarcomas. This distinction may ultimately be unnecessary, because these two tumors may represent different points along a morphologic and biologic continuum.

Esophageal carcinoma with prominent spindle cells

Eight cases of esophageal carcinoma with prominent spindle cells (carcinosarcoma or pseudosarcoma) were studied using the avidin-biotin immunoperoxidase method and monoclonal antibodies to various keratins and vimentin. In all eight cases positive immunoreactivity for keratin was found in carcinomatous areas and for vimentin, in the spindle cells. It is interesting that five cases demonstrated focal immunoreactivity to keratin in the spindle cell component. Trace positivity to vimentin was seen in the carcinomatous areas in one case. These findings are consistent with the hypothesis that esophageal carcinoma with prominent spindle cells is of epithelial origin and may represent a morphologic variant of squamous cell carcinoma.

Polypoid tumor of the esophagus

Five cases of an uncommon esophageal tumor consisting of a mucosal squamous cell carcinoma that surrounds a polypoid mass of spindle cells were examined. The spindle cell component was composed of elongated cells with blunt nuclei, admixed with multinucleated giant cells. Reticulin fibers enveloped individual cells, and abundant collagen was present. Thirteen to 69 mitotic figures occurred per 10 high-power fields. Electron microscopy showed dilated cisternae of rough endoplasmic reticulum and peripheral intermediate filaments within the cytoplasm. Intermediate-type junctions (zonulae adherens) and subplasmalemmal linear densities connected some cells. No tonofibrillar bundles or desmosomes (maculae adherens) were present. Immunoperoxidase stains detected no keratin in the spindle cells. Alpha-1-antichymotrypsin and alpha-1-antitrypsin were in the spindle cells in five of five and three of five cases, respectively. The absence of desmosomes, tonofibrillar bundles, and keratin and the presence of alpha-1-antitrypsin and alpha-1-antichymotrypsin favor fibrohistiocytic differentiation of the spindle cell component.

Spindle cell carcinoma of the uterus

A case of spindle cell carcinoma of the uterus in a 56-year-old woman is reported. Microscopically, it showed an intimate admixture of epithelial and sarcomatous elements. The epithelial nature, especially the squamous cell nature, in sarcomatous areas was indicated by immunoreactivity for keratin and ultrastructural characters, such as bundles of tonofilaments and some cell junctions, while the tumor cells in these areas were also vimentin-positive. Furthermore, ultrastructural study and immunostaining for actin demonstrated myofilaments in tumor cells in both tumor nests and sarcomatous areas. This may impart the high degree of invasiveness of spindle cell carcinoma.

Expression of epithelial markers in sarcomatoid carcinoma: an immunohistochemical study

Thirty-four cases of sarcomatoid carcinoma with minimal epithelial components (SC) and six cases of sarcomatous tumour without any epithelial component (ST) in various organs were studied by the immunoperoxidase technique for the expression of epithelial markers, cytokeratins and epithelial membrane antigen (EMA). Employing antibodies against both high and low molecular weight cytokeratins, sarcomatoid components in 30 examples of SC were stained positively. Epithelial membrane antigen was demonstrated in 19 out of 34 SC. The positive cells for epithelial markers within sarcomatoid components in some cases of SC, which were regarded as originating from squamous cell carcinoma, tended to be seen less frequently than in the tumours derived from adenocarcinoma or transitional cell carcinoma. In six cases of ST, stain for EMA was negative and stain for cytokeratins was positive in three examples. The immunohistochemical examination of epithelial markers in the tumours of these types may be of value in differentiating these tumours from true sarcomas.

Carcinosarcoma of the colon. Report of a unique case with light and immunohistochemical studies

A unique case of carcinosarcoma of the colon is reported. The tumor invaded the bowel wall deeply, metastasized widely, resisted multi-agent chemotherapy, and caused the patient's death 4 years later. The tumor was composed of adenosquamous carcinoma admixed with sarcoma showing osseous, cartilaginous, and nonspecific spindle-cell differentiation. Although carcinoembryonic antigen appeared limited to carcinoma cells, cytokeratin immunoreactivity was observed in both carcinoma and sarcoma cells. Like carcinosarcomas at other body sites, the finding of cytokeratin in sarcoma cells supports partial epithelial differentiation in this component, likely retained from carcinoma precursor cells.

Pulmonary blastoma, carcinosarcoma and spindle-cell carcinoma: an immunohistochemical study of keratin intermediate filaments

We have examined 18 primary malignant lung tumours categorized as either carcinosarcoma, blastoma or spindle-cell carcinoma according to accepted criteria. Two monoclonal antibodies to keratins, CAM 5.2 and LP 34, were used to determine whether the non-epithelial or spindle-cell components of each tumour showed evidence of keratin expression. By this means the epithelial nature of the five tumours classified as spindle-cell carcinomas was confirmed. In all four pulmonary blastomas and in five of nine carcinosarcomas, the sarcomatous elements failed to stain for keratin but in the remaining four carcinosarcomas there was focal staining. The histogenesis of these tumours is discussed and it is suggested that the sarcomatous component of a carcinosarcoma may be derived from malignant epithelial cells by a process of mesenchymal metaplasia with a switch in intermediate filament type. It remains uncertain whether blastomas are derived from both endoderm and mesoderm, or from either one of these tissues, with one component representing complete metaplastic transformation.

Spindle cell squamous carcinoma of the larynx. Clinico-pathological study of seven cases

The clinical and pathological findings of seven cases of spindle cell squamous carcinoma of the larynx are reported. The histogenesis, biological behaviour and appropriate therapy of neoplasm are discussed.

Antibodies to intermediate filament proteins in the diagnosis and classification of human tumors

Immunohistochemistry of intermediate filaments (IF) is a new and important way to evaluate the epithelial, mesenchymal, muscular, glial, or neural differentiation in tumors. This is based on the stable cell-type-specific expression of IF proteins in normal and neoplastic tissues. Immunohistochemical studies with antibodies to intermediate filaments have also given new perspectives in the histogenesis and biologic nature of many tumors. This article reviews both the recent findings and the authors' experience in the use of intermediate filament antibodies in tumor diagnosis and classification.