Stem cell carcinoma of the colon and rectum. Report of two cases and review of the literature

Treatment paradigm and prognostic factor analyses of rectal squamous cell carcinoma

Background

Rectal squamous cell carcinoma (rSCC) is a rare pathological subtype of rectal cancer. There is no consensus on the treatment paradigm for patients with rSCC. This study aimed to provide a paradigm for clinical treatment and develop a prognostic nomogram.

Methods

Patients diagnosed with rSCC between 2010 and 2019 were identified in the Surveillance, Epidemiology, and End Results (SEER) database. According to the TNM staging system, Kaplan-Meier (K-M) survival analysis was used to identify the survival benefits of different treatments in patients with rSCC. The Cox regression method was used to identify independent prognostic risk factors. Nomograms were evaluated by Harrell's concordance index (C-index), calibration curves, decision curve analysis (DCA) and K-M curves.

Results

Data for 463 patients with rSCC were extracted from the SEER database. Survival analysis showed that there was no significant difference in median cancer-specific survival (CSS) among patients with TNM stage 1 rSCC treated with radiotherapy (RT), chemoradiotherapy (CRT) or surgery (P = 0.285). In TNM stage 2 patients, there was a significant difference in median CSS among those treated with surgery (49.5 months), RT (24 months), and CRT (63 months) (P = 0.003). In TNM stage 3 patients, there was a significant difference in median CSS among those treated with CRT (58 months), CRT plus surgery (56 months) and no treatment (9.5 months) (P < 0.001). In TNM stage 4 patients, there was no significant difference in median CSS among those treated with CRT, chemotherapy (CT), CRT plus surgery and no treatment (P = 0.122). Cox regression analysis showed that age, marital status, T stage, N stage, M stage, PNI, tumor size, RT, CT, and surgery were independent risk factors for CSS. The 1-, 3-, and 5-year C-indexes were 0.877, 0.781, and 0.767, respectively. The calibration curve showed that the model had excellent calibration. The DCA curve showed that the model had excellent clinical application value.

Conclusion

RT or surgery is recommended for patients with stage 1 rSCC, and CRT is recommended for patients with stage 2, and stage 3 rSCC. Age, marital status, T stage, N stage, M stage, PNI, tumor size, RT, CT, and surgery are independent risk factors for CSS in patients with rSCC. The model based on the above independent risk factors has excellent prediction efficiency.

Primary Squamous Cell Carcinoma of the Sigmoid Revealed by Acute Intestinal Occlusion in Moroccan Young Male Patient: A Case Report and Literature Review

Primary colorectal squamous cell carcinoma (SCC) is an extremely rare subtype of colon cancer, with an incidence of less than 1% of colorectal malignancies. We report a case of a 40-year-old male patient admitted to the emergency department with symptoms of acute intestinal obstruction. Histopathological evaluation of colonoscopic biopsies revealed squamous cell carcinoma. A sigmoidectomy was performed. In order to enrich the medical literature, we add our case to the collection of colorectal squamous cell carcinoma cases by analyzing and summarizing the clinical, pathological, and therapeutic features of this rare entity.

A primary squamous cell carcinoma of the sigmoid colon in a young patient: A case report and literature review

Colon cancer is among the most common types of cancer with adenocarcinomas being the most common type. Herein we report a young patient who presented with primary colonic squamous cell carcinoma without risk factors. To the best of our knowledge, this is the youngest patient with such diagnosis worldwide.

Small-cell neuroendocrine carcinoma of the rectum - a rare tumor type with poor prognosis: A case report and review of literature

BACKGROUND

Small-cell neuroendocrine carcinoma (SNEC) of the rectum is a rare tumor associated with poor prognosis.

CASE SUMMARY

We report a case of a 77-year-old male who came into our hospital because of blood with his stool. An endoscopy revealed a cauliflower-like neoplasm in his rectum. Imaging examination showed that the lesion in the upper rectum was likely rectal cancer, and there was no evidence of metastasis. The patient was treated with surgery. Pathological examination confirmed SNEC of the rectum and an R0 resection was achieved. However, 1 mo after the operation, the patient developed intestinal and ureteral obstructions due to peritoneal metastases. Finally, the patient died from renal failure.

CONCLUSION

SNEC of the rectum is a high-grade carcinoma with an aggressive phenotype, and surgery should be cautiously considered.

Primary colonic squamous cell carcinoma: a case report and review of the literature

Colonic squamous cell carcinoma is extremely rare, with no clear pathogenesis. It usually presents as an emergency. We present the surgical management of a descending colon squamous cell carcinoma, together with a review of the available cases of colonic squamous cell carcinoma in the literature. A 69-year-old woman presented with a palpable mass and abdominal pain. She underwent ultrasound and colonoscopy, which revealed a large obstructing mass at the descending colon, the biopsies of which were not diagnostic. Unfortunately, she was readmitted with bowel obstruction and underwent extended right hemicolectomy with en-bloc excision of attached small bowel and omentum because of local mass expansion. Histopathological analysis demonstrated squamous cell carcinoma with lymph node metastases. Palliative chemotherapy followed, owing to liver and peritoneal deposits. Sixty-six cases of colonic squamous cell carcinoma have been reported in the literature. The most common location is the right colon. Most cases present at a late stage. Several theories for the pathogenesis of colonic squamous cell carcinoma have been reported; the most popular is the squamous transformation of a pluripotent stem cell.

Primary Squamous Cell Carcinoma of Colon and Rectum: A Systematic Review of the Literature

Background - Objective: Primary colorectal squamous cell carcinoma is an extremely rare neoplasm with an incidence of 0.1 to 0.25 per 1,000 diagnosed colorectal carcinomas.The objective of this study was to evaluate its biological behavior and highlight the role of a surgical approach for its management.Methods: PubMed and Cohrane databases were independently searched (last search: April 10th, 2020) for articles concerning colorectal squamous cell carcinoma in adult population.Results: Seventy-one studies met predefined inclusion criteria and involved 99 patients (54.5% females) with an age of 56.98 ± 12.19 years (mean ± SD). The most frequent site of occurrence was the rectum (63.5%). Open surgery was conducted at 95% of patients, while 21.4% and 30.3% received neoadjuvant and adjuvant therapy respectively.Postoperative complications were developed in 31.3% of patients, while 6.1% died withing the first month following operation. Five-years survival rate was 49.5% (95% CI: 33.7%-63.4%). Female sex (HR: 0.24; 95% CI: 0.11-0.54; p-value: 0.001) and presence of postoperative complications (HR: 4.10; 95%CI: 1.47-1.46; p-value: 0.007) significantly affected the survival.Conclusions: Colorectal Squamous Cell Carcinoma is a rare tumor with an aggressive behavior. Surgery is the standard of treatment for the colontumors, while the role of chemoradiotherapy is promising especially for rectal tumors. Further clinical trials are necessary to determine the preferred treatment approach.

[Primary squamous cell carcinoma of the colon: about a case]

Primary squamous cell carcinoma (SCC) of the colon is an exceptional tumor. Less than 150 cases have been reported in the literature up to the year 2014. In addition to its rarity, it is distinguished by its frequent association with other digestive neoplasias. We report the case of a 54-year old patient with primary SCC of the colon. In the light of this case study, we will discuss the anatomo-clinical and therapeutic features as well as the etiopathogenic assumptions of this unusual entity.

Hypercalcemia of Malignancy and Colorectal Cancer

Our aim is to describe the association between colorectal cancer (CRC) and humoral hypercalcemia of malignancy (HHM). Causes of hypercalcemia of malignancy include parathyroid hormone-related peptide (PTHrP) secretion, local osteolysis, calcitriol production and ectopic parathyroid hormone (PTH) secretion. Hypercalcemia of malignancy in patients with CRCs is a rare scenario. A patient with anal squamous cell carcinoma was admitted with hypercalcemia, suppressed PTH and hypophosphatemia. He was found to have metastatic anal squamous cell carcinoma to the liver. Further evaluation revealed elevated PTHrP and 1,25-dihydroxyvitamin D and low 25-hydroxyvitamin D. Over a 5-month course, the hypercalcemia responded poorly to bisphosphonates, transiently to prednisone, but showed marked improvement with chemotherapy. A review of English language publications in Pubmed and a reference search of retrieved articles revealed 29 cases of CRC causing PTHrP-mediated hypercalcemia. Most patients were middle-aged men (mean ± SD: 56.7 ± 13.4 years), with advanced metastatic cancer (85% with hepatic metastasis) and severe hypercalcemia (mean ± SD: 15.6 ± 1.9 mg/dL, 62% with Ca > 14). This condition is associated with high mortality (79%) and short survival (median 54.5 days, CI: 21 - 168). Despite being uncommon, HHM (PTHrP-mediated) should be considered in patients with metastatic CRC presenting with hypercalcemia. Clinicians should be aware that combined etiologies may be present, particularly in cases of resistant hypercalcemia. Treatment of the underlying malignancy is essential for calcium control.

Synchronous Small Cell Neuroendocrine Carcinoma and Adenocarcinoma of the Colon: A Link for Common Stem Cell Origin?

Synchronous carcinomas have been recognized for over a century, with synchronous primary adenocarcinoma of the colon reported to range from 2-11% of cases involving this type of malignancy. Small cell carcinomas occur frequently with colorectal adenomas; however, despite these reports and a known adenoma-to-carcinoma sequence, scarce literature exists on synchronous colorectal adenocarcinoma and small cell carcinomas. We present a rare cancer of synchronous small cell neuroendocrine carcinomas and discuss a possible link between these two cancers.

Colorectal neuroendocrine carcinomas and adenocarcinomas share oncogenic pathways. A clinico-pathologic study of 12 cases

OBJECTIVE

Neuroendocrine carcinomas (NECs) are rare neoplasms with an increasing incidence. Oncogenetic pathways of colorectal NEC are still poorly understood, and no treatment standards are available for these rare tumors.

METHODS

We analyzed retrospectively the clinical records and histology of 12 patients with colorectal NEC. KRAS and BRAF mutations were investigated after the dissection of exoendocrine and neuroendocrine components. ALK alterations and EML4-ALK transcripts were detected by in-situ hybridization and determination of fusion transcripts, respectively.

RESULTS

At the time of diagnosis, the mean age of the patients was 60 years (40-79) and 10 patients had synchronous metastases. A transient response occurred in two patients and one patient treated with cisplatin-etoposide or fluoropyrimidine-oxaliplatin, respectively. Tumor progression-related death occurred in 11 of 12 patients. Ten tumors contained an exocrine component, accounting for 5-70% of the tumor, and the other two contained an amphicrine component. BRAF/KRAS mutations were found in six of 10 tumors, corresponding to BRAF(V600E) (n=2) or KRAS(G12D) (n=2), KRAS(G12V) or KRAS(G13D). DNA was obtained from both exocrine and endocrine components in seven cases, and the BRAF/KRAS status was identical in all cases. Split of the ALK locus was detected in a minority of tumor cells in two of eight cases, but EML4-ALK transcripts were absent.

CONCLUSION

The association of an exocrine component in all cases and the similar profile of BRAF/KRAS mutations indicate that colorectal NEC may correspond to a high-grade transformation of colorectal carcinoma. New chemotherapy regimens using targeted therapies should be assessed in these tumors.

Colorectal small cell carcinoma in ulcerative colitis with identical rare p53 gene mutation to associated adenocarcinoma and dysplasia

Colorectal small cell carcinomas (SCCs) are rare tumors and are infrequently associated with ulcerative colitis (UC). We report a case of primary rectal SCC combined with adenocarcinoma arising in left-sided UC. Immunohistochemically, tumor cells were positive for chromogranin A, synaptophysin, and CD56 in the SCC but not in the adenocarcinoma. The patient simultaneously developed multiple lesions of adenocarcinoma and high-grade dysplasia in the sigmoid colon and rectum. To elucidate whether SCC might evolve from multipotential cells in dysplasia and/or adenocarcinoma, we examined the mutational status of TP53 and KRAS. The same clonality of these lesions including SCC was confirmed by the presence of an identical single nucleotide point mutation in TP53. KRAS mutation was not observed in these lesions. Thus, these lesions seem to have developed from the same origin. Long-standing inflammation leading to dysplasia might be responsible for the development of some SCCs in UC particularly when they are combined with dysplasia and/or adenocarcinoma.

Small cell carcinoma in ulcerative colitis--new treatment option: a case report

Background

The most common type of carcinoma associated with ulcerative colitis (UC) is adenocarcinoma. We present a case of primary rectal small cell carcinoma in a patient with a history of UC.

Methods

A 34-year-old male diagnosed with UC for 10 years was not consistent with the usual annual follow-up and presented with mucoid-bloody diarrhea. Colonoscopy revealed a rectal mass 2 cm distant from the anal verge. The patient underwent a total proctocolectomy with preservation of the anal sphincters, construction of an ileal reservoir, anastomosis of the reservoir to the anus (J configuration) and protective loop ileostomy.

Results

Histological examination showed undifferentiated small cell carcinoma.

Conclusions

This is the first case of small cell carcinoma in a background of UC reported to be treated surgically and the patient and has no reccurence 18 months postoperatively.

Primary Submucosal Squamous Cell Carcinoma of the Rectum Diagnosed by Endoscopic Ultrasound: Case Report and Literature Review

Primary colorectal squamous cell carcinoma (SCC) is one of the very rare malignancies of the gastrointestinal tract. The diagnosis cannot be made before ruling out other common primary sites. Using the endoscopic ultrasound (EUS) technique to get a tissue biopsy for submucosal tumors has not been demonstrated as the best diagnostic approach in the literature. Surgery is the gold standard treatment with arising evidence of good efficacy following conventional chemoradiation therapy. A 49-year-old male presented with rectal discomfort. Sigmoidoscopy revealed multiple submucosal masses in the rectosigmoid colon. Mucosal biopsies showed nonspecific inflammation. Subsequently, an EUS with fine needle biopsy was done and established the diagnosis of rectal SCC. There were no other primary sites noticed in the extensive evaluation. The patient chose to be treated only with chemoradiation without surgery. At the time of writing this report he had no evidence of recurrence achieving 2.5 years of survival. EUS is an emerging excellent approach to diagnose submucosal colorectal SCC. This case will add supportive evidence of having a complete response following combining treatment with squamous cell directed chemotherapy and external beam radiotherapy without preceded surgery.

A case of primary combined neuroendocrine carcinoma with squamous cell carcinoma in the upper gingiva

Neuroendocrine carcinoma is a rare neoplasm that occurs widely in various organs and tissues. The biological behavior of this tumor in the oral region remains poorly understood. We encountered an extremely rare case of combined neuroendocrine carcinoma with squamous cell carcinoma, occurring at the buccal gingiva in a 62-year-old woman. Left partial maxillectomy was performed. Histological examinations revealed solid nests with extensive necrosis and nuclear palisading at the periphery. The tumor also showed areas of stratified neoplastic squamous differentiation. Immunohistochemically, tumor nests stained positive for synaptophysin, chromogranin, N-CAM (CD56), and neuron-specific enolase. Strong positivity was seen for K14 and K17 in the squamous component and for K7 in the neuroendocrine component. Both components showed K19 staining. Cells with squamous differentiation and K14 staining occasionally expressed p63. The patient showed no evidence of disease as of 23 months postoperatively. Given the aggressive characteristics of neuroendocrine carcinoma, strict follow-up has been performed.

An unusual case of colonic mixed adenoendocrine carcinoma: collision versus composite tumor. A case report and review of the literature

We report a case of collision tumor of the cecum in a 50-year-old woman and discuss the morphological criteria used for classifying mixed glandular-endocrine neoplasms of the digestive tract in a large series of reported cases. The cecal tumor showed clear geographic polarization, with no admixture or transition of the 2 neoplastic components. A lymph nodal metastatic deposit contained both tumors. Immunohistochemical stainings were consistent with the carcinomatous and carcinoidal nature of the 2 neoplasms, except for a minute area of carcinoembryonic antigen positivity in the carcinoid. A review of the literature shows that many mixed glandular-endocrine tumors of the digestive tract escape precise classification using established morphological criteria. Collision and composite tumors can share common histological and immunohistochemical features, including polyclonal metastases and carcinoembryonic antigen expression in the carcinoidal area. Mixed tumors of the cecum showing a collision-like morphology appear to behave more aggressively than other colonic adenoendocrine carcinomas.

Small Cell Undifferentiated Carcinoma of the Ascending Colon with Rapid Enlargement after Resection: Report of a Case and Review of the Literature

Although adenocarcinoma represents the vast majority of neoplasms of the large intestine, small cell undifferentiated carcinoma (SCUC) also arises from the colorectum. SCUC of the colorectum is highly malignant and shares the similarities in histologic characteristics, behavior, and histochemistry with SCUC of the lung. We report herein a case of SCUC in the ascending colon with rapid enlargement after resection. A 70-year-old male, who presented to a nearby physician with chief complaints of pain in the right lower quadrant, was referred to our hospital. We found a tumor mass that was approximately 15 cm in size in the right lower quadrant. Computed tomography (CT) images showed an irregularly shaped tumor, located inferior to the lower border of the right kidney and in the area of the ascending colon. By colonoscopy, we found a circumferential tumor of the ascending colon. A biopsy indicated it to be SCUC. The patient underwent right hemicolectomy. Two weeks after the resection, we palpated a tumor mass in the same area. The abdominal CT images showed a tumor mass that was approximately 10 cm in size. The tumor rapidly enlarged, and the patient died of multiple organ failure. SCUC is a tumor with a high malignant potential. Radical treatment cannot be achieved by surgical therapy alone and hence further studies of effective adjuvant therapy would be required.

Humoral hypercalcemia complicating adenocarcinoma of the sigmoid colon: report of a case

Humoral hypercalcemia can arise from a variety of malignancies, but its association with primary colorectal carcinoma is rare, with only 20 such cases documented in the English-language literature to date. We report an additional case to clarify the clinicopathologic features of colorectal carcinoma with humoral hypercalcemia. A 54-year-old woman was admitted with symptomatic hypercalcemia of 14.2 mg/dl and multiple hepatic metastases, 2 years after resection of sigmoid colon cancer. The hypercalcemia was caused by the circulating parathyroid hormone-related peptide (PTHrP) produced by poorly differentiated adenocarcinoma in the liver. The PTHrP level on admission was 13.5 pmol/l. Despite systemic chemotherapy, the patient died of disease progression 3 weeks after the humoral hypercalcemia was diagnosed. A review of the 21 reported cases, including ours, suggests that colorectal carcinoma associated with humoral hypercalcemia is characterized by a poorly differentiated tumor with or without squamous or neuroendocrine features, distant metastases, and a dismal prognosis.

Squamous cell carcinoma of the rectum: a case report and review of the literature

Squamous cell carcinoma of the colon and rectum are extremely rare neoplasms. Many questions regarding their histogenesis and biological behaviour remain unanswered. Surgery is the most effective therapy, and adjuvant chemotherapy and radiotherapy should be considered, especially for node-positive patients. We present a patient with squamous cell carcinoma of the middle rectum who underwent abdominoperineal resection and postoperative adjuvant chemotherapy. The pertinent literature is reviewed.

Small cell carcinoma of rectum: A case report

We present a case of a 40-year-old woman with small-cell carcinoma (SCC) of the rectum. She had profuse bleeding in rectum for 5 d. By colonoscopy, polyps were determined in the rectum and biopsies were carried out. Histopathologically, the polyps were adenomatous. Because of the profuse bleeding in rectum, she underwent low anterior resection. After the diagnosis of SCC, she received intravenous chemotherapy with standard doses of siklofosfamid, adriamycin, and vepesid. Nevertheless, intracranial metastases were revealed and she died 6 mo after the operation.

Heterogeneous expression of neuroendocrine marker proteins in human undifferentiated carcinoma of the colon and rectum

The expression of neuroendocrine marker proteins in undifferentiated colorectal cancers has not yet been studied in great detail. Therefore, the survival of 20 patients with small cell undifferentiated colorectal cancers treated at our institution between 1982 and 1997 (0.8% of all operated colorectal carcinomas) was correlated with the extent of neuroendocrine differentiation. Chromogranin A, synaptophysin, syntaxin1, VAMP2, SNAP25, and alpha/beta-SNAP were used as neuroendocrine markers. Based on the degree of immunoreactivity for these marker proteins, tumors were divided into group 0 (<2% cells stained positive for neuroendocrine markers) and group 1 (>2% cells stained positive). Patients were followed up for at least 5 years or until death. Nine of twenty (45%) undifferentiated colorectal tumors expressed neuroendocrine markers (group 1). Only one patient of this group survived 2 years (11%), whereas the 2-year survival rate was 45.4% in group 0. Nine of eleven patients of group 0 were diagnosed in UICC stage I-III, whereas eight of nine tumors with expression of neuroendocrine markers were diagnosed in UICC stage IV (P = 0.002). Our results show that neuroendocrine differentiation is often seen in small cell undifferentiated colorectal cancer. It correlates with a more aggressive course of the disease.

Diagnostic and pathogenetic implications of colorectal carcinomas with multidirectional differentiation: a report of 4 cases

Multidirectional differentiation in colorectal carcinomas is a rare phenomenon. Four cases are reported herein, and their clinical and pathologic characteristics are discussed. Two men and 2 women between the ages of 56 and 76 years who presented with abdominal symptoms are included in this report. Two tumors were located in the right colon, one in the splenic flexure, and one in the descending colon. Distant metastases were evident at presentation in 3 of 4 cases. Histologically, two tumors exhibited neuroendocrine and glandular differentiation; the third tumor was an adenocarcinoma with a sarcomatous component and the fourth tumor showed 3 lines of differentiation (glandular, squamous, and sarcomatoid). In all tumors evaluated, areas of adenocarcinomas were positive for low-molecular weight cytokeratin (CAM 5.2) and mucicarmine, but negative for high-molecular weight cytokeratin (AE3). The squamous cell component was AE3 positive and CAM 5.2 negative. The neuroendocrine component was highlighted by neuroendocrine markers and the sarcomatoid component revealed smooth muscle differentiation. All tumors (except one mucinous tumor) were negative for cytokeratin-20 staining. One patient was on supportive care for terminal metastatic carcinoma, and 2 patients were being treated with adjuvant chemotherapy at the time of this report. Colon carcinoma with multidirectional differentiation is a rare event and may originate from stem cells within the gastrointestinal mucosa, and/or represent the convergence of multiple tumors arising at the same site. This type of tumor should be considered in the differential diagnosis of a bowel biopsy with multiple histopathologic variants.

Paraneoplastic Hypercalcemia in a Patient with Adenosquamous Cancer of the Colon

Hypercalcemia is a well-known manifestation of paraneoplastic syndromes associated with a variety of malignancies. However, colon cancer has only rarely been associated with hypercalcemia of malignancy. We present the case of a patient with recurrent adenosquamous carcinoma of the ascending colon found to have hypercalcemia. The patient is a 76-year-old white woman who initially presented with colon cancer in the cecum and underwent a right hemicolectomy. All lymph nodes and surgical margins were free of tumor. Pathological examination at that time revealed adenosquamous carcinoma of the colon. Eight months later she complained of dizziness, anorexia, and constipation and was found to have a calcium level of 13.6 mg/dL. CT scan revealed a mass measuring 10.5 to 12.7 cm in the right hepatic lobe, and a bone scan was normal. Her intact parathyroid hormone (PTH) level was 6 pg/mL (normal 12–72) and her PTH-related protein (PTHrP) level was 25.7 pmol/L (normal <1.3). She then underwent a hepatic resection. The serum PTH, calcium, and PTHrP levels normalized after resection. Hypercalcemia of malignancy in colon cancer is rare and has an association with adenosquamous histology. The hypercalcemia is attributed to PTHrP, and here we demonstrate this in the serum and tumor specimens. The effects of PTHrP are shown to be short-lived postoperatively. We find only 14 other cases in the literature of hypercalcemia related to a colonic neoplasm, and this is the only patient reported to be surviving. The diagnosis of a paraneoplastic syndrome mediated via PTHrP should be considered when hypercalcemia is encountered in the setting of metastatic colon carcinoma.

Squamous cell carcinoma of the colon with an elevated serum squamous cell carcinoma antigen responding to combination chemotherapy

Primary squamous cell colorectal carcinomas are uncommon, and their characteristics are not well known. They seem to occur most commonly in the fifth decade of life with a slight predominance for men. The most commonly reported anatomic locations are the rectum and the proximal colon. Clinical features and common diagnostic methods do not easily differentiate squamous cell colorectal carcinomas from adenocarcinomas. Because of their extremely rare occurrence, it is difficult to study their natural course, clinical behavior, and response to therapy. This report presents the case of a pure squamous cell colorectal cancer and provides a brief review of the literature, which includes 60 previously published cases. The case of a patient with T3N2M0 primary squamous cell carcinoma of the rectosigmoid colon, which was initially treated with abdominoperineal resection followed by adjuvant chemotherapy and radiation, is presented. During the follow-up, an elevated squamous cell carcinoma antigen (SCC Ag) level led to restaging computed tomography scans, which confirmed recurrent metastatic disease in the liver. Response to chemotherapy with a decrease in tumor size correlated with a decrease in the serum SCC Ag level. Although SCC Ag has been used as a tumor marker for squamous cell cancers of the lung, head and neck, uterine cervix, and esophagus, this is the first reported case of a squamous cell colon carcinoma presenting with an elevated SCC Ag at the time of recurrence. In addition, this patient showed an objective partial response to combination chemotherapy, with a decrease in the serum level of this tumor marker.

Neuroendocrine carcinoma of the sigmoid colon: report of a case

Neuroendocrine carcinoma of the colon is a rare entity; however, this type of tumor is known for its aggressive progression and poor prognosis. A case of a 56-year-old Japanese male is presented in this report. A huge, child's head-sized tumor was found to have grown extraluminally on the sigmoid colon with multiple liver metastases. The tumor measured 16.5 x 15 x 8.2 cm in size and weighed 1 300 g. The patient died of hepatic failure due to massive liver metastases 6 months after operation. The pathological findings including an electron microscopic analysis were correlated with those of neuroendocrine carcinoma. We reviewed the English literature, and analyzed 94 cases of neuroendocrine carcinoma which had been reported previously. The nomenclature and definition of this disease still remains somewhat unclear, and not a small population of this disease may thus have been misdiagnosed and treated as other less aggressive entities. The necessity to make an accurate differential diagnosis in such cases is thus emphasized.

Adenosquamous carcinoma of the rectum showing endocrine-cell differentiation: report of a case

PURPOSE

Previous records of adenosquamous carcinomas with endocrinologic features rarely have been reported. Although the disease behaves in an extremely aggressive manner, chemotherapy after surgery has never been proposed. We used regional chemotherapy for treatment of unresectable liver metastases.

METHODS

Hartmann colostomy was performed and 5-fluorouracil was infused into the hepatic artery for 15 weeks after the operation.

RESULTS

Multiple liver metastases were present at the initial operation. Three months after the start of the chemotherapy, computed tomography showed that metastatic tumors in the liver had disappeared. The patient survived 18 months after the initial operation.

CONCLUSION

This case report describes the first successful treatment with adjuvant regional chemotherapy of a patient who had an adenosquamous carcinoma with endocrine-cell differentiation in the rectum and liver metastases.

Squamous-cell carcinoma of the colon responsive to combination chemotherapy: report of two cases and review of the literature

PURPOSE

The majority of colorectal neoplasms diagnosed are adenocarcinomas. Other histologies such as squamous, adenosquamous, carcinoid tumors, or lymphoid tumors are occasionally identified. Given the rarity of squamous-cell tumors, it is very difficult to study their natural course and response to therapy. An attempt is made to describe the frequency, anatomic location, and response to therapy with a review of the literature.

METHODS

From the Cancer Registry at the University of Missouri-Columbia Ellis Fischel Cancer Center, tumors of the colon identified above the dentate line were selected for chart review. Data were extracted from cases between the years 1940 and 1996. The key terms used to identify cases were epidermoid, squamous cell, and cancer of the rectum or colon. Using this approach, forty patients were identified and each record was reviewed.

RESULTS

The majority of these cases were anal cancers with proximal extension into the rectum and were excluded. Of 4,561 cases of epithelial colon and rectal cancers identified, only one additional case of squamous-cell cancer could be verified. In this report we describe a patient with a primary squamous-cell carcinoma of the sigmoid colon with metastatic disease to the liver at diagnosis who responded to systemic chemotherapy. We believe this to be the first reported case of this rare tumor type in which the patient's tumor responded to systemic chemotherapy. Two cases with a thorough review of literature are presented.

CONCLUSIONS

Primary squamous-cell carcinoma of the colon is a rare malignancy of unknown cause and pathogenesis. Metastatic tumors to the colon should be ruled out in all cases before therapy. Early detection and surgery remain the main therapeutic options, but as presented in our case, response to chemotherapy in advanced disease is encouraging.

Concordance of genetic alterations in poorly differentiated colorectal neuroendocrine carcinomas and associated adenocarcinomas

BACKGROUND

The histopathologic spectrum of colorectal neuroendocrine tumors ranges from benign to highly malignant. In this spectrum, poorly differentiated neuroendocrine carcinoma (PDNC) is the most aggressive type, characterized by early dissemination and a rapidly fatal course. Since it is unclear whether PDNC originates from neoplastic transformation of preexisting neuroectodermal cells, pluripotent epithelial stem cells, or adenocarcinoma precursor cells, we investigated the histogenesis of this type of cancer by performing genetic analyses on a series of colorectal tumors.

METHODS

Archived histologic sections of colorectal PDNC from nine patients were analyzed; gastrointestinal carcinoid tumor specimens from four patients were used as controls. The specimens were deparaffinized, microdissected, and analyzed genetically. After DNA extraction, polymerase chain reaction amplification was performed to investigate alteration (i.e., loss of heterozygosity [LOH]) of the APC (adenomatous polyposis coli), DCC (deleted in colorectal carcinoma), and p53 (also known as TP53) genes.

RESULTS

LOH of the APC, DCC, or p53 genes was observed in six of eight informative PDNC tumors; no LOH was detected in the carcinoid control specimens. Four of five informative PDNC tumors had associated adenocarcinoma; LOH of the APC and p53 genes in these tumors involved the same allele in both tissue components. Four of the five tumors with associated adenocarcinoma showed LOH of the DCC gene; in three of these four tumors, the PDNC and adenomatous components showed LOH of the same allele.

CONCLUSIONS

PDNC and associated adenocarcinoma appear to be derived from the same cell of origin, which is most likely either a pluripotent epithelial stem cell or an adenocarcinoma precursor cell.

Fine-needle aspiration cytology of metastatic small cell carcinoma of the colon: a report of three cases

Small cell carcinoma of the large intestine is a rare, extremely aggressive malignancy often associated with an overlying adenoma. We report three cases of metastatic small cell carcinoma of the colon diagnosed by fine-needle aspiration (FNA) biopsy. Two of the patients were women (ages 33 and 46 yr old) and one was a man (69 yr old). FNA biopsy established the diagnosis of metastatic small cell carcinoma involving the liver (2 cases) and soft tissue of the scapular region (1 case). In one patient, the FNA diagnosis of hepatic metastases preceded identification of the primary site. Subsequently, the patient was found to have a small cell carcinoma subadjacent to a colonic villous adenoma, illustrating the importance of investigating villous lesions of the colon in patients with metastatic small cell carcinoma of unknown primary origin (especially in non-smokers). All three cases showed the characteristic cytologic features of small cell carcinoma. Ancillary studies performed on aspirated material confirmed the diagnosis of small cell carcinoma in one case. Immunocytochemical studies revealed punctate cytokeratin and diffuse neuron-specific enolase (NSE) positivity of the malignant cells. Ultrastructurally neurosecretory granules were evident. To the best of our knowledge, this is the first FNA cytologic report of metastatic small cell carcinoma of the large intestine. This FNA report also demonstrates when a small cell carcinoma is detected in a metastatic site in a patient lacking a lung primary, a likely primary site could be adjacent or beneath a polypoid lesion of the colon.

Cloacogenic anal carcinoma presenting with humoral hypercalcemia: report of a case

We present herein the case of a 60-year-old man found to have a rare type of cloacogenic anal carcinoma. The disease was advanced and aggressive with local invasion to the prostate as well as distant lymph node metastases to the neck and paraaortic region on presentation. Therefore, a palliative abdominoperineal resection was performed, 10 weeks following which the patient developed humoral hypercalcemia. Despite treatment with hydration, furosemide, steroids, and calcitonin, serum calcium continued to rise and the patient died on the 95th postoperative day. Laboratory findings revealed a decreased parathyroid hormone (PTH) level and marked elevation of parathyroid hormone-related protein (PTHRP). The detection of the PTHRP in the tumor extract and the positive immunohistochemical staining for this in the tumor cells suggested that the humoral hypercalcemia was definitely caused by its associated tumor production. Although hypercalcemia is not an uncommon complication of solid cancers in their late stage, only three other cases of rectal cancer with hypercalcemia have ever been reported. To our knowledge, this is the first documentation of cloacogenic anal carcinoma accompanied by PTHRP-induced severe humoral hypercalcemia.

Small cell neuroendocrine carcinoma of the rectum

Poorly differentiated small cell neuroendocrine (NE) carcinoma of the colon and rectum is a rare primary epithelial malignancy at this location. A case of a highly aggressive NE tumor of small cell type, combined with non-invasive well-differentiated papillary adenocarcinoma in villous adenoma is reported. The patient died rapidly with massive and progressive liver metastasis. The tumor cells were argyrophilic and diffusely immunoreactive for neuronspecific enolase and synaptophysin. Ultrastructural analysis disclosed NE-type cored granules in most of the small tumor cells. NE tumors of the colon and rectum are briefly reviewed.

Carcinomas of the colon with multidirectional differentiation. Report of two cases and review of the literature

Two cases of colonic carcinomas with multidirectional differentiation are presented. Both tumors showed light microscopic and immunohistochemical evidence of areas of adenocarcinomatous, squamous cell carcinomatous, and neuroendocrine differentiation. Only six similar cases have been previously reported. These highly malignant tumors support the recent concept of a multipotential stem cell within the mucosa of the gastrointestinal tract capable of differentiation in several directions.

Carcinoid tumour complicating inflammatory bowel disease. A study of two cases with review of the literature

Two cases of carcinoid tumour complicating inflammatory bowel disease (IBD) are presented. Both tumours were located in the appendiceal tip. The first case occurred in a man with Crohn's disease (CD), and the second one in a woman suffering from ulcerative colitis (UC). Histochemical and immunohistochemical studies were not allowed on case 1 because the tumour was not still present on serial sections of the appendix. On case 2, tumour cells were not reactive with Grimelius and Masson-Fontana stainings, but were strongly stained with anti-keratin and anti-chromogranin monoclonal antibodies (MAb), and faintly expressed neuron specific enolase (NSE), and Leu-7. Both cases occurred in inflammatory or damaged mucosa which exhibited Paneth cell metaplasia and hyperplasia and areas indefinite for dysplasia. Along with these lesions, hyperplasia of enteroendocrine cells was pointed out in the neighbouring appendiceal and colonic mucosa by means of anti-chromogranin MAb. These data suggest that the association of carcinoid tumour with IBD, albeit rare, is not coincidental and is the result of hyperplastic and dysplastic troubles that may involve enteroendocrine cells as well as such other derivatives of digestive stem cells as columnar cells, goblet cells and Paneth cells.

Composite glandular-carcinoid tumour of the terminal ileum

AIMS

To investigate a female patient with a tumour mass of the terminal ileum, to define the nature of the tumour, and to correlate its morphology and behaviour with similar types of tumours of the large intestine and stomach.

METHODS

Tissues obtained at colonoscopy, from hemicolectomy specimens, and from liver and peritoneal biopsy specimens were studied macroscopically, microscopically, histochemically, and immunohistochemically for epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA), neuron specific enolase (NSE), and S100 protein.

RESULTS

Macroscopic examination showed a tumour of the terminal ileum protruding into the caecum. Microscopically the tumour showed two components, one adenoma with moderate dysplasia and the other carcinoid tumour. The adenomatous component stained positively for EMA and CEA and negatively for NSE. The carcinoid component stained positively for NSE and negatively for EMA and CEA. Histochemically the carcinoid area was argyrophil positive and argentaffin negative. Only the carcinoid had metastasised, to the liver, peritoneum, and the lymph nodes, at the time of diagnosis.

CONCLUSION

The morphological, histochemical, and immunohistochemical findings confirm the diagnosis of a composite adenoma-carcinoid tumour of the terminal ileum.

Tripartite differentiation in a carcinoma of the duodenum

BACKGROUND

Carcinomas containing three distinctly different cell lines have been encountered in the colon and rectum, but a tripartite malignancy in the small intestine has not been reported previously.

METHODS

A duodenal carcinoma was studied by light and electron microscopic examination and immunohistochemistry.

RESULTS

The duodenal carcinoma was found to have tripartite glandular, squamous, and neuroendocrine differentiation. Histologically, an adenocarcinoma, which originated in a villous adenoma, was continuous with squamous cell carcinoma and small cell carcinoma components. Tumor cells of the squamous cell carcinoma component had conspicuous intercellular bridges but did not form keratin pearls. Immunohistochemical analysis showed strong expression of carcinoembryonic antigen (CEA) by the adenocarcinomatous component. The squamous cell carcinoma component demonstrated focal weak CEA and neuron specific enolase (NSE) reactivity. Ultrastructurally, tumor cells of this component had frequent desmosomes and free tonofilaments. The small cell carcinoma had clusters of dense core granules in tumor cell cytoplasmic processes, which are indicative of neuroendocrine differentiation. This neuroendocrine component was immunoreactive for somatostatin and NSE.

CONCLUSIONS

This case of tripartite duodenal carcinoma supports the theory of an origin from an intestinal pluripotential stem cell capable of differentiating into multiple cell types.

Characterization of four new cell lines derived from small-cell gastrointestinal carcinoma

Four human small-cell gastrointestinal carcinoma cell lines were established from tumor tissues of patients with esophageal, gastric or rectal cancer, and were studied morphologically and biochemically in comparison with small-cell lung carcinoma (SCLC) cell lines and common gastric cancer cell lines. Cells from all the small-cell gastrointestinal carcinoma lines were as small as classic SCLC cells and had characteristic neurosecretory granules. Cells from only one line grew as tightly packed spherical aggregates of floating cells, and those of the other 3 grew attached to substrate. Although high levels of creatine kinase brain isoenzyme (CK-BB) were detected in all 4 cell lines, 2 of them showed low levels of aromatic L-amino-acid decarboxylase and 3 had low levels of neuron-specific enolase (NSE). None of the lines showed simultaneous elevation of enzymes. C-myc, N-myc, and L-myc were not amplified in any of the cell lines, but c-myc mRNA was expressed in 2 lines. Our findings indicate that all small-cell gastrointestinal carcinoma cells examined belong to the variant type which is used in the classification of SCLC. Furthermore, the ECC18 line, derived from esophageal cancer, seemed to be of true endocrine cell origin, while the 3 other small-cell gastrointestinal carcinoma lines seemed to arise via neoplastic neometaplasia from adenocarcinoma cells to endocrine cells.

Ectopic ACTH syndrome associated with anorectal carcinoma. Report of a case and review of the literature

A 25-year-old black homosexual was noted to be hypertensive, hypokalemic, and to have a rectal mass. Histopathology of the biopsied lesion revealed a mixture of poorly differentiated squamous cell and undifferentiated small cell carcinoma. Abdominopelvic CT showed multiple liver metastases, minimal local tumor extension, and normal adrenal glands. Despite aggressive treatment, he remained hypertensive and hypokalemic. Endocrine work-up revealed: normal 24-hr VMA and catecholamines, normal serum aldosterone and renin levels, elevated urinary free cortisol (3360 micrograms/24 hr), elevated serum cortisol (60 micrograms/dl), and elevated serum ACTH (1697 pg/dl). Liver biopsy confirmed metastatic anorectal carcinoma, and immunohistochemical stains of the rectal biopsy were positive for ACTH and neuron-specific enolase. Although many types of neoplasms have been associated with ectopic ACTH production, small cell carcinoma of the lung is the most common. While there are many reports of colorectal and anorectal neuroendocrine small cell carcinomas, few of these tumors have been associated with clinical ectopic hormone production. This case represents the first report of the ectopic ACTH syndrome associated with anorectal carcinoma.

NCI-H716 cells as a model for endocrine differentiation in colorectal cancer

In colonic neoplasms, endocrine differentiation is encountered not only in carcinoid tumors but also in adenocarcinomas, where endocrine cells may represent a distinct line of differentiation in the tumor. The significance of endocrine differentiation in colorectal cancer is not well established, partly because of the paucity of tumor cell lines which can serve as a model for studying endocrine differentiation. In this report we describe the properties of NCI-H716 cells, a cell line derived from a poorly differentiated adenocarcinoma of the caecum, under various in vitro conditions and as xenografts in athymic mice. Phenotypical properties were immunohistochemically assessed using a panel of differentiation related antibodies, and also by Northern blot analysis and by electron microscopy. Receptors for biogenic amines and peptide hormones were analyzed by ligand binding assay. These studies show that: 1. NCI-H716 cells can be undifferentiated, or show endocrine, mucin-producing or "amphicrine" properties. 2. Endocrine differentiation of NCI-H716 cells preferentially occurs in xenografts in athymic mice, which suggests that mesenchymal elements induce endocrine differentiation. 3. NCI-H716 cells express large amounts of high affinity receptors for gastrin, serotonin and somatostatin and these substances can regulate growth. Thus, NCI-H716 cells form a suitable model for the study of endocrine differentiation in intestinal epithelium and of auto- or paracrine growth regulation in intestinal neoplasia.

Small cell undifferentiated ('neuroendocrine') carcinoma of the colon

Three patients are described who presented with a large colonic adenoma in which a solid, undifferentiated carcinomatous component was found on microscopic examination. Despite small size (1.0 and 1.5 cm) and submucosal location in two cases, the tumours had metastasized to regional lymph nodes and the liver and death ensued at 4, 11 and 18 weeks after surgery. Immunocytochemistry was positive for carcino-embryonic antigen, low molecular weight cytokeratins and neuron specific enolase in all three cases and scanty dense core granules of neurosecretory type were found in one of two examined by electron microscopy. These 'neuroendocrine' carcinomas are compared with 'pure' adenomas and 'ordinary' poorly differentiated adenocarcinomas of the colon from which they differ, mainly by lack of glandular differentiation and mucus secretion, although two adenocarcinomas also showed patchy reactivity for neuron specific enolase. The term 'neuroendocrine' may be disputed but is now well established to describe a tumour that runs a uniquely aggressive course and for which radical surgery alone cannot provide a cure.

Primary composite squamous cell carcinoma and large cell neuroendocrine carcinoma of the hypopharynx

Neuroendocrine carcinomas are rare neoplasms of the larynx and hypopharynx. Tumours composed of both neuroendocrine and squamous cell elements are very rare. We report a case of a primary hypopharyngeal carcinoma composed of both squamous cell and large cell neuroendocrine carcinoma and discuss the treatment of this patient and management of neuroendocrine carcinomas of the larynx and hypopharynx.

Adenosquamous carcinoma of the colon--an immunocytochemical and ultrastructural study. Report of two cases and review of the literature

This paper presents two cases of adenosquamous carcinoma of the colon and brings to 39 the total number documented in medical literature. The concurrent glandular and squamous differentiation of the tumor cells was demonstrated by immunocytochemistry and electron microscopy. Evaluation of the biologic characteristics of all the reported cases suggests that malignant squamous elements in colonic carcinomas behave more aggressively than their glandular counterparts. In contradistinction from the pure squamous-cell carcinoma of the colon, adenosquamous carcinoma does not show the same predilection for the right colon.

Adenocarcinoid of the vermiform appendix. A clinicopathologic study of 20 cases

Adenocarcinoid of the appendix is a tumor that shares the histologic features of both carcinoids and adenocarcinomas. The metastatic ability of the tumor is uncertain. Twenty consecutive cases of adenocarcinoids were compared with 88 cases of conventional appendiceal carcinoids. Metastatic tumor spread was found in six of 20 cases of adenocarcinoids, but in none of the conventional carcinoids. Metastasizing tumors were characterized by a moderate to severe nuclear atypia and a high mitotic count. These features were present in only two of the nonmetastasizing tumors, one of which was treated by hemicolectomy. Adenocarcinoids showing moderate or severe nuclear atypia, a mitotic count of two or more mitoses/10 high power fields, or spread beyond the appendix should be treated by hemicolectomy. If these features are not present, simple appendectomy is adequate.

Adenosquamous carcinoma of the colon presenting with hypercalcemia

A rare adenosquamous carcinoma of the colon occurred in a 41-year-old patient. Its presentation with hypercalcemia, in the absence of osseous metastases, has not been described previously. The hypercalcemia in this case was due to the elaboration of a parathyroid hormone-like substance by the tumor. The general characteristics of primary adenosquamous and squamous cell carcinomas of the colon are presented. These tumors present with advanced disease, in younger patients, and follow a highly aggressive course, as compared with adenocarcinomas of the colon. The cause of the malignancies, in the light of current theories regarding their genesis, is discussed.