Adenocarcinoma of the colon with syncytiotrophoblastic differentiation: differential diagnosis and implications

Primary colon adenocarcinoma with choriocarcinoma differentiation: a case report and review of the literature

Background

Choriocarcinoma is an aggressive malignancy of trophoblastic tissue, typically of gestational etiology. Sporadic, nongestational cases are rarely found outside of the gonads. There are only 31 cases of primary choriocarcinoma of the colon reported in the literature. As a consequence of their rarity and aggressive nature, timely diagnosis and effective treatment have proved challenging, and prognosis is very poor. For that reason, we present a rare case with prolonged survival in the youngest reported patient .

Case presentation

A 26-year-old Caucasian woman presented with abdominal cramping and rectal and vaginal bleeding. Elevated serum human chorionic gonadotropin and an 8-cm right-sided mass seen on ultrasound suggested ectopic pregnancy. The patient was treated with methotrexate; however, her symptoms persisted, and her human chorionic gonadotropin levels continued to rise. Further workup showed a large mass of the sigmoid colon with multiple hepatic lesions suggestive of metastases. Preliminary pathology showed adenocarcinoma. Despite surgical resection and initiation of FOLFOX chemotherapy (folinic acid, fluorouracil, oxaliplatin), the patient had significant clinical deterioration, and her human chorionic gonadotropin increased exponentially. Further pathological review showed two distinct phenotypes: adenocarcinoma merging with choriocarcinoma. The result of evaluation of the metastatic lesions was also positive for choriocarcinoma. Treatment was promptly changed to a choriocarcinoma-targeting chemotherapy regimen of EMA/CO (etoposide, methotrexate, actinomycin D, cyclophosphamide, vincristine), resulting in rapid and dramatic response. The patient had mild progression after 1 year and was switched back to FOLFOX with bevacizumab. After five cycles, scans showed further progression, and the patient was started on third-line therapy with FOLFIRI (folinic acid, fluorouracil, irinotecan) and bevacizumab. Eighteen months after her diagnosis, the patient was alive and maintaining an overall response.

Conclusions

Our patient achieved a marked response and prolonged survival. Although a comprehensive review of the literature showed that survival with these tumors has improved over the past 10 years, prognosis remains poor. Currently, there is no established algorithm for the management of these rare tumors, but both the literature and our patient’s case indicate that a choriocarcinoma-targeted regimen is critical for survival. Further evaluation of these rare tumors is warranted in order to identify pathological patterns that may help in the diagnosis, management, and survival of these malignancies.

Unusual abscess masquerading as poorly differentiated adenocarcinoma of the colon showing characteristics of choriocarcinoma

Extragonadal non-gestational choriocarcinoma (ENC) is an uncommon malignant tumor occasionally found in the gastrointestinal tract. ENC is characterized by a biphasic tumor growth with distinct areas of adenocarcinoma and choriocarcinoma differentiation. Primary choriocarcinoma of the colon is extremely rare, with only 21 cases reported in the literature. Most of the perforation of colorectal cancers occurs in the abdominal cavity, while abdominal wall abscess is rare; the psoas abscess associated with colon carcinoma is even less observed. Herein, we report the case of a 61-year-old female with poorly differentiated adenocarcinoma of the ascending colon and sigmoid, with choriocarcinomatous differentiation, masquerading a psoas abscess formation. Unfortunately, despite the aggressive therapy, the patient’s disease rapidly progressed, and she died within 2 months after the diagnosis. The typical morphological pattern, immunohistochemistry, and its correlation with serum β-human chorionic gonadotropin enabled a correct diagnosis.

A rare case of primary rectal choriocarcinoma and review of the literature

INTRODUCTION

Primary choriocarcinoma of the colon is an extremely rare neoplasm which has a poor prognosis. Only 18 cases have been previously reported in English medical literature. Here we present a case of primary rectal choriocarcinoma with a good response to chemotherapy and review the literature on this uncommon tumor.

CASE REPORT

A 36-year-old woman presented with abdominal pain and vaginal bleeding. Abdominal magnetic resonance imaging revealed 6.9 × 5.3 × 6.4 cm hypervascular mass posterior to uterus very close to rectum. Beta-human chorionic gonadotropin (β-hCG) level was markedly elevated. Low anterior resection of the rectum with lymph node dissection and total abdominal hysterectomy with bilateral salpingo-oophorectomy were performed. Pathologic diagnosis was reported as colonic choriocarcinoma with a focal component of adenocarcinoma. Post-operative magnetic resonance imaging detected multiple metastatic lesions throughout the liver. The patient was treated with systemic chemotherapy using bleomycin, etoposide and cisplatin (BEP protocol). After three cycles, β-hCG level decreased to normal and magnetic resonance imaging showed regression of liver metastasis. However, the patient died of respiratory failure due to bleomycin toxicity and pneumonia accompanied by rapid disease progression.

DISCUSSION

This is an extremely rare case of primary rectal choriocarcinoma. Due to poor prognosis of the disease, it seems very important to start prompt treatment to improve patient's survival.

Primary Adenocarcinoma with Focal Choriocarcinomatous Differentiation in the Sigmoid Colon

Primary colorectal choriocarcinoma is a rare neoplasm. Only 19 cases have been reported worldwide, most of which involved adenocarcinomas. The prognosis is usually poor, and the standard therapy for this tumor has not been established. A 61-year-old woman presented with constipation and lower abdominal discomfort. She was diagnosed with primary adenocarcinoma with focal choriocarcinomatous differentiation in the sigmoid colon and liver metastasis. Because the serum beta-human chorionic gonadotropin level was not significantly elevated, and because only focal choriocarcinomatous differentiation was diagnosed, we selected the chemotherapy regimen that is used for the treatment of metastatic colorectal adenocarcinoma. The patient survived for 13 months after the initial diagnosis. This is the first case in Korea to assess the suppressive effects of the standard chemotherapy for colorectal adenocarcinoma against coexisting colorectal choriocarcinoma and adenocarcinoma.

Primary Choriocarcinoma of the Rectum in a Man Case Report and Literature Review

A case of pure extragonadal choriocarcinoma in the rectum of an 84-year-old man is described. The patient complained of rectal bleeding and lower abdominal pain. The trophoblastic origin of the tumor was documented by immunoperoxidase staining for human chorionic gonadotropin. The DNA histogram showed a diploid pattern. The patient died 106 days after diagnosis. Only eight cases of choriocarcinoma of the large intestine have been reported, three of which were located in the rectum. The age of patients affected range widely, from 28 to 84 years with a mean of 54 years: 79 for males and 46 for females. Women are affected three times as often as men. The pathologic study showed adenocarcinoma with germ cell elements in seven cases: six choriocarcinoma and one mixed (choriocarcinoma and endodermal sinus tumor). Germ cell differentiation may be difficult to identify in small biopsy samples, which may not be representative of the tumor as a whole. The prognosis of patients with choriocarcinoma of the large bowel is very poor; survival is less than 5 months. Although choriocarcinoma in the rectum is very rare, it should be included in the differential diagnosis of rectal neoplasms.

Primary choriocarcinoma of the colon: a case report and review of the literature

Choriocarcinoma usually arises in the uterus and gonads. Primary choriocarcinoma (PCC) in an extragenital organ is rare. When it occurs in the gastrointestinal tract, the stomach is the most common site. Only 12 cases of PCC of the colon have been reported in the world literature. Most cases were associated with adenocarcinoma. We report the case of a 36-year-old man with PCC of the colon and review the clinical characteristics of previously documented cases.

Rectal adenocarcinoma with germ-cell differentiation: report of a case

A 26-year-old male presented with a colorectal adenocarcinoma with germ-cell differentiation and an isolated elevation of serum alpha-fetoprotein. He was treated with platinum/etoposide/bleomycin chemotherapy with a decrease in serum alpha-fetoprotein and in the size of the primary tumor. An ongoing tumor-marker response occurred when the patient was switched to concurrent 5-fluorouracil chemotherapy and radiation therapy. The patient underwent a palliative diversion of his rectal cancer 10 months after diagnosis, developed liver metastasis at 12 months, and died 20 months after diagnosis.

Choriocarcinomatous metaplasia of a metachronous adenocarcinoma of the colon

A second primary colonic adenocarcinoma developed in a 68-year-old man following resection of a rectal adenocarcinoma. Choriocarcinomatous change was found in the metachronous lesion with liver metastases and elevated beta-human choriogonadotrophin (HCG) serum titres.

Colonic adenocarcinoma metastasizing as a germ cell neoplasm: a case report and review of the literature

Mixed tumors of the gastrointestinal tract, including both adenocarcinoma and germ cell neoplasm, have been reported infrequently. In the colon, only 9 cases, to our knowledge, have been described in the English-language literature. This is the case of a 29-year-old man with an unsuspected mixed colonic neoplasm that metastasized as the germ cell component.

Rectal adenocarcinoma with germ cell elements treated with chemotherapy

A patient with adenocarcinoma of the rectum containing germ cell elements in the form of endodermal sinus tumor and choriocarcinoma is described, believed to be the first such tumor reported in the literature. The serum levels of alpha-fetoprotein and human chorionic gonadotropin were markedly elevated. The source of the markers was localized to the neoplastic tissue by the immunoperoxidase technique. The patient developed extensive hepatic metastases thought to be due to choriocarcinoma for which she received chemotherapy. One wk after commencing treatment a massive fatal hepatic hemorrhage occurred.

Combined choriocarcinoma and adenocarcinoma of the lung

Combined choriocarcinoma and adenocarcinoma in the lung of a 71-year-old Japanese male is reported. In the upper lobe of the right lung (S1 + 2), a choriocarcinoma coexisted with an adenocarcinoma, but distinct metastatic lesions were noticed separately in the lungs, kidney, bone marrow and lymph nodes. Although immunohistochemical examination revealed intensely positive reactivity with anti-human chorionic gonadotropin (HCG) in trophoblastic cells, weak immunoreactivities were also observed in a few cells with anti-human placental lactogen (HPL), anti-pregnancy-specific beta glycoprotein (SPI), anti-epithelial membrane antigen (EMA), anti-carcinoembryonic antigen (CEA), anti-cytokeratin (keratin) and KM-93 (lung adenocarcinoma-associated antibody). In the adenocarcinoma, the tumor cells were positively stained for CEA, EMA, keratin and KM-93, but there were no positive reactivities for HCG, HPL and SPI. These findings suggest that primary choriocarcinoma of the lung may arise through dedifferentiation of adenocarcinoma.

Human chorionic gonadotropin in gastric carcinoma. An immunohistochemical study suggesting independent regulation of subunits

To investigate the production of human chorionic gonadotropin (hCG) in gastric carcinoma, 124 gastric carcinomas and a choriocarcinoma with adenocarcinoma were examined immunohistochemically, using anti-hCG alpha and beta antibodies. In choriocarcinoma, many trophoblastic cells were synchronously positive for both subunits. In contrast, the distribution of hCG-subunits in gastric carcinoma was unbalanced with hCG alpha in 39 and hCG beta in 63 cases. 26 cases contained alpha and beta positive cells, whereas synchronous cells were extremely rare in four cases. Incidences of hCG-subunit-positivities were not different between early and advanced carcinomas. HCG alpha-positive cells appeared endocrine-like in papillotubular carcinomas and some positive cells were argyrophilic in serial sections in 23 of 39 cases. HCG beta-positive cells were much more frequent in deranged glands, especially of microtubular-mucocellular carcinomas and most were not argyrophilic. In surrounding non-neoplastic mucosa, hCG alpha-positive cells were more numerous with endocrine-like configurations, but hCG beta-positive cells were rarely present in deranged glands. Although subunit-profile of hCG in gastric carcinomas was different from that of normal, the difference may be quantitative: hCG-subunits may be expressed through an independent mechanism but commonly in gastric mucosa and carcinoma. These results are also discussed in relation to trophoblastic tumours arising in non-trophoblastic tissues.

Human chorionic gonadotrophin expression in colorectal adenocarcinoma

The presence of human chorionic gonadotrophin (HCG) in colorectal adenocarcinoma was studied histologically in 45 tumors using immunoperoxidase technique. Ten neoplasms (22.2 percent) contained HCG-positive tumor cells. These cells were present mostly at the periphery of the tumors. Many formed parts of glands, while some were arranged in syncytial clumps or columns, or singularly. Thus, these tumor cells resembled trophoblastic tissue not only in being HCG-positive but also in their peripheral distribution and occasionally in morphologic appearance. HCG-positive tumors were seen more commonly in the rectosigmoid region (90 percent) and were more aggressive than HCG-negative tumors. In this study, lymph node or liver metastases were present in 70 percent of HCG-positive tumors compared with 29 percent of negative tumors--a difference which is statistically significant.

Gastric choriocarcinoma; an immunohistochemical study

A case is reported of primary gastric choriocarcinoma occurring in a 73-year-old man, associated with a high serum level of beta hCG. Both primary and lymph node metastases contained exclusively cyto and syncytiotrophoblastic elements. Immunohistochemical localization of chorionic gonadotropin (hCG), placental lactogen (hPL) and pregnancy-specific glycoprotein (SP 1) is described in relation to cytotrophoblastic differentiation. An intramucosal focus of adenocarcinoma supports the hypothesis of the origin of choriocarcinoma from usual gastric cancer.