Collision tumour of the oesophagus: a challenge for histological diagnosis

A Pancreatic Collision Tumor Comprising Mantle Cell Lymphoma and Adenocarcinoma: A Case Report and Literature Review

A collision tumor is a rare clinical condition where two different tumors occur synchronically within a lesion. Pancreatic collision tumors with mantle cell lymphoma (MCL) are extremely rare and have only been reported in one case to date. We herein report an elderly patient with MCL and adenocarcinoma of the pancreas with Ann Arbor stage IV and Union for International Cancer Control stage IIB, respectively. The patient received palliative therapy and died 23 months after the diagnosis. Further research and case studies are required to investigate whether or not MCL-derived cyclin D1 overexpression affects the occurrence/growth of adenocarcinomas.

A Rare Case of Collision Tumours of the Ovary: An Ovarian Serous Cystadenoma Coexisting with Fibrothecoma

The incidence of epithelial tumours of the ovary ranges from 9-17 per 100,000 and is the highest in high-income countries, with the exception of the Japan. The coexistence of neoplastic Müllerian epithelial and sex cord-stromal elements within a single tumour is extremely rare. We describe the case of a 74-year-old woman with a voluminous left adnexal formation. Pre-operative assessment with ultrasound evaluation made a suspicious diagnosis of benignity of the lesion. Bilateral salpingo-ovariectomy was performed. Intraoperative frozen section analysis results in the diagnosis of fibrothecoma in the context of serous cystadenoma. The diagnosis is confirmed by histological examination. Some authors suggest labelling this phenomenon as collision tumours.

Ovarian collision tumors: imaging findings, pathological characteristics, diagnosis, and differential diagnosis

Collision tumors are uncommon neoplasms in which elements of differing histologic origins coexist in a single mass. Ovarian collision tumors are a rare subtype of such lesions. The identification of collision tumors by radiologic examinations is essential to ensure that comprehensive biopsies are performed to guide appropriate treatments. According to the clinical and imaging findings of 12 patients and reviews of previous studies, ovarian collision tumors are mixtures of different combinations of epithelial tumors, germ cell tumors, and sex-cord-stromal tumors. The smaller tumors are usually located inside ("nested tumor") or on the wall ("back to back") of the larger tumors. Each type of ovarian collision tumors presents specific CT/MRI features in accordance with their histologic origins and collision patterns. Knowledge of the imaging features of ovarian collision tumors is crucial to aid preoperative diagnostic accuracy.

A collision tumor of esophagus

The collision tumor is defined by Meyer as that arisen from the accidental meeting and eventual intermingling of two independent neoplasms, which is quite rare. Most of them occur in the junction of different epithelial types of tissue such as oral cavity, esophagogastric junction, anorectaljunction and cervix, while collision tumors occurring in the liver, gallbladder, pancreatic, urinary bladder also have been reported. Here we present a case of 55-year-old Chinese man diagnosed as a collision tumor composed of leiomyosarcoma and squamous cell carcinoma (SqCC) in the lower third part of esophagus with 6 years survival after surgery and radiotherapy.

A rare collision tumor of squamous carcinoma and small cell carcinoma in esophagus involved with separate lymph nodes: a case report

We report a case of an esophageal collision tumor composed of squamous cell carcinoma and small cell carcinoma (SmCC). A 66-year-old man complained of chest pain after oral intake for nearly one month. The patient received two cycles of neoadjuvant platinum-based combination chemotherapy and enhanced computed tomography showed a partial response of the tumor. He then underwent a thoracolaparoscopic esophagectomy with extensive mediastinal lymphadenectomy. Two cycles of chemotherapy and prophylactic irradiation of the lymphatic drainage region were sequentially achieved after surgery. The patient has survived for more than 18 months with no evidence of recurrent disease since surgical resection.

Collision tumor: serous cystadenocarcinoma and dermoid cyst in the same ovary

INTRODUCTION

Collision tumor means the coexistence of two adjacent, but histologically distinct tumors without histologic admixture in the same tissue or organ. Collision tumors involving ovaries are extremely rare.

CASE

We present a case of 45-year-old parous woman with a left dermoid cyst, with unusual imaging findings, massive ascites and peritoneal carcinomatosis. The patient underwent cytoreductive surgery. The histopathology revealed a collision tumor consisting of an invasive serous cystadenocarcinoma and a dermoid cyst.

Imaging findings of complications and unusual manifestations of ovarian teratomas

Ovarian teratomas can be associated with various complications and demonstrate a wide spectrum of clinical and imaging features. The complications include torsion (16% of ovarian teratomas), rupture (1%-4%), malignant transformation (1%-2%), infection (1%), and autoimmune hemolytic anemia (<1%). These complications require different therapeutic strategies; therefore, timely and accurate diagnosis of these complications is important for optimal patient treatment. In cases of complicated ovarian teratomas, the clinical manifestations provide only limited information and often overlap with those of other diseases. Furthermore, ovarian teratomas may have unusual clinical and imaging manifestations, thereby leading to misdiagnosis. These unusual manifestations include immature teratomas, monodermal teratomas (struma ovarii), combination tumors and collision tumors containing teratomas, and mature cystic teratomas without demonstrable fat or with pure fatty components. To provide adequate treatment and prevent misdiagnosis, it is necessary to be familiar with the imaging findings of both the complications and the unusual manifestations of ovarian teratomas.

Collision tumors of the ovary associated with teratoma: clues to the correct preoperative diagnosis

PURPOSE

Collision tumors represent a coexistence of two adjacent but histologically distinct tumors without histologic admixture in an organ. The purpose of this study was to describe the imaging findings of collision tumors of the ovary associated with teratoma and to look for clues that might lead to the correct preoperative diagnosis.

METHOD

Seven pathologically proven cases of collision tumor of the ovary associated with teratoma were retrospectively reviewed. Ovarian teratomas were coexistent with mucinous cystadenoma (n = 4), borderline mucinous tumor (n = 1), mucinous cystadenocarcinoma (n = 1), and dysgerminoma (n = 1). US (n = 5), CT (n = 3), and/or MRI (n = 4) findings were evaluated.

RESULTS

In addition to the typical findings of teratoma, the mass contained a multiloculated cystic portion filled with nonfatty fluid, suggesting the coexistent epithelial tumor in five cases. In one case, the mass contained a large solid component, suggesting the possibility of collision tumor. In the remaining one case, coexistent small mucinous cystadenoma could not be identified.

CONCLUSION

Preoperative imaging for ovarian teratoma revealed a collision tumor in six of seven cases. The possibility of a collision tumor should be considered when an ovarian teratoma has imaging findings that cannot be explained solely by an ovarian teratoma.