Synchronous collision malignant melanoma and adenocarcinoma of the rectum

Clinicopathological characteristics of co-existing or mixed colorectal cancer and neuroendocrine tumor: Report of five cases

Coexisting or mixed type of colorectal tumors has been rarely reported. This study was designed to investigate clinicopathological characteristics of co-existing or mixed colorectal adenocarcinoma and highly differentiated neuroendocrine tumor (NET-G1). To do that, clinicopathological characteristics of five cases of co-existing or mixed colorectal adenocarcinoma and NET-G1 admitted to our institution between 2017 and 2021 were retrospectively analyzed and literature review was conducted. Four patients were male and one female, aged 62-75 years old. Among them, four cases were diagnosed with rectal cancer and one case of colon cancer. Gross examination found that one patient was diagnosed with multiple colon polyps including three malignant polyps, and the remaining four cases of ulcerous masses. The tumors infiltrated into the muscle layer in two cases, and three cases with tumors infiltrating into surrounding adipose tissues. Microscopic examination revealed one patient developed poorly differentiated adenocarcinoma and four cases of moderately differentiated adenocarcinoma. Four patients had adenocarcinoma and NET-G1 in colon, and one case of adenocarcinoma in colon and NET-G1 in appendix. To conclude, co-existing or mixed colorectal tumors are extremely rare in clinical settings. Clinicopathological characteristics of five cases of co-existing or mixed adenocarcinoma and NET-G1 are diverse and adenocarcinoma is more aggressive in most affected patients.

Mixed epithelial endocrine neoplasms of the colon and rectum – An evolution over time: A systematic review

BACKGROUND

Mixed tumors of the colon and rectum, composed of a combination of epithelial and endocrine elements of benign and malignant potential are rare neoplasms. These can occur anywhere in the gastrointestinal tract and are often diagnosed incidentally. Though they have been a well-documented entity in the pancreas, where the exocrine-endocrine mixed tumors have been known for a while, recognition and accurate diagnosis of these tumors in the colon and rectum, to date, remains a challenge. This is further compounded by the different terminologies that have been attributed to these lesions over the years adding to increased confusion and misclassification. Therefore, dedicated literature reviews of these lesions in the colon and rectum are inconsistent and are predominantly limited to case reports and case series of limited case numbers. Though, most of these tumors are high grade and of advanced stage, intermediate and low grade lesions of these mixed tumors are also increasingly been reported. There are no established independent consensus based guidelines for the therapeutic patient management of these unique lesions.

AIM

To provide a comprehensive targeted literature review of these complex mixed tumors in the colon and rectum that chronicles the evolution over time with summarization of historical perspectives of terminology and to further our understanding regarding their pathogenesis including genomic landscape, clinicoradiological features, pathology, treatment, prognosis, the current status of the management of the primary lesions, their recurrences and metastases.

METHODS

A comprehensive review of the published English literature was conducted using the search engines PubMed, MEDLINE and GOOGLE scholar. The following search terms [“mixed tumors colon” OR mixed endocrine/neuroendocrine tumor/neoplasm/lesion colon OR adenocarcinoma and endocrine/neuroendocrine tumor colon OR mixed adenocarcinoma and endocrine/neuroendocrine carcinoma colon OR Amphicrine tumors OR Collision tumors] were used. Eligibility criteria were defined and all potential relevant items, including full articles and/or abstracts were independently reviewed, assessed and agreed upon items were selected for in-depth analysis.

RESULTS

In total 237 full articles/abstracts documents were considered for eligibility of which 45 articles were illegible resulting in a total of 192 articles that were assessed for eligibility of which 139 have been selected for reference in this current review. This seminal manuscript is a one stop article that provides a detailed outlook on the evolution over time with summarization of historical perspectives, nomenclature, clinicoradiological features, pathology, treatment, prognosis and the current status of the management of both the primary lesions, their recurrences and metastases. Gaps in knowledge have also been identified and discussed. An important outcome of this manuscript is the justified proposal for a new, simple, clinically relevant, non-ambiguous terminology for these lesions to be referred to as mixed epithelial endocrine neoplasms (MEENs).

CONCLUSION

MEEN of the colon and rectum are poorly understood rare entities that encompass an extensive range of heterogeneous tumors with a wide variety of combinations leading to tumors of high, intermediate or low grade malignant potential. This proposed new revised terminology of MEEN will solve the biggest hurdle of confusion and misclassification that plagues these rare unique colorectal neoplasms thus facilitating the future design of multi institutional prospective randomized controlled clinical trials to develop and evaluate newer therapeutic strategies that are recommended for continued improved understanding and personal optimization of clinical management of these unique colorectal neoplasms.

Primary anorectal melanoma-a rare entity: case report

Anorectal melanoma is a rare disorder. There have only been a few cases reported and there is no consensus of treatment. We report a case of 50-year-old Caucasian man presenting intermittent prolapse of an anorectal mass during 6 months with occasional bleeding. Biopsies came up with the diagnosis of malignant melanoma. No distant metastases were found. He underwent an abdominoperineal resection due to internal sphincter invasion. A second tumour was diagnosed in final histologic examination: a dysplastic rectal polyp invaded by the melanoma (collision tumour). At 12 months of follow up he presented loco-regional recurrence (a single pelvic lymph node) and hepatic metastases. He was included in a study protocol comparing new medical treatments (nivolumab versus ipilimumab or both).

Objective response to mTOR inhibition in a metastatic collision tumor of the liver composed of melanoma and adenocarcinoma with TSC1 loss: a case report

Background

Collision tumors are uncommon but well described clinical entities composed of distinct tumor histologies occurring within the same anatomic site. Optimal management of patients with collision tumors remains highly variable and depends on clinical characteristics such as the involved tumor types, predominant histology, as well as the extent of disease. Comprehensive genomic profiling is a means of identifying genomic alterations to suggest benefit from targeted therapy.

Case presentation

A 78-year-old woman presented to medical oncology with liver metastases occurring within the background of a 1-year history of uveal melanoma. Biopsy of the liver metastases revealed presence of adenocarcinoma along with nests of malignant melanoma consistent with a collision tumor. The disease was refractory to several lines of conventional cytotoxic chemotherapy, and the patient later developed pulmonary metastases while on chemotherapy. The patient’s tumor tissue was assayed by comprehensive genomic profiling which revealed presence of a TSC1 partial loss. The patient was subsequently initiated on temsirolimus 15 mg intravenously weekly for 4 months. Restaging imaging demonstrated a partial response to therapy by RECIST 1.1 criteria and clinical benefit for 6 months until the patient passed away secondary to unrelated causes.

Conclusions

We report the first case of a collision tumor composed of adenocarcinoma and melanoma with a TSC1 mutation that objectively and durably responded to mTOR inhibition.

Synchronous Primary Anorectal Melanoma, Sigmoid Multiple Early Cancers and Descending Adenocarcinoma: A Case Report

Multiple colorectal cancers are extremely rare, few cases can be searched in the literature. Our group only found 6 cases published. We report a case where 3 diseases coexisted summarize the currently available literature. A 75-year-old man presented with changes in his bowel habits and hematochezia. After a colonoscopy with biopsies in a community hospital, he was diagnosed with a descending adenocarcinoma patient. To get further treatment, he came to our hospital. Colonoscopy revealed ulcerative lesions in the descending colon, 2 polypoid lesions in the sigmoid colon, and a protruded lesions in the anorectal. The ulcerative lesions were already diagnosed as adenocarcinoma at the descending colon. So biopsies were taken in the anorectal region, which revealed poorly differentiated melanoma of the anorectal. Computed tomography did not find distant metastases and regional lymphadenopathy. A laparoscopic resection was undertaken to relieve his symptoms and improve the quality of life. The mass showed descending adenocarcinoma, sigmoid multiple early cancers, and poorly differentiated melanoma of the anorectal region. What we can learn is that endoscopy doctors should always be aware of the possibilities of multiple primary cancers for this is important to the treatment and prognosis of patients, standard colonoscopy examination is necessary and returning a enteroscope from cecum should be more than 8 minutes.

Synchronous primary anorectal melanoma and sigmoid adenocarcinoma: a case report

Synchronous primary anorectal melanoma and colorectal adenocarcinoma is extremely rare, with only 5 cases reported in the literature. Here, a case is reported and the currently available literature is summarized. A 72-year-old white male presented with changes in his bowel habits and unintentional weight loss. Colonoscopy revealed a polypoid mass in the distal rectum extending to the anal verge anteriorly and a circumferential polypoid mass in the distal sigmoid colon. Biopsies were taken, which revealed poorly differentiated melanoma of the anorectal mass and moderately differentiated adenocarcinoma of the sigmoid mass with nodal involvement. Computed tomography of the abdomen showed liver metastasis. An extended abdominoperineal resection was undertaken for palliation, relief of symptoms, and definitive histology to guide further management. Consequently, a resection of the hepatic metastasis was attempted; however, macroscopic deposits were discovered on 7 of 8 liver segments perioperatively. He was subsequently referred to medical oncology for palliative chemotherapy. Synchronous primary anorectal melanoma and colorectal adenocarcinoma is rare, this being the sixth report found in the literature. In summary of the available cases, all synchronous cancers were located in the rectosigmoid and had very similar presentations. Most presented relatively late and were generally treated with abdominoperineal resection, which appears to be the best treatment option. Overall, prognosis appears to be dismal. General and colorectal surgeons should always be aware of the possibilities of simultaneous primary cancers because this can affect treatment modalities and prognosis for the patient.