Primary and metastatic malignant melanomas of the digestive system

Purpose:

Primary and metastatic digestive system malignant melanomas are extremely rare. In our study, we aimed to compare lymph node metastasis with clinical and pathological parameters in gallbladder, stomach, small intestine and anorectal region malignant melanomas.

Materials and methods:

This retrospective study included 20 cases diagnosed with malignant melanoma in the gastrointestinal tract organs between January 2010 and January 2020 at XXXXXXXXXXXX. In our study, we wanted to evaluate the relationship between regional lymph node metastasis and age, gender, tumor localization, tumor size, extraintestinal melanoma history, melanin pigment, neutrophil-lymphocyte ratio and post-diagnosis life span in primary and metastatic malignant melanoma cases. We also reviewed the origin and literature of the cells from which melanoma originates in the digestive system.

Results:

There was a statistical relationship between tumor diameter and regional lymph node metastasis (p =0.000). As the tumor diameter increased, the lymph node metastasis rate increased. There was a relationship between survival and gender, tumor localization, distant metastasis, primary and metastatic digestive system melanoma (all p <0.05). Most of the men and those who did not metastasize away from the digestive system were alive. All patients with melanoma metastases to the digestive system and all patients with gallbladder and small intestine localization were alive. Our 70 year old patient with gallbladder primary malignant melanoma was the oldest patient we could identify in the literature.

Conclusions:

Regardless of cutaneous or origin, all melanomas originate from melanocytes, cells derived from embryological nerve crest. Malignant melanoma can be primary in every region, more frequently in the anorectal region in the gastrointestinal tract. The most common metastasis is to the small intestine. Accurate diagnosis is vital in places where it is rarely seen, such as the digestive system. Recently, in metastatic melanoma, immuno-oncological agents are used in adjuvant therapy to help prevent metastatic spread of the disease. Thanks to these treatments, it is reported that more than half of patients with melanoma who have the risk of metastasis after surgical resection provide recurrence-free survival. Although it is very rare, it should be kept in mind that there may be primary or metastatic malignant melanoma in the evaluation of digestive system biopsies.