# Cancer Diaspora of Undifferentiated Cancer

## TL;DR

An 83-year-old cancer survivor died from aggressive undifferentiated cancer that spread rapidly, despite previous diagnoses of cured cancers.

## Contribution

Highlights the limitations of imaging tools in diagnosing aggressive undifferentiated cancer and the need for clinicians to reconsider old assumptions.

## Key findings

- Undifferentiated cancer infiltrated the entire body and was misdiagnosed by PET/CT and MRI.
- The origin of the cancer could not be determined despite thorough pathological evaluation.
- The case illustrates the rapid progression of undifferentiated cancer despite prior cancer remissions.

## Abstract

Undifferentiated cancer is a rapidly progressing cancer with poor prognosis. Sometimes, it is diagnosed at an advanced stage, and its origin is difficult to detect. A very unusual cancer was revealed by autopsy. The patient was an 83-year-old survivor of colon cancer, melanoma, and laryngeal cancer. He had been under watchful course observation after survival from laryngeal cancer but suddenly died due to aspiration pneumonia. The autopsy revealed undifferentiated cancer infiltrated the entire body, which was misdiagnosed with positron emission tomography (PET)/CT scan and MRI. The origin of this cancer was a mystery even with vigorous pathological evaluation. The patient was told that his previous cancers were all healed; however, undifferentiated cancer progressed rapidly to the entire body, just like “cancer diaspora”. This report highlights the limit of diagnostic imaging tools for aggressive cancer, sounding the alarm for clinicians to look beyond old presumptions.