Undifferentiated Pancreatic Carcinomas, Clinical Features and Therapeutic Options: What We Know

SIMPLE SUMMARY: Undifferentiated pancreatic carcinomas are a very rare form of malignant pancreatic cancer that are difficult to diagnose and very aggressive. They are a kind of anaplastic pancreatic cancer that accounts for less than 10% of all pancreatic cancers. The WHO classifies undifferentiated pancreatic cancers into osteoclast-like giant cell type, sarcomatoid type and rhabdoid type. Patients may have KRAS, TP53 and SMAD4 alterations. In some cases, INI1 expression may be lost. Although there are no standard guidelines for treatment, in patients with resectable tumors, adjuvant therapy may be also beneficial. Since the prognosis is very poor in patients with unresectable tumors, careful assessment of resectability is very important. ABSTRACT: Undifferentiated pancreatic carcinomas are rare malignant tumors of the pancreas that are very aggressive and challenging to diagnose. The WHO categorizes them into undifferentiated osteoclast-like giant cell, sarcomatoid, and rhabdoid pancreatic carcinomas. Patients present with nonspecific symptoms such as jaundice, vague abdominal or back pain and itchy skin. Their histological characteristics include positive pan-cytokeratin mononuclear pleomorphic cells, osteoclast-like giant cells and CD68. Patients may have KRAS, TP53 and SMAD4 alterations, homozygous deletions of CDKN2A and CDKN2B, as well as INI1 deficiency. Surgical resection is the only curative treatment. Patients may benefit from postoperative adjuvant therapy. There are no widely accepted guidelines specific to this type of tumor; however, some chemotherapy regimens may be promising. The patient prognosis is mostly poor, especially in patients with unresectable tumors. However, several studies have shown patients achieving long-term survival with adjuvant therapy. In conclusion, although undifferentiated pancreatic carcinoma is rare and very aggressive, there is still potential for improved patient survival with proper diagnosis and treatment.