The study included 39 patients aged 15 years or older with a diagnosis of PPL, and who had received treatment in 8 Italian institutions. The observation period was from January 2005 to December 2018.
The most common symptoms that patients initially presented with were abdominal pain (58%), jaundice (47%), symptoms characteristic of B-cell lymphoma including fever, night sweats and weight loss (31%), and duodenal obstruction (10%). In addition to high LDH levels, laboratory testing performed prior to treatment also showed elevated serum levels of pancreatic amylase in 58% of patients, but CA 19-9 was increased in only 6 of 22 (28%) evaluable cases. In addition, 5 patients (15%) tested positive for hepatitis B virus, 1 patient (3%) for hepatitis C virus, and none for HIV.
As the symptoms and localization are similar to other pancreatic malignancies, Dr Facchinelli explained that usually a fine needle aspiration is performed on suspicion of pancreatic adenocarcinoma. “Cytological analysis can only direct the diagnosis to a lymphoma but [it can] not confirm it and [can] not define a correct histotype,” he explained. “For this reason, if lymphoma is suspected, it would be important to obtain a histological sample and not a cytological one.”
Within this cohort, histopathological specimens were primarily obtained by percutaneous (41%) or endoscopic (36%) methods and via abdominal surgery in 23% of patients. Computer tomography showed that tumors had a mean size of 81 mm (range 20-180 mm) and were primarily located in the pancreatic head in 28 (72%) cases. Almost half of all patients (49%) were diagnosed with early-stage disease (Ann Arbor stage I and II) while 51% of patients were diagnosed with advanced stage disease (stage III and IV). Diffuse large B-cell lymphoma (DLBCL) was the most frequent (69%) histological diagnosis, and 2 patients with DLBCL were receiving immunosuppressive therapy for previous solid organ transplantation at the time of their diagnosis.
Treatment information was available for 34 patients, and most (65%) initially received chemotherapy alone, while 17% were treated with chemotherapy plus radiotherapy, 9% underwent debulking surgery (Whipple procedure) plus chemotherapy, and 3% had debulking surgery alone.
Poorer Outcomes With Surgery
The authors noted at a median follow-up of 36.6 months, the 2-year overall survival was 62% and 2-year progression-free survival was 44%. The median time to progression was 13.7 months; progression occurred within 14 months in 13 of 14 cases.
Overall survival differed significantly depending on treatment. Those who underwent chemotherapy, either alone or with radiotherapy, had a 2-year overall survival of 60% compared with 33% for patients who underwent debulking surgery plus chemotherapy (P =.032). Progression-free survival at 2 years was highest among patients treated with chemotherapy alone (57%), followed by chemotherapy and radiotherapy (40%), and surgery and chemotherapy (33%).
The treatment for PPL is different from pancreatic carcinoma, explained Dr Facchinelli. “In fact, in the case of lymphoma, surgical treatment should be avoided,” he said. “In our cohort of patients, surgery with or without chemotherapy was associated with a significantly worse overall survival. Patients treated with chemotherapy with or without radiotherapy had an overall response rate of 89%.”
A total of 8 patients (24%) died from lymphoma, while 1 patient (3%) died from an unrelated cause. At the time of last follow up, 25 patients (73%) were alive. Of the 32 patients with high grade disease, 3 (9.4%) experienced a central nervous system (CNS) relapse.
“PPL is rare, often high-grade, with symptoms and localization similar to those of other pancreatic malignancies,” the authors wrote. “The high CNS relapse rate reported by literature was confirmed in our cohort, and patients with high grade PPL should undergo CNS directed prophylaxis,” they concluded.
Facchinelli D, Sina S, Boninsegna E, et al. Primary pancreatic lymphoma: clinical presentation, diagnosis, treatment, and outcome [published online June 16, 2020]. Eur J Haematol. doi: 10.1111/ejh.13468