The hot PET

October 24, 2015 By: Monzur Ahmed

Figure 1 | FDG PET-CT SCAN showing two areas of increased activity in the descending colon (arrow).

Figure 2 | Two polyps seen at colonoscopy in the descending colon (DC1 and DC2) measuring 15mm and 50mm in diameter, respectively.

Monzur Ahmed is a consultant gastroenterologist in the Department of Gastroenterology, Good Hope Hospital, Birmingham, UK. He graduated with BSc (Hons), MBChB in 1987 from the University of Birmingham, UK. He obtained an MD in 1997 for his research into viral hepatitis and was appointed as a consultant in 1999. He has an interest in advanced therapeutic endoscopy and leads the Trust’s Bowel Cancer Screening Programme.

The hot PET

Hot spots in the descending colon. What would you do with the polyps found on subsequent colonoscopy?

A 72-year-old man previously presented with obstructive bowel symptoms. He was diagnosed with mantle cell lymphoma—a type of non-Hodgkin lymphoma—with involvement of the rectosigmoid junction and terminal ileum.

He underwent a left hemicolectomy and resection of the terminal ileum followed by chemotherapy (fludarabine, mitoxantrone, dexamethasone and rituximab). After treatment he went into prolonged remission and follow-up colonoscopies 5 years and 7 years later were both unremarkable. The findings of a gastroscopy and capsule endoscopy were also normal 7 years after treatment, at which time the patient was asymptomatic with normal blood results. His haematologist requested a surveillance FDG PET-CT scan, which demonstrated a hot spot in the descending colon (figure 1). A further colonoscopy was carried out and showed 2 polyps in the descending colon (figure 2; DC1 [15mm] and DC2 [50 mm]). The ileocolonic anastomosis and neoterminal ileum were both unremarkable.

 

WHAT WOULD YOU DO WITH THESE POLYPS?

a)     Ignore them, as they are inflammatory.

b)     Take biopsy samples only.

c)     Perform standard snare polypectomy.

d)     Organise an endoscopic mucosal resection (EMR).

e)     Organise an endoscopic submucosal dissection (ESD).

Discussion

The polyps found in the case patient are likely to be recurrent gastrointestinal mantle cell lymphoma (MCL). To confirm the diagnosis, biopsy samples must be taken and immunohistochemistry performed. In this case immunohistochemistry indeed confirmed MCL. The polyps were lymphomatous submucosal lesions that were not suitable for endoscopic resection.

MCL is a type of mature B-cell non-Hodgkin lymphoma (NHL) that comprises 3–10% of NHLs in Europe and the USA.1,2 In MCL, the malignant cells are thought to originate from marginal-zone peripheral-blood memory B cells.3 The median age at presentation is 68 years and there is a male preponderance. In 75% of cases, patients with MCL present with lymphadenopathy, whilst 25% have extra-nodal disease. Common extra-nodal sites include the spleen, bone marrow, Waldeyer’s ring, gastrointestinal tract, breast, pleura and orbit.

MCL can involve any region of the gut and in one series of 31 cases, gut involvement was as follows: stomach (57%), duodenum (52%), jejunum/ileum (87%), colon (90%) and rectum (65%).4 In 28 of 31 cases lymphomatous submucosal nodules producing polypoid lesions were found in both the small and large bowel. These polypoid lesions may be seen at endoscopy (as was the case here) and measure from 2mm to several cm in diameter. Some of the polyps may be ulcerated. The polyps can involve more than one segment of the gut with or without normal intervening mucosa. Immunohistochemistry is essential to distinguish MCL from other small B-cell lymphoid proliferation.5 Peripheral and gastrointestinal MCL has a characteristic phenotype: CD20+, CD5+ and cyclin D1+ and CD10.

Primary MCL of the gastrointestinal tract carries a poor prognosis. Combination chemotherapy and immunotherapy remains the main treatment modality with or without high-dose therapy with haematopoietic stem-cell transplantation.6 Surgery is usually not of benefit but may be necessary in patients with bowel obstruction or intractable bleeding. Radiotherapy is normally reserved for palliation. Therapy for MCL is not curative and virtually all patients will have refractory or recurrent disease. Treatment of recurrent MCL involves salvage chemotherapy, preferably in the context of a clinical trial.

 

References

  1. Anderson JR, Armitage JO and Weisenburger DD. Epidemiology of the non-Hodgkin’s lymphomas: distributions of the major subtypes differ by geographical locations. Non- Hodgkins Lymphoma Classification Project. Ann Oncol 1998; 9: 717–720. 
  2. Zhou Y, Wang H, Fang W, et al. Incidence trends of mantle cell lymphoma in the United States between 1992 and 2004. Cancer 2008; 113: 791–798.
  3. Bertoni F and Ponzoni M. The cellular origin of mantle cell lymphoma. Int J Biochem & Cell Biol 2007; 39: 1747–1753. 
  4. Ruskone-Fourmestraux A, Delmer A, Lavergne A, et al. Multiple lymphomatous polyposis of the gastrointestinal tract: prospective clinicopathologic study of 31 cases. Groupe D’etude des Lymphomes Digestifs. Gastroenterology 1997; 112: 7–16.
  5. Ruskone-Fourmestraux A and Audouin J. Primary gastrointestinal tract mantle cell lymphoma as multiple lymphomatous polyposis. Best Practice & Research Clinical Gastroenterology 2010; 24: 35–42.
  6. McKay P, Leach M, Jackson R et al. Guidelines for the investigation and management of mantle cell lymphoma. Br J Haematol. 2012; 159: 405–426.

     

Answer

Correct answer: b. 

 

 

About the author

Monzur Ahmed is a consultant gastroenterologist in the Department of Gastroenterology, Good Hope Hospital, Birmingham, UK. He graduated with BSc (Hons), MBChB in 1987 from the University of Birmingham, UK. He obtained an MD in 1997 for his research into viral hepatitis and was appointed as a consultant in 1999. He has an interest in advanced therapeutic endoscopy and leads the Trust’s Bowel Cancer Screening Programme.

 

Comments

Stefania Chetcuti Zammit, October 28, 2015 12:59
c
Pieter-Jan Cuyle, October 26, 2015 18:26
B - very likely to be recurrent lymphoma
Leonardo Henry Eusebi, October 26, 2015 12:51
B
Would take biopsy, could be a relapse of the lymphoma
Jose Guillain Esteban Cataluna, October 26, 2015 05:56
D
Christian, October 26, 2015 01:22
D
Shivkumar Budihal, October 25, 2015 23:49
D EMR
Ronaldo, October 25, 2015 23:44
D
Mustafa, October 25, 2015 19:50
B, biopsy from top of the polyp, though it is not recommened before EMR.
Iradj, October 25, 2015 18:57
E
Panagiotis, October 25, 2015 18:04
E) Going on theory this should be the best option both to get a complete resection and a valid histological response, pet doesn't show other hotspots so (if I am right) lymphonodal metastasis are less likely, (their presence would be a controindication on endoscopic therapy)

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