Clinical Challenges & Images in Gastroenterology

A Diagnostic Guide

Ng, Siew C, Chan, Heyson CH, Lui, Rashid NS

• Publisher: tfm Publishing Ltd
• Year: 2018
• Print ISBN:
  9781910079034
• eBook ISBN:
  9781910079041
• Topic: Medicine
• Subtopic: Medical Theory, Practice & Reference

Digestive diseases have always been a major threat to global health. Despite the rapid advances in various diagnostic modalities, many a time the final verdict can be elusive and present a diagnostic challenge for the attending doctor. Clinical Challenges & Images in Gastroenterology — A Diagnostic Guide presents 50 real-life cases to illustrate an evidence-based approach for the diagnosis, investigation and management of gastrointestinal diseases commonly encountered in everyday practice, with a special focus on the interpretation of endoscopic and radiological images. This book provides a pragmatic approach for medical students, residents, specialist trainees and specialists alike who have an interest in gastroenterology. Other healthcare providers, such as general practitioners, nurses and dieticians, will also benefit from these case illustrations. The authors of this book are based at the Institute of Digestive Disease, Chinese University of Hong Kong. This institute has contributed to major breakthroughs that have improved the clinical management of digestive diseases including, but not limited to, the advent of endoscopic therapies and minimally invasive surgery, molecular diagnostic tools for cancers and inflammatory bowel disease, and the development of novel treatments for acid-peptic disease and viral hepatitis.

Case 1

History

A 53-year-old Chinese man with previous good health presented with a 6-month history of diarrhoea, weight loss, poor appetite and malaise. Colonoscopy showed a 40cm long segment of cobblestoning, with circumferential narrowing and ulceration in the descending colon highly suspicious for colorectal malignancy (Figure 1.1). A left hemicolectomy was performed. Histology showed ulcer exudates with granulation tissue. It was negative for malignancy and tuberculosis. He was well for 3 months after the operation, but now presents again with increasing diarrhoea up to 3-4 times per day, together with painful swallowing and tongue pain.

What is your differential diagnosis?

The differential diagnosis includes Crohn’s disease, malignancy, tuberculosis of the intestinal tract and Behçet’s disease.

Physical examination

•Temperature 37.7°C, pulse 80 bpm, BP 120/75mmHg, SaO₂ 99% on RA.

•Mild pallor.

•Examination of the hands reveals no clubbing and normal-appearing palmar creases.

•On examination of the head and neck, there is a left tongue base mass with ulceration and right supraclavicular lymph nodes which are firm in consistency and around 1cm in size.

•Cardiovascular: HS dual, no murmur.

•His chest is clear on auscultation.

•Abdominal examination reveals a midline laparotomy scar. The abdomen is soft, non-tender, with no definite abdominal mass palpable.

•No signs of oedema.

Does this narrow your differential diagnosis?

Recurrence of colorectal malignancy is less likely in this context as metastatic lymph nodes will more commonly cause enlargement of the left supraclavicular lymph node, i.e. Virchow’s node (Troisier’s sign). However, the lymph nodes and tongue base lesion are also atypical for Crohn’s disease. Initial testing for tuberculosis is also negative and there are no other features suggestive of Behçet’s disease.

Investigations

•CBC:

-WBC 11.9 x 10⁹/L;

-haemoglobin 10.9g/dL (microcytic, hypochromic picture);

-platelets 348 x 10⁹/L.

•ESR 67mm/hr.

•CRP 64.5mg/L.

What other blood tests would you order?

•Liver and renal function tests.

•Bone profile.

•Iron profile. This shows an iron deficiency picture.

What do these laboratory data suggest?

These laboratory findings suggest active inflammation with suspected iron deficiency anaemia.

What imaging test would you order?

With the presence of a tongue base mass with ulceration, it is important to arrange for imaging to assess any deep tissue involvement. For better soft tissue resolution, magnetic resonance imaging (MRI) of the neck is arranged (Figure 1.2).

Please describe what you see

An MRI of the neck shows a left tongue base mass measuring 4cm x 2.7cm x 3.4cm, with unusual findings of ulceration and an exophytic frond-like appearance. There is also inferior extension involving the lower left lateral oropharyngeal wall and valleculae. Bilateral enlarged nodes in the upper, mid and lower internal jugular chains are also noted.

How would you proceed?

An excisional biopsy of the right neck lymph node should be arranged.

Histology shows multiple patches of necrosis surrounded by lymphohistiocytic infiltrate, superficially resembling necrotising granulomatous inflammation.

What is your differential diagnosis for necrotising lymphadenitis?

Infection

•Disseminated mycobacterium infection.

•Cat scratch disease.

•Yersinia infection.

Autoimmune

•Crohn’s disease.

•Vasculitis, i.e. eosinophilic granulomatosis with polyangiitis, granulomatosis with polyangiitis.

•Sarcoidosis.

•Kikuchi-Fujimoto disease.

Malignancy

•Lymphoma.

In view of the atypical history, physical examination and histopathological features, further immunostaining and investigations are done.

Immunostain for CD56 (natural killer NK cell marker) shows moderate numbers of small- to medium-sized lymphoid cells in the interfollicular zone, which are easily overlooked in light microscopy. These atypical lymphoid cells co-express for CD3 and CD2 but not CD5 and CD7, and are also highlighted with in situ hybridisation for Epstein-Barr virus (EBV) encoded RNAs.

Review of the original colonic resection also demonstrates lymphomatous infiltrates (Figure 1.3).

What is the diagnosis, and how would you proceed?

Overall, the features are mostly consistent with NK/T-cell lymphoma.

The next step would be for timely referral to an oncologist for further work-up and management.

Clinical pearls

•Although rare, extranodal NK/T-cell lymphomas are more common in East Asia and South America. It is an uncommon differential diagnosis for inflammatory bowel dis...

Table of contents

• Cover
• Title Page
• Copyright Page
• Contents
• Preface
• Abbreviations
• Acknowledgements
• Dedication
• Case 1
• Case 2
• Case 3
• Case 4
• Case 5
• Case 6
• Case 7
• Case 8
• Case 9
• Case 10
• Case 11
• Case 12
• Case 13
• Case 14
• Case 15
• Case 16
• Case 17
• Case 18
• Case 19
• Case 20
• Case 21
• Case 22
• Case 23
• Case 24
• Case 25
• Case 26
• Case 27
• Case 28
• Case 29
• Case 30
• Case 31
• Case 32
• Case 33
• Case 34
• Case 35
• Case 36
• Case 37
• Case 38
• Case 39
• Case 40
• Case 41
• Case 42
• Case 43
• Case 44
• Case 45
• Case index
• Index