Clinical History A 59-year-old woman presented with dyspepsia and - PowerPoint PPT Presentation

IAP Congress – Jordan Mimics of Neoplasia in the GI tract Clinical History • A 59-year-old woman presented with dyspepsia and epigastric pain for a few weeks. • Upper endoscopy revealed minimal gastric mucosal irregularity. • A set of biopsies was taken.

Diffuse process of the lamina propria

Expansion of LP by an eosinophilic cellular infiltrate

Infiltrate present round inconspicuous nuclei & granular / fibrillar eosinophilic cytoplasm

Dif Differential Diagnosis of an erential Diagnosis of an Inf Infiltr ltrative Pr tive Process ocess Infectious MAI Whipple (Malakoplakia) Foreign material Xanthoma Glycolipid storage diseases Granular cell tumor ? Neoplastic (epithelial) Gastric Adenocarcinoma Metastatic CA (Breast) Hematopoeitic diseases Lymphoma NK Cell enteropathy Lymphoma Rosai Dorfmann Russell body gastritis

AFB MAI

Tropheryma Whipplei Whipple’s disease

CD68 Gastric Xanthoma

GI Manifestations of Systemic Diseases CD68 Gaucher’s disease

Granular cell tumor

Alcian Blue Signet Ring Cell Gastric Cancer

Poorly cohesive gastric cancer

CDX2 Metastatic lobular breast CA, Malignant melanoma ought to be ruled out

NK-Cell enteropathy

NK-Cell enteropathy CD56 Granzyme CD3

Russell Body Gastritis

Crystal Storing Histiocytosis

Histiologic Characteristics of Crystal Storing Histiocytosis • Infiltration of lamina propria by large, oval, polygonal & occasionally, spindle cells. • Abundant eosinophilic cytoplasm and small eccentric nuclei. • Cytoplasm is packed w/ elongated, rectangular, needle-shaped/ fibrillary crystalline inclusions. • Inclusions are approximately 5–20 nm long and are frequently arranged in parallel arrays. Histopathology 2007, 51, 114–137; Am J Surg Pathol 2018;42:1317-1324; J Pathol Transl Med 2017; 51: 341-351; Clin J Gastroenterol 2013:6:237–242

• Monoclonal immunoglobulins are phagocytosed by histiocytes & crystallized when broken down by lysosomes. The acidophilic crystals grow and accumulates in RER – Most cases are Kappa restricted [more degradation resistant than lambda light chain?] • CD79a Inclusions may not react IgG with Kappa/Lambda IHC – altered antigenicity? – insufficient Ag quantities? • ISH also negative because of lack of intact mRNA Histopathology 2007, 51, 114–137; Am J Surg Pathol 2018;42:1317-1324; J Pathol Transl Med 2017; 51: 341-351; Clin J Gastroenterol 2013:6:237–242

Transmission EM appearance of CSH Intracytoplasmic crystals – some free and and others packed in bundles showing a fibrillary appearance in dilated endoplasmic reticulum Histopathology 2007, 51, 114–137; Am J Surg Pathol 2018;42:1317-1324; J Pathol Transl Med 2017; 51: 341-351; Clin J Gastroenterol 2013:6:237–242

Crystal Storing Histiocytosis • Rare condition • Systemic or described in isolation in: – Lung, – Thymus – Lymph nodes – Kidney, – Thyroid & Parotid glands – Cornea – Stomach

~10% of CSH are not associated with B lymphoproliferative disorders • Immune mediated disease: Rheumatoid arthritis, Crohn’s disease • Systemic mastocytosis • Also – Chronic clofazimine – Charcot-Leyden crystal associated [eosinophilic colitis; cutaneous hypereosinophilic Sd.]

Endoscopic appearance of gastric CSH • Incidence of 8% in gastric lymphoma • Also associated with: – H. pylori infection – thymic lymphoma – multiple myeloma – Sjogren’ syndrome