Colon tumor
Mesenchymal tumors
Histiocytic sarcoma of colon

Authors: Raul S. Gonzalez, M.D. (see Authors page)

Revised: 29 November 2016, last major update November 2016

Copyright: (c) 2003-2016, PathologyOutlines.com, Inc.

PubMed Search: histiocytic sarcoma colon
Cite this page: Histiocytic sarcoma of colon. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/colontumorhistiocyticsarcoma.html. Accessed December 6th, 2016.
Definition / General
Essential Features
  • Rare primary sarcoma of the gastrointestinal tract featuring CD163 positivity
  • Can be mistaken for lymphoma with infiltrating histiocytes
Terminology
  • Previously also called "true histiocytic lymphoma"
Sites
  • Gastrointestinal tract most common location, after skin / soft tissue
  • Colonic examples are often distal (sigmoid / rectum)
Clinical Features
  • Median age 55 years, with no sex predilection (Am J Surg Pathol 2004;28:1133)
  • Symptoms include weight loss, abdominal pain and hematochezia
  • Postoperative outcome can vary from full recovery to death
Gross Description
  • Bulky exophytic mass with infiltrative margins
Micro Description
  • Sheets of large epithelioid cells with abundant eosinophilic cytoplasm, oval to irregular nuclei, vesicular chromatin, prominent nucleoli and distinct borders; cells may be binucleated, giant or spindled
  • Prominent inflammatory infiltrate (lymphocytes, eosinophils, neutrophils)
  • Often mitotic activity and necrosis
  • Regional lymph nodes generally involved
Micro Images

Images hosted on PathOut server:

Contributed by Dr. Raul Gonzalez, University of Rochester Medical Center (USA):

Low power

Abundant lymphocytes

High power

Multinucleated cells

Positive Stains
Electron Microscopy Description
  • Cells contain scattered lysosomes, consistent with histiocytic origin
Molecular / Cytogenetics Description
  • May show monoclonal IgH bands or IgH and TCR gamma gene rearrangements
Differential Diagnosis