7 April 2005 – Case of the Week #2


This is our second Case of the Week.  These cases can also be accessed by clicking on the Case of the Week button on the left hand side of our Home Page.  This email is only sent to those who requested to be on this list in writing or by email. 


To subscribe or unsubscribe, email NPernick@PathologyOutlines.com, indicating subscribe or unsubscribe from Case of the Week.  As always, we do not sell, share or use your email address for any other purpose.  We also maintain an email list to receive a biweekly update of new jobs added to our Jobs page, and three separate lists for Pathologists, Residency Directors or Fellowship directors who want to receive quarterly updates about our website.  You must subscribe or unsubscribe separately to these email lists.


We have no sponsor this week, but invite you to visit our expanded Books page, now with over 900 titles, many with book reviews (from the Home page, click on the Books button on the left hand side, or click here).  Books are sorted by logical topics (cytology, dermatopathology, hematopathology, etc.) and by author.  New books and reviews are added regularly. 


This case was contributed by Dr. Celso Rubens Vieira e Silva, Hospital Aliança, Salvador, Bahia, Brazil, who we thank for contributing to the education of pathologists worldwide.  We invite you to contribute a Case of the Week by sending microscopic images in JPG or GIF format, with a clinical history and any other images (gross, immunostains, EM, etc.) that may be helpful to NPernick@PathologyOutlines.com.  Please send comments to the same email address.



Case of the Week #2


A 53 year old woman underwent laparotomy for a benign pancreatic cyst and an enlarged spleen was noted.  It weighed 425 grams and measured 15 x 9 x 7 cm.  A splenectomy was performed.

Gross:  The spleen had an unencapsulated, but well circumscribed, 6.0 cm tumor, and was otherwise unremarkable.


Gross images: spleen with well circumscribed, dark-red tumor (right side); close-up of tumor


Micro images: representative section of tumor


Micro: The tumor was composed exclusively of red pulp elements.  No follicles or trabeculae were present.


(scroll down to continue)



















Diagnosis:  Splenic hamartoma




Splenic hamartoma, also called splenoma or splenadenoma, is rare, representing 0.2% or less of splenic surgical specimens.  It occurs in patients of any age, with no gender preference.  It is frequently an incidental finding of imaging studies, at surgery or at autopsy, but may also be associated with symptoms of hypersplenism, including thrombocytopenia.  It has a benign clinical course.


Grossly, it is a large, well circumscribed but unencapsulated, dark red, nodular lesion, often with hemorrhage.  It is composed almost exclusively of red pulp elements, and may have foci of extramedullary hematopoiesis, but there are no white pulp elements (i.e. no follicles or trabeculae).  The red pulp elements include sinusoids lined by littoral cells with a unique phenotype (CD8+, CD31+, CD34-), capillaries lined by usual type endothelium (CD8-, CD31+, CD34+) and small veins (CD8-, CD31+, CD34-).  The red pulp also contains histiocytes, antigen presenting cells, fibroblasts and pericytes.  Occasional cases may have scattered large, bizarre stromal cells, that appears to represent a degenerative and not a neoplastic change (AJSP 2005;29:109)


The differential diagnosis of splenic hamartoma includes hemangioma, which may be morphologically similar, but is CD8 negative, unlike the CD8+ littoral cells which are one of the components present in splenic hamartoma.

Additional references:

Case report of 45 year old white woman with heterotopic ovarian splenoma (Archives 2001;125:1483)



Nat Pernick, M.D.
PathologyOutlines.com, LLC
30100 Telegraph Road, Suite 404
Bingham Farms, Michigan (USA) 48025

Telephone: 248/646-0325
Fax: 248/646-1736
Email: NPernick@PathologyOutlines.com