Home   Case of Week Home   Jobs  Conferences   Fellowships   Books

12 June 2013 - Case of the Week #276

All cases are archived on our website. To view them sorted by number, diagnosis or category, visit our Home Page and click on the Case of the Week button on the left hand side. To subscribe or unsubscribe to the Case of the Week or our other email lists, click here.

Thanks to Dr. Carolina Martinez Ciarpaglini, University Clinic Hospital of Valencia (Spain), for contributing this case and the discussion. To contribute a Case of the Week, follow the guidelines on our Case of the Week page.

Introducing 23 New Rabbit Monoclonal Antibodies: MSH2, CD25, RRM1, and others.

Epitomics is releasing 23 new EP Clones, high quality antibodies for anatomic pathology.

Our collection of EP Clones now includes new breast cancer markers: Aurora B and Mammaglobin; new Lymphoma markers CD25, RRM1, as well as various other Colon and Lung Cancer targets. Rabbit monoclonal antibodies (RabMAbs®) are the product of true rabbit-rabbit hybridomas. The inherent qualities of the rabbit immune system allow us to select antibodies which include: 1) stronger binding affinity and 2) higher specificity.

Click here to view our new products or visit us at epitomics.com/diagnostics for our complete product listing.


Website news:

(1) Our Feature Page for June highlights Diagnostic Testing / Reagents and includes Advanced Cell Diagnostics, Inc. (ACD), bioTheranostics, Epitomics - an Abcam Company, Leica Microsystems, and Ventana Medical. We also have a new Mystery Case on the right side of the Home Page.

(2) In May 2013, we again had record traffic, with 400,261 visits and an average daily traffic of 12,911 visits.

(3) Major image update! We are in the process of adding about 10,000 images from AFIP (third series) along with over 10,000 images from Dr. Mark Wick. Additionally, for AFIP images with long captions, to make for easy viewing we are adding the caption to the image. Take a look at the Images from AFIP in the Micro images section of Hashimoto's thyroiditis and let us know what you think.

(4) Do you have subspecialty expertise and want to be a resource for pathologists worldwide? PathologyOutlines.com, the leading online reference for pathologists, with 13,000 daily visits, is seeking reviewers for many of its 6,600+ topics. Reviewers play a vital role in making the site credible, comprehensive, and current. If you are interested, please take a look at our new Reviewer Resources chapter, with a new Reviewer FAQ page to answer your questions about being a reviewer and a Chapters in Review page that shows all of our chapters in need of review. We have made several changes to our review process and are currently looking for reviewers only for the chapters listed.

(5) We have finished converting all of our Books pages (with 1100+ books) to a cleaner, easier to read format that includes the title, publishing information, a short description, and pictures of the book covers. Throughout the process, we also combined some of the Specialty pages together and removed a few outdated ones. We will continue to add recently published books monthly to the individual Specialty pages, Books by Author and New books pages. Also, from now on, we will list all of the authors/editors that have contributed to each book as shown on Amazon.com. If you have any suggestions for books that should be listed on our pages, please email them to commentspathout@gmail.com. Books that are posted on Amazon.com are listed at no charge. To list a book that links elsewhere costs $100 per book.

(6) We have updated the Skin-melanocytic tumor chapter based on reviews by Christopher Hale, M.D.

Case of the Week #276

Clinical History:

An 11 year old boy presented with a left tonsillar mass present for three weeks. A biopsy was taken.

Micro images:

What is your diagnosis?


Embryonal rhabdomyosarcoma


The tumor cells were immunoreactive for actin, desmin, myogenin and myoD1:

Left to right: actin, desmin, myogenin and myoD1 staining

Embryonal rhabdomyosarcoma is a primitive soft tissue sarcoma with small blue cells resembling embryonic skeletal muscle. It is the most common rhabdomyosarcoma (RMS) subtype (65% of RMS cases), and usually occurs in children ages 3-10 years in the head and neck (nasal and oral cavities, orbit, ear), prostate or paratesticular regions. Subtypes include embryonal-NOS, anaplastic, botryoid and spindle cell. Embryonal-NOS is the most common subtype (75%), usually affecting boys. It peaks at ages 0-4 years (US National Cancer Institute).

The tumor consists of dense zones of undifferentiated, differentiating and well differentiated cells. A cambium layer (cells immediately beneath the epithelium) is present. Undifferentiated cells are blue cells with minimal wispy cytoplasm but no skeletal differentiation, and central nuclei. Differentiating cells have moderate amphophilic or eosinophilic cytoplasm, often fibrillar. They may have a tadpole shape, often with nuclei arranged in tandem. Well differentiated cells have cytoplasmic cross-striations.

Tumors cells, as in this case, are immunoreactive for actin, desmin, myogenin and myoD1. There may occasionally be immunoreactivity for S100 and CAM5.2. The differential diagnosis consists of other small blue cell tumors, such as lymphoma and neuroblastoma. All children with rhabdomyosarcoma require multimodality therapy with systemic chemotherapy and either surgery or radiation therapy. Overall 5 year surival is over 80%, although it is much less for those with metastatic disease (eMedicine).

Nat Pernick, M.D., President
and Palak Thakore, Associate Medical Editor
PathologyOutlines.com, Inc.
30100 Telegraph Road, Suite 408
Bingham Farms, Michigan (USA) 48025
Telephone: 248/646-0325
Email: NatPernick@Hotmail.com
Alternate email: NatPernick@gmail.com