Case of the Week #218

28 September 2011 Case of the Week #218

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Thanks to Dr. Oluyomi Asojo, University of Cincinnati, Ohio, for contributing this case. To contribute a Case of the Week, follow the guidelines on our Case of the Week page.

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CancerTYPE IDs database includes 2,206 tumors from multiple tumor banks, selected to provide broader and deeper representation of the heterogeneity of tumors. The 92-gene assay does not overlap with IHC markers, providing complementary data to standard tumor diagnosis.

CancerTYPE ID uses real-time reverse transcription polymerase chain reaction (RT-PCR). A very low copy number of RNA molecules can be detected, thus reducing the sample tissue required for testing. Testing is conducted and results are generated at bioTheranostics' CAP-accredited, CLIA-certified laboratory.

For more information, click here.

(1) To encourage a wider display of pathology related books on our Books pages, we are pleased to announce a new low price of $100 to post any pathology related book, with a link to the publisher. We will post the book on the appropriate books page, as well as on the New Books and Author pages. We will also include it in our Website News / New Books email. There is a 20% discount for posting 3 or more books. There is no charge to post a book which is sold through Amazon.com

(2) As a result of CAP '11 suggestions, we are working on: (a) finishing the Home Page Topic search by October 31, 2011; (b) more frequent reviews / updates of topics (ongoing); (c) developing a new format for viewing the website on an iPad or Smartphone; (d) possibly developing more social media discussions. Let us know what you think.

(3) Thanks to Dr. Perry Cohen, Montefiore Medical Center of the Albert Einstein College of Medicine, for his suggestion to post Cases of the Week by Category without a diagnosis, which has now been done.

(4) We posted an article on our Management Page, How to Gain a Better Managed Care Contract for your Independent Laboratory, by Mick Raich, Vachette Pathology, click here.

Clinical History:

A 35 year HIV+ man had diffuse lymphadenopathy (retroperitoneal, paraaortic, supraclavicular, inguinal and mesenteric) and increased FDG uptake on PET CT. His left supraclavicular node was 3.1 cm. A CT guided biopsy of a retroperitoneal lymph node was performed.

Micro images:

Mycobacterial spindle cell pseudotumor of lymph nodes is a disorder associated with HIV+ patients, often with involvement of many sites. It may also affect infants after bCG vaccination (Zhonghua Bing Li Xue Za Zhi 2001;30:89) or occur post-transplant (Am J Clin Pathol 1985;83:524).

Morphologically, the lymph nodes show a partial or complete effacement with a storiform pattern of bland spindle cells, some with vacuoles. There are also numerous vessels lined by plump endothelial cells, plasma cells and lymphocytes. There are no multinucleated tumor cells and no foamy histiocytes. The spindle cells are actually macrophages with large numbers of mycobacteria (Am J Surg Pathol 1992;16:276). Intraoperative touch imprints demonstrate numerous intracellular organisms (Arch Pathol Lab Med 1995;119:811).

The tumor cells are immunoreactive for CD68, S100 and AFB and negative for CD34:

The differential diagnosis includes:
● Kaposi's sarcoma: has slit-like spaces and mitotic figures; cytoplasm is not granular or acidophilic; spindle cells are CD31+ and CD34+, but negative for S100, CD68 and AFB (Am J Surg Pathol 1999;23:656)
● Smooth muscle tumor: positive for actin and desmin, negative for S100, CD68 and AFB

Treatment consists of antiretroviral therapy for HIV and antibiotics.

Nat Pernick, M.D., President
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