Advance Research, Early Detection and Treatment for Rare Tumors

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Welcome to the International Ovarian and Testicular Stromal Tumor Registry. The Registry collects clinical and biologic information about ovarian and testicular stromal tumors in hopes of learning more about treatment of these rare tumors.

Exciting news! In May of 2016 the International OTST and PPB Registries hosted the first ever international DICER1 Symposium at Children’s Minnesota, Minneapolis, Minnesota, USA

The inaugural DICER1 Symposium allowed a large group of medical professionals involved in cancer research and developmental biology research to assemble in one location to report on and discuss recent basic biology developments related to DICER1, and to discuss further surveillance and clinical management of the patients with DICER1-related conditions.

The conference included presentations of the unique histology of DICER1 tumors; genetics of the DICER1 syndrome; tumor biology of Sertoli-Leydig cell tumors and pleuropulmonary blastoma (PPB); pulmonary developmental mouse models recapitulating Type I PPB; miRNA studies including the critical role of the let-7 family miRNA; and clinical management of rare ovarian stromal tumors. In addition, posters were presented.

Attendees came from around the U.S., and from countries as far away as Moscow, Russia. Speakers came from Chil4dren’s Minnesota, Barnes/ Washington University in St. Louis, Children’s National Medical Center in Washington DC, Cincinnati Children’s Hospital, Children’s Hospital of Philadelphia, Children’s Medical Center in Dallas TX, McGill University in Montreal, Canada, SickKids Hospital in Toronto, Canada, Institute Curie in Paris, France, and Westphalian Children’s Center in Dortmund, Germany.

August 5, 2021
6th Annual International PPB/DICER1/OTST Registries Family Meeting


6th annual 
International PPB/DICER1/OTST Registries
Family Meeting

Please join us for a virtual event as we share the latest updates on pleuropulmonary blastoma (PPB), DICER1-associated tumors and ovarian and testicular stromal tumors. 


Date and Time

Thursday, August 5, 2021
9 a.m. – 2 p.m. CST



Virtual event

To register for the virtual meeting:

1.   Follow this link:
2.   Click on ‘Register’
3.   Fill out your information and you will receive a confirmation email with virtual event instructions

For questions, please contact This email address is being protected from spambots. You need JavaScript enabled to view it.


May 14-15, 2016
DICER1 Symposium for healthcare professionals


This two day conference will be held at the Minneapolis campus of Children’s Minnesota and it will focus on the biologic, clinical and translational aspects of the multidisciplinary work in the field of tumors related to DICER1, and the need for better treatment options which are necessary to cure the worst types of PPB. This symposium will promote collaboration between rare tumor groups around the world and the PPB and OTST Registries.



Saturday, May 14th, 2016 from 7:30 am - 5:30 pm
Sunday, May 15th, 2016 from 7:30 am - Noon



Children's Minnesota Education Center
2525 Chicago Ave S
Minneapolis, Minnesota 55404


Listen to Michael, Megan & Andrew's OTST & PPB story:

 Michael and Andrew's Story


St. Baldrick's Foundation (Registry sponsor) article highlighting an OTST family:

Research Funded by St. Baldrick's Leads to Early Detection of Infant's Cancer

Local and national outlets: Sharing the story of Children's cancer and blood disorders expertise


August Blog

The 29th annual Pine Tree Apple Tennis Classic raised more than $200,000 for Childhood Cancer Research and the International OTST Registry!!! Thank you to all who supported this amazing event. Stay tuned for our 30th next year!

The Ovarian and Testicular Stromal Tumor (OTST) Registry has grown tremendously thanks to donations from foundations, grants, and individuals worldwide. Financial gifts in any amount are always appreciated and will help ensure that families and health care providers will benefit from the Registry for years to come.

For questions about donating please contact:

Annie Waters Director of Annual Giving
The Foundation of Children's Hospitals and Clinics of Minnesota
2910 Centre Pointe Drive
Roseville, MN 55113USA
(W) 651-855-2821
(C) 763-438-1354

To make donations now, please do one of the following:

  • Go to and
    • Click on “Give Now”. Our online giving form will appear.
    • To make a gift to OTST, please scroll down to “other” in the designation field and
    • Type “OTST” into the box that appears.

  • Call us at 651-855-2800 to make a gift by phone. Be sure to let us know that your gift is to support OTST.

  • Make your check payable to The Foundation of Children’s Hospitals and Clinics of MN and be certain to write "OTST" in the memo line. Mail your check to:

      The Foundation of Children’s Hospitals and Clinics of Minnesota
      2910 Centre Pointe Drive
      Roseville, MN 55113

      Children’s Hospitals and Clinics of Minnesota is a non-profit organization. All donations are tax deductible.