Table 1.

Key clinical characteristics, histopathology, and molecular pathology of three DICER1-associated sarcomas

Demographics			Clinical characteristics			Histopathology								Molecular pathology				Outcomes
Patients	Age at diagnosis	Gender	Site of sarcoma	Other DICER1-associated conditions	Family history	Gross features	Rhabdomyoblastic differentiationa	Anaplasia	Chondroid/myxoid differentiation	Bone/osteoid formation	Immunohistochemical stains		Initial diagnosisb	DICER1 mutation(s)		Other genetic alterations	Final diagnosis
											Positive	Negative		Somatic	Germline
Patient 1	5	F	Ovary	None	Mother: benign thyroid nodules Paternal grandmother: thyroid cancer Paternal great uncle: Brain tumor (DOD)	Oophorectomy specimen: fragments of torsed and ruptured ovarian tissue, measuring 8 × 6 × 4.8 cm in aggregate	Present	Present	Present	Present	Desmin myogenin SALL4	AE1/AE3 inhibin A calretinin INI1 (retained) GFAP NKX2.2 SOX10	High-grade pleomorphic sarcoma	c.2223_2230del; p.S742T*16 c. 5425G>A;p.G1809R	c.2223_2230del; p.S742T*16	None	DICER1-associated ovarian sarcoma	Alive; radiographic remission 13-months off therapy
Patient 2	16	F	Peritoneum	Papillary thyroid microcarcinoma	None	Oophorectomy and peritoneal mass specimens: unknown Autopsy: multiple tumor nodules, measuring 3.5–4.8 cm in peritoneum and omentum. Extensive abdominal, subdiaphragmatic, and mediastinal lymphadenopathy was also identified.	Present	Present	Present	Present	Peritoneal mass: desmin Myogenin MyoD1 p53: 20% of the SRBC Autopsy: desmin S100 (partial)	Peritoneal mass: calretinin CD10 Cytokeratin 7 EMA Inhibin A WT1 Autopsy (post chemotherapy): myogenin WT1 CK7 CD34 CD10 CD68	Outside hospital: mature cystic teratoma Re-review at our institution: adenosarcoma with rhabdomyosarcomatous overgrowth	c.3682C>T;p.Q1228* c.5428G>T;p.D1810Y	Not tested	NRAS: vc.181C>A; p.Q61K	DICER1-associated peritoneal sarcoma	DOD
Patient 3	4	M	Brain	None	Maternal aunt: unknown cancer	Hemicraniectomy specimen: tumor tissue fragments measuring 2.3 × 2.1 × 0.9cm in aggregate	Present	Present	Present	Absent	Desmin Myogenin MyoD1 (focal) TLE1 BCOR and CD99 (patchy, weak) Ki67 > 95%	INI-1 (retained) BRG1 (retained) SMA AE1/AE3 GFAP EMA Synaptophysin Olig2 S100	Primitive embryonal tumor with embryonal rhabdomyosarcomatous elements	c.5439G>C;p.E1813D	Not tested	GLI2c IGFR1c TSC2c LOH 11p15.5 Loss 14q32.12 Gain 8q11.21	DICER1-associated primary intracranial sarcoma	DOD

F female, M male, DOD died of disease, SRBC small round blue cell, LOH loss of heterozygosity

^aIncluding small round blue cells and spindle cells supported by IHC

^bPrior to molecular testing, based solely on histopathologic review

^cVariants of unknown clinical significance