Desmoplastic small round cell tumour
| Desmoplastic small round cell tumour | |
|---|---|
| Diagnosis in short | |
 DSRCT. H&E stain. | |
|
| |
| LM | small (round) cells in nests with an undulating sharp border, road bands of paucicellular fibrous stroma |
| LM DDx | solid variant of alveolar rhabdomyosarcoma, embryonal rhabdomyosarcoma, other small round cell tumours |
| IHC | AE1/AE3 +ve, desmin +ve, EMA +ve, actin -ve, WT1 (N-terminal) -ve, WT1 (C-terminal) +ve, CD57 +ve. |
| Molecular | t(11;22) |
| Site | soft tissue lesions - typically retroperitoneum |
|
| |
| Clinical history | usu. young adults |
| Prevalence | very rare |
| Prognosis | poor |
| Clin. DDx | (metastatic) germ cell tumour, lymphoma |
Desmoplastic small round cell tumour, abbreviated DSRCT, is a rare malignant soft tissue lesion that tends to afflict young adults.
General
- Males > females.
- Usu. affects young adults.
- Typically retroperitoneal.
- Poor prognosis.
Clinics
- Rare cases in the CNS reported.
Microscopic
Features:[1]
- Broad bands of paucicellular fibrous stroma with:
- Small round cells in nests with an undulating sharp border.
- The small round cells lack distinct nucleoli and have scant cytoplasm; they are small round cell tumour cells.
Notes:
- Usu. abundant mitoses.
- +/-Necrosis.
DDx:
- Metastatic germ cell tumour (DDx of location and age).
- Embryonal RMS.
- It should be noted that DSRCT, like embryonal RMS, is +ve for desmin!
- Solid variant of alveolar RMS.
- Nests in alveolar RMS have round edges.
- Other small round cell tumours.
Images
DSRCT - intermed. mag. (WC/Nephron)
DSRCT - high mag. (WC/Nephron)
DSRCT - very high mag. (WC/Nephron)
IHC
Features:
- AE1/AE3 +ve.
- CAM5.2 usu -ve.
- Desmin +ve (strongly).
- EMA +ve.
- Actin -ve.
- WT-1 (N-terminal) -ve.
- WT-1 (C-terminal) +ve (nuclear staining).
- CD57 +ve.
- Synaptophysin focal, patchy +ve.
Molecular
See also
References
- ↑ Pickhardt PJ, Fisher AJ, Balfe DM, Dehner LP, Huettner PC (March 1999). "Desmoplastic small round cell tumor of the abdomen: radiologic-histopathologic correlation". Radiology 210 (3): 633–8. PMID 10207460. http://radiology.rsna.org/content/210/3/633.full.
- ↑ Lee YS, Hsiao CH (October 2007). "Desmoplastic small round cell tumor: a clinicopathologic, immunohistochemical and molecular study of four patients". J. Formos. Med. Assoc. 106 (10): 854–60. doi:10.1016/S0929-6646(08)60051-0. PMID 17964965.
- ↑ Lal DR, Su WT, Wolden SL, Loh KC, Modak S, La Quaglia MP (January 2005). "Results of multimodal treatment for desmoplastic small round cell tumors". J. Pediatr. Surg. 40 (1): 251–5. doi:10.1016/j.jpedsurg.2004.09.046. PMID 15868593. http://www.dsrct.com/JPS%20Article.pdf.