The open biopsy was taken from 13 yrs old boy popliteal deep seated 15cm tumor, spreading along large vessels and infiltrating muscles. The inguinal lymph node was biopsed too. CT reveals multiple lymph nodes (visceral and paraaortal) and 15cm tumor in the popliteal area without bone destruction ("lymphoma like picture" on CT).  
HISTORY: 1 month ago the tenderness and pain inth left feet. ESR and CRB were elevated. The transitory fever was noticed. The vasculopathy was suspected. The patient is obese (88kg). Any B symptoms today present.  
HISTO: 1 MUSCLE: There are small infiltrates of high proliferative rate small blue tumor cells in the stratiated muscle. The apoptotic bodies, nuclear ireegularities are prominent. 2. NODE (fragmented): The lymph node is infiltrated from sinus side by pleomorphic cells with irregular nuclei and scant-medium bluish clear cytoplasm. THERE ARE ANY SIGNS of plasmablastic appearance.  
IH: ALK1(+/++) 95%, TdT/CD34(-), EMA/PanCK(-), CD3/CD20/CD30/LCA/CD68/CD79a/MPO(-), CD99(-), CD138(-), Ig kappa (+/+++)> Iglambda (???), Mum1(-), CD4/GranzymB/CD8(-), Bcl6/CD10(-). Ki67 proliferative fraction 90% (++), PAX-5(-/+)(single nuclei +/- ), HMB45/S100(-), Desmin (+/++)(IN PERIPHERY OF THE SECTION MAINLY and dott like cytoplasmic in central part in the single cells) .  
PENDING: AsmActin, MyoD1, Myogenin, Vimentin.  
 
The first idea was ALCL, but CD30 seems to be negative...  
SO...PROPOSED DIAGNOSIS: HIGH GRADE LYMPHOMA, MOST PROBABLY DLBCL WITH ALK1 EXPRESSION.  
FINAL DIAGNOSIS: ALVEOLAR RHABDOMIOSARCOMA.  
 
QUESTION: the strange IH profile, maybe due to technical reasons.  
 
NOTE: The HISTO quality is SUBOPTIMAL.  
Due to inconclussive immunophenotype I have had an idea about effaced immunogennity of tissue or lab quality problems.  
 
Thank you for comments.

abaur 2007-08-23 11:09	These results are not sufficient for deducing a lymphoma. The morphology of the tumor cells and the sinusal tophography of the LN infiltration in my eyes would rather be consistent with an embryonal rhabdomyosarcoma. The next step on this poor materail would be testing fo the basic markers Vimentin and CD45, and going on with myogenin if CD45 appears to be negative. A. Baur Chaubert
ugnius 2007-08-23 11:14	Thanx. I'm filling the case form now:)
ugnius 2007-08-23 15:23	The primary idea of ALCL leads to erroneous way... I just now have found info, that sometimes rhabdomyosarcomas aberantly express: CK, NF and (SIC!) CD20, Igs and other B lineage markers. Maybe positivity to ALK1 is another example of this feature.
ugnius 2007-08-23 15:26	..and maybe SOLID VARIANT of alveolar rhabdomyosarcoma must be postulated (after MyoD1, Myogenin results for sure). I will provide the primary tumor picture (additional excisional material arrives due to massive edema of the leg). Beacause in the first biopsy we have only small nidus of the tumor in the muscle.
hurwitz 2007-08-23 16:32	I absolutely agree with Audrey. I also would consider the diagnosis of embryonal Rhabdomysoarcoma as the most likely one. The Desmin+ seems to be real and the stronger reaction in the periphery might be due to poor fixation in the central areas.   Morphology and immunohistochemmistry are rather against lymphoma.   Regarding ALK positivity: According to an Immnoquery 50%/20 cases of PNET, and 30% /47 cases of Rhabdomyosarcoma were ALK+.   See also: Hum Pathol. 2004 Jun;35(6):711-21, Li XQ, Hisaoka M, Shi DR, Zhu XZ, Hashimoto H: Expression of anaplastic lymphoma kinase in soft tissue tumors: an immunohistochemical and molecular study of 249 cases.
ugnius 2007-08-23 16:53	Thank you for help and supporting. I hope MyoD1/Myogenin will provide some add info tomorrow afternoon.
Mueller-Hermelink 2007-08-23 22:50	Just another facette: I fully agree - this is certainly not ALCL.CD56 is typical for rhabdomyosarcoma- I would believe that alveolar is more probable , but would perform translocatoion FISH or PCR. I missed the PAS stain which would be negative in ALCL and positive in Rhabdomyosarcoma and I don't believe the PAX5 stain - probably not tumor but background cells.
torlakovic 2007-08-24 02:57	Despite the lack of desmoplastic stroma, I would like to see that desmoplastic small round cell tumor (DSRCT)was excluded. I would also not give up this possibility despite negative results with panCK. Would repeat CK, do NSE, or few other markers, but would rely only on RT-PCR for EWS-WT1 fusion transcripts characteristic of this neoplasm.
ugnius 2007-08-24 09:01	Thank you. the PAS pictures are attached- it seems to be negative (some faintly pos cells)...
ugnius 2007-08-24 09:15	Add note: some peripheral parts are crushed in "alveolar" pattern. Regarding desmoplastic tumor: CD99 and Panck (-).   We just now introducing Ewings familly diagnostic PCR panel so really it's impossible for the moment. We are just waiting add muscle markers with hope...
ugnius 2007-08-24 09:26	Appologies for mistake: it seems some scattered cells are positive for PanCk like in the Desmin stain.
ugnius 2007-08-24 12:27	Another strange "aberrant" thing: Methyl green pyronine (Brashe) stain seems to be slightly positive:)(Photos)
kunze 2007-08-24 12:49	Rhabdomyosarcoma (rather alveolar than embryonal) seems to me most likely but needs to be confirmed by specific markers (MyoD1 etc.). CD56 is usually positive in rhabdomyosarcomas and expression of ALK-1 as well as some scattered CK-positive cells don't argue against the diagnosis.
ugnius 2007-08-24 16:36	The last point: MoD1/AsmActin(-), Myogenin+ undoubtedly. Its interesting, that chromograninA reacts like ALK1. CD57+ is prominent.
ugnius 2007-08-28 17:14	REPEATED BIOPSY FROM PRIMARY TUMOE: Desmin(+) 40%, MyoD1(+) 80%, Myogenin (+) 95%, CD99(-), PanCK(++)<5%, NSE (single cells esp. in perinecrotic areas).   This biopsy FINALLY reveals MyoD1 faint but positivity.   Thank you for collaboration. some new pictures are appended.
hurwitz 2007-09-01 21:26	Finally the case can be concluded as alveolar rhabdomyosarcoma.   Thanks for this interesting case and the contributions to the discussion.   points of special interest: ALK1+,CD56+ CD57+.
	» Add comment (Login)