Table 1.

Demographic, hematologic, and clinical data of cases of MS without blood or bone marrow involvement.

Cases	Age/ Sex	Initial Site	Histopathology of the Mass	Flow cytometry and immunohistochemistry	Primary Therapy	Outcome
1	44/F	small bowel	Extensive infiltration of small bowel by intermediate to large sized blast cells with variably prominent nucleoli, extending from the mucosal to the serosal surface. Focally, tingible body macrophages imparted a ‘starry sky’ appearance. Many neoplastic cells revealed fine granules, and eosinophilic myelocytes were noted throughout the biopsies, consistent with MS, FAB M4eo.	Positive for CD45 (leukocyte common antigen), CD34 and the myeloid marker CD33. Strong expression of myeloperoxidase (MPO), CD43 and CD117. Scattered TdT positive cells, no expression of B- or T-cell markers.	Cytarabine, Daunorubicin, Etoposide	Sustained remission for over 5 years.
2	83/M	scrotum	Diffuse proliferation of medium sized cells with a high mitotic rate and blast-like appearance with fine chromatin; findings consistent with MS with expression of monocytic markers.	Blasts with a monocytic profile: CD15+, CD11b+, CD13+, CD33+, HLA-DR+, CD38+, CD56+; 20% of cells coexpressed CD15 and CD34 by flow cytometry. The cells revealed immunoreactivity for CD43 and vimentin, lysozyme, CD14 (weak) and CD68, and were negative for B- and T-cell markers, CD117 and MPO.	Gemtuzumab ozogamicin	Relapsed and died of infection.
3	62/F	left breast	Sheets of blasts with high nuclear-cytoplasmic ratio, vesicular chromatin, and prominent nucleoli in a background of geographic necrosis and numerous tingible body macrophages, imparting a "starry sky" appearance. Consistent with MS with monocytic/myelomonocytic differentiation.	CD45 (dim), CD34 (partial), CD13, CD33+, CD117+, CD15+, CD7+, and HLA-DR+. Strong immunoreactivity for CD68 and lysozyme with focal positivity for CD117 and CD34. Scattered MPO positivity. CD20 and CD3 negative.	Daunorubicin Cytarabine + Sorafenib	Relapsed and died of progressive disease.
4	42/F	clavicle	Sheets of blasts with vesicular chromatin.	CD45+, CD33+, CD43+, MPO+, CD68+, CD34-, CD56-, CD14-. Negative for cytokeratin, AE1/AE3, CAM 5.2, EMA, S100, TLE1, PAX5, CD20, CD3 and CD5.	HiDAC+ Mitoxantrone	Early local relapse; in remission after HSCT.
5	25/M	mediastinal mass	Consistent with MS.	Strong aberrant CD56 and CD7 expression.	Cytarabine, Daunorubicin, Etoposide /HSCT	Early local relapse; died from HSCT complications.
6	76/M	testis	Infiltration by blastoid cells of the testis, epididymis, rete testis and proximal spermatic cord into the tunica albuginea, with a negative tumor margin in the spermatic cord.	Positive for CD33 and CD68 and negative for CD20 and CD79a.	Patient refused therapy	The patient died from progressive disease.

HSCT- hematopoietic stem cell transplantation