Myeloid Sarcoma

Abstract

Hematological malignancies can manifest as extramedullary soft tissue masses in relatively rare cases. The rarity of it causes a diagnostic and therapeutic challenge. One of the rarest manifestations is myeloid sarcoma (MS). MS develops as part of acute myeloid leukemia, myeloproliferative neoplasm, or myelodysplastic syndrome or at relapse, especially following allogeneic hematopoietic stem cell transplant. The tumor displays high myeloperoxidase expression, hence the color green, and is called chloroma. It most commonly appears in lymph nodes, skin and soft tissues, bone, testes, gastrointestinal tract, and peritoneum. Immunohistochemistry shows CD68-KP1 as the most commonly expressed marker, then myeloperoxidase, CD117, CD99, CD68/PG-M1, lysozyme, CD34, terminal deoxynucleotidyl transferase, CD56, CD61, CD30, glycophorin A, and CD4. Different chromosomal abnormalities including MLL rearrangement, t(8; 21), monosomy 7, trisomy 8, trisomy 11, trisomy 4, inversion (16), monosomy 16,16q deletion, 5q deletion, and 20q deletion were reported. Most of the literature about MS are case reports and small retrospective studies, thus there is limited clinical knowledge of the cases and their presentation and management plans. Here, we provide a review of what has been reported in the literature about MS in the light of our experiences.

Gastric Myeloid Sarcoma

“…This uncommon condition mostly occurs in patients with a past or current history of acute myeloid leukemia (AML), myeloproliferative neoplasm, or myelodysplastic syndrome. However, in rare cases (as in the present case), myeloid sarcoma may develop as a solitary lesion without associated leukemia [1,2] at any age and in any organ, its clinical manifestations are diverse [3]. Although approximately 10% of myeloid sarcomas occur in the gastrointestinal tract, stomach involvement remains exceedingly rare [4].…”

“…The endoscopic features of gastric myeloid sarcoma range from near-normal mucosa to elevated ulcers or mass lesions [5]. Al-though the diagnosis of myeloid sarcoma in patients with AML is usually straightforward, the diagnosis of an isolated myeloid sarcoma (nonleukemic) can be challenging [1][2][3]. Histopathology and immunohistochemistry findings are key in establishing the diagnosis.…”

“…Myeloid sarcoma should be considered in the differential diagnosis of an atypical cellular infiltrate regardless of the site [2]. Extensive immunohistochemical panels must be used; otherwise, differentiating these lesions from tumors such as lymphoma may be extremely difficult [2][3][4]. The prognosis of myeloid sarcoma is generally poor.…”

“…The prognosis of myeloid sarcoma is generally poor. Without treatment, most patients succumb to the disease within a short space of time after diagnosis [2,3]. Systemic chemotherapy remains the mainstay of treatment even for isolated myeloid sarcomas because most patients progress to AML [2,3].…”

“…Without treatment, most patients succumb to the disease within a short space of time after diagnosis [2,3]. Systemic chemotherapy remains the mainstay of treatment even for isolated myeloid sarcomas because most patients progress to AML [2,3]. Radiotherapy and/or surgery are usually reserved to treat residual lesions or reduce the mass effect of a symptomatic myeloid sarcoma [2,3].…”