• cutaneous lymphoma
• extramedullary myeloid proliferation
• leukemia cutis
• myelodysplasia cutis
• myeloid sarcoma
• small blue round cell tumor

• Humans
• Diagnosis, Differential
• Algorithms
• Skin Neoplasms/diagnosis
• Skin Neoplasms/pathology
• Skin/pathology
• Leukemic Infiltration/diagnosis
• Leukemic Infiltration/pathology
• Leukemia/diagnosis
• Leukemia/pathology

• Neuroimaging
• Neurooncology

• Male
• Humans
• Sarcoma, Myeloid/diagnosis
• Neoplasm Recurrence, Local
• Meningeal Neoplasms/diagnostic imaging
• Meningeal Neoplasms/therapy
• Blindness
• Granulocyte Precursor Cells

• Acute myeloid leukemia
• Extra-axial
• Myeloid sarcoma
• Raised ICP

• Male
• Child
• Humans
• Sarcoma, Myeloid/diagnostic imaging
• Sarcoma, Myeloid/surgery
• Leukemia, Myeloid, Acute/diagnostic imaging
• Leukemia, Myeloid, Acute/pathology
• Sarcoma, Ewing
• Meningeal Neoplasms/diagnosis
• Brain Neoplasms/diagnostic imaging
• Brain Neoplasms/surgery

Myeloid sarcoma (MS) is relatively rare, occurring mainly in the skin and lymph nodes, and MS invasion of the ulnar nerve is particularly unusual. The main aim of this article is to present a case of MS invading the brachial plexus, causing ulnar nerve entrapment syndrome, and to further clinical understanding of the possibility of MS invasion of peripheral nerves.

We present the case of a 46-year-old man with a 13-year history of well-treated acute nonlymphocytic leukaemia who was admitted to the hospital after presenting with numbness and pain in his left little finger. The initial diagnosis was considered a simple case of nerve entrapment disease, with magnetic resonance imaging showing slightly abnormal left brachial plexus nerve alignment with local thickening, entrapment, and high signal on compression lipid images. Due to the severity of the ulnar nerve compression, we surgically investigated and cleared the entrapment and nerve tissue hyperplasia; however, subsequent pathological biopsy results revealed evidence of MS. The patient had significant relief from his neurological symptoms, with no postoperative complications, and was referred to the haemato-oncology department for further consultation about the primary disease. This is the first report of safe treatment of ulnar nerve entrapment from MS. It is intended to inform hand surgeons that nerve entrapment may be associated with extramedullary MS, as a rare presenting feature of the disease.

MS invasion of the brachial plexus and surrounding tissues of the upper arm, resulting in ulnar nerve entrapment and degeneration with significant neurological pain and numbness in the little finger, is uncommon. Surgical treatment significantly relieved the patient’s nerve entrapment symptoms and prevented further neurological impairment. This case is reported to highlight the rare presenting features of MS.

• Myeloid sarcoma
• Ulnar nerve entrapment syndrome
• Acute nonlymphocytic leukaemia
• Sarcoma
• Upper limb surgery
• Case report

Myeloid sarcoma (MS), or chloroma, is a rare extramedullary malignant tumor that consists of undifferentiated granulocytic cells, and it is most commonly associated with acute myeloid leukemia (AML). Intracranial MS accounts for 0.4% of MS cases, and involvement of the skull base and visual dysfunction is rarely reported. However, the optimal treatment and response to treatment of skull base MS in the presence of visual symptoms is unknown.

A 30-year-old male with a history of AML presented with rapidly progressive vision loss and a sellar and parasellar mass with bilateral cavernous sinus and optic nerve encasement. The patient underwent endoscopic endonasal transsphenoidal biopsy revealing intracranial MS. He was treated postoperatively with high-dose intravenous and intrathecal cytarabine and had complete restoration of his vision by postoperative day 11. A systematic review of the literature identified six cases of skull base MS, five of whom presenting with visual symptoms. All patients underwent systemic chemotherapy with cytarabine and/or cyclophosphamide, with infrequent use of intrathecal chemotherapy or radiation. Those with reported visual outcomes were diagnosed 4 months or longer after symptom onset and demonstrated no visual improvement with treatment.

Skull base MS is a rare disease entity with a high prevalence of visual dysfunction. Our patient’s complete disappearance of intracranial disease and resolution of visual symptoms with systemic and intrathecal chemotherapy highlight the importance of timely diagnosis and appropriate treatment without a need for direct surgical decompression.

• Acute myeloid leukemia
• Chloroma
• Myeloid sarcoma
• Parasellar
• Skull base

Myeloid sarcoma (MS)/granulocytic sarcoma/myeloblastoma/chloroma is a rare extramedullary proliferation of blast cells of one or more myeloid lineages along with the destruction of the normal architecture of adjacent tissue. Isolated MS is a rare entity with an incidence of 0.7 out of 1 million children and 2 out of 1 million adults. Varied clinical presentation, the rarity of the diagnosis, inadequate immunophenotyping, and lack of available literature makes the disease difficult to manage. Here, we report a case of MS in a 44-year-old male with an initial presentation of testicular mass without bone marrow involvement, causing diagnostic challenges. In this case report, we discuss the pathogenesis, diagnostic challenges, and therapeutic options of MS.

• acute myeloid sarcoma
• aml
• cytarabine
• leptomeninges
• testicular mass

• Myeloid sarcoma
• acute myeloid leukemia
• cytogenetics
• extramedullary
• medullary
• molecular