Myeloid sarcoma with megakaryoblastic differentiation mimicking a sellar tumor

Myeloid sarcoma of the skull base: A case report and systematic literature review

Background:

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.

Case Description:

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.

Conclusion:

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.

Clinicopathological analysis of myeloid sarcoma with megakaryocytic differentiation

Myeloid sarcoma (MS) is defined as a tumour mass consisting of myeloid blasts that occurs at an anatomical site other than bone marrow. MS with megakaryocytic differentiation (MSmgk) is extremely rare and its clinicopathological features have not been well described. We reviewed 11 cases in 11 patients of extramedullary mass-forming malignant tumours composed of immature non-lymphoid haematopoietic cells expressing CD41 with or without concurrent bone marrow lesions. The patients consisted of seven men and four women (1.75:1 male-to-female ratio). The mean and median ages at diagnosis were 50 and 62 years, respectively, ranging from 2 to 78 years. Extramedullary mass lesions were solitary in three cases (27%) and multiple in eight cases (73%). Tumour locations were lymph nodes (6 cases), subcutaneous tissue (3 cases), intramuscular (1 case), and bone (1 case). Seven of the 11 patients (64%) had a history of myelodysplastic syndrome (MDS) or myeloproliferative neoplasm (MPN). Three patients (27%) developed MS during remissions of acute myelogenous leukaemia, and one patient had a recurrence of MS at other sites. Follow-up data were available for four cases. Tumour cells were positive for CD41, CD33, CD34, MPO, and CD68 in 11 (100%), three (27%), seven (64%), four (36%), and seven (64%) cases, respectively. Cytogenetic analysis was successfully performed in two cases. Complex but inconsistent abnormalities were evident. When compared with cases of MS without megakaryocytic differentiation, the survival of MSmgk was significantly shorter (p=0.0033). Compared to MS without megakaryocytic differentiation, MSmgk is more likely to follow MDS/MPN, to involve multiple sites, and to be associated with poorer outcomes. More detailed studies, including genomic or gene expression analyses, could confirm the characteristics of MSmgk.

Sarcomas of the sellar region: a systematic review

PURPOSE AND METHODS

Sarcomas of the sellar region are uncommon and unexpected tumors. Here, we review the cases reported in literature via a systematic search.

RESULTS

Ninety-four patients, 58.5% male with mean age of 39.2 ± 17.2 years were included. Fifty-seven (62%) had soft tissue sarcomas (STS) and 35 (38%) bone sarcomas (BS). Sarcoma was a primary tumor in 66%, developed after radiotherapy in 31.9% and 7.4% were metastatic. Median time between radiotherapy and sarcoma development was 10.5 (11) years. Main presentation symptoms were visual disorders (87.9%), headache (61.5%) and III cranial nerve palsy (24.1%). After surgery, sarcoma persisted or recurred in 82.3% and overall mortality reported was 44.6% with 6.5 (14) months of median survival. Tumor appeared earlier in BS compared to STS (34.4 ± 15.1 vs. 42.6 ± 17.6 years), p = 0.034 and complete tumor resection was achieved more often (41.3% vs. 4.4%), p =  < 0.001. Condrosarcoma and rhabdomyosarcoma were more frequent subtypes among primary tumors while fibrosarcoma was among post-radiation sarcomas. Tumor size was larger in radiation associated sarcomas (mean maximum diameter 46.3 ± 9.3 vs. 29.1 ± 8.0 mm, p = 0.004) and persistency/recurrence was similar in both groups (70.1 vs. 73.3%, p = 0.259).

CONCLUSION

Sarcomas appear as mass effect symptoms in the middle aged population, mainly as primary tumors, but one third is associated with radiotherapy. Surgery is commonly not curative, mortality rate is high and death ensues shortly after diagnosis.

Treatment Outcomes of Intracranial Myeloid Sarcomas: A Meta-Analysis

OBJECTIVE

Intracranial myeloid sarcomas (IMS) are rare central nervous system manifestations of malignant hematopoietic neoplasms of myeloid origin such as acute myeloid leukemia and chronic myeloid leukemia. Reported cases in the literature are limited to primarily case reports. We present a systematic review of this rare central nervous system tumor, characterizing the clinical presentation, tumor location, histopathology, and available treatment modalities. We correlate these variables with mortality, recurrence, and complications to suggest optimal management strategies for IMS.

METHODS

A systematic literature search was performed across Ovid MEDLINE, Scopus, and Embase using 14 search terms in accordance to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. This systematic review examines variables such as patient age, tumor location, size, presenting symptoms, treatment modality, extent of resection, and mortality. We performed descriptive analyses to identify bivariate associations between patient characteristics, treatment, and outcomes.

RESULTS

The mean age at diagnosis was 34.8 years, and the most common etiology was acute myeloid leukemia (68.8%). The most common presenting symptoms were headache (45.5%), vision complaints (27.3%), and weakness/motor symptoms (21.2%). IMS were most commonly located in the temporal lobe (10.1%), cerebellum (10.1%), or falcine/parasagittal (10.1%) region. Patients who received radiotherapy (P < 0.001) or chemotherapy (P < 0.001) had lower rates of mortality versus those who did not. Surgical treatment and extent of resection were not significantly associated with mortality (P > 0.05).

CONCLUSION

The use of adjuvant radiotherapy or chemotherapy for IMS significantly reduces mortality, confirming IMS as a cranial manifestation of a systemic disease. Although surgical treatment is indicated for histopathologic diagnosis and to relieve mass effect, the extent of resection does not predict overall survival.

Very late recurrence of B-cell acute lymphoblastic leukemia masquerading as a pituitary tumor

Involvement of the pituitary gland by leukemic infiltration is exceedingly rare. Here, we describe a very late recurrence of B-cell acute lymphoblastic leukemia masquerading as a pituitary tumor and review the literature for previously reported cases. Our female patient presented 13 years after completion of therapy for B-ALL with headache, amenorrhea, galactorrhea and a pituitary mass. Subsequent studies revealed recurrence of her leukemia, and the pituitary lesion resolved after induction chemotherapy. Our case highlights the importance of considering leukemic infiltrate in the differential diagnosis of pituitary mass, particularly in a patient with a history of hematologic malignancy, sparing unnecessary surgical intervention and informing endocrine evaluation. In addition, the case also highlights difficulties with characterizing this recurrence as a very late relapse or clonal evolution of the original leukemia.

Very Unusual Sellar/Suprasellar Region Masses: A Review

The cause of sellar region masses in large retrospective series is overwhelmingly pituitary adenomas (84.6%), followed by craniopharyngiomas (3.2%), cystic nonneoplastic lesions (2.8%), inflammatory lesions (1.1%), meningiomas (0.94%), metastases (0.6%), and chordomas (0.5%) (1). While other rare lesions were also identified (collectively 6.0%), single unusual entities in the above-cited series numbered <1-2 examples each out of the 4122 cases, underscoring their rarity. We searched our joint files for rare, often singular, sellar/suprasellar masses that we had encountered over the past several decades in our own specialty, tertiary care specialty pituitary center practices. Cases for this review were subjectively selected for their challenging clinical and/or histological features as well as teaching value based on the senior authors' (MBSL, BKD) collective experience with over 7000 examples. We excluded entities deemed to be already well-appreciated by neuropathologists such as mixed adenoma-gangliocytoma, posterior pituitary tumors, metastases, and hypophysitis. We identified examples that, in our judgment, were sufficiently unusual enough to warrant further reporting. Herein, we present 3 diffuse large cell B cell pituitary lymphomas confined to the sellar region with first presentation at that site, 2 sarcomas primary to sella in nonirradiated patients, and 1 case each of granulomatosis with polyangiitis and neurosarcoidosis with first presentations as a sellar/suprasellar mass. Other cases included 1 of chronic lymphocytic leukemia within a gonadotroph adenoma and 1 of ectopic nerve fascicles embedded within a somatotroph adenoma, neither of which impacted patient care. Our objective was to share these examples and review the relevant literature.

Myeloid Sarcoma with Megakaryoblastic Differentiation Arising in the Conjunctiva

An 87-year-old woman not known to have either a lymphoma or leukemia developed a left multinodular, fish-flesh superior epibulbar and forniceal mass. A biopsy disclosed a blastic tumor with scattered multinucleated immature megakaryoblasts. Immunophenotyping of bone marrow cells revealed strong positivity for CD7, CD31, CD43, CD45, CD61, and CD117; CD71, myeloperoxidase, and lysozyme were also positive in scattered cells. Forty percent of the neoplastic cells were Ki-67 positive. Cytogenetic studies indicated a trisomy 8 (associated with worse prognosis) and a t(12; 17) translocation. Desmin, smooth muscle actin, pancytokeratin, CAM 5.2, adipophilin, tryptase, S100, SOX10, MART1, and E-cadherin were negative, ruling out a nonhematopoietic tumor. The conjunctival lesion was diagnosed as a myeloid sarcoma with megakaryoblastic differentiation, a rare variant. It probably arose from a myelodysplastic syndrome. This is the first case of its type to develop in the conjunctiva.

Myeloid sarcoma with megakaryoblastic differentiation presenting as a breast mass

Myeloid sarcoma is an extramedullary tumor that consists of myeloblasts or immature myeloid cells. The neoplasm can occur in any part of the body, including the bone, periosteum, lymph nodes, skin, and soft tissue and they may occur de novo or in association with acute myeloid leukemia, myeloproliferative neoplasms and myelodysplastic syndromes. Most cases display a myelomonocytic or pure monoblastic morphology. Tumors with megakaryoblastic differentiation are extremely uncommon and may occur in association with transformation of a myeloproliferative disorder. Myeloid sarcoma presenting as a breast mass is very rare and diagnostically challenging. We report a case of myeloid sarcoma with megakaryoblastic differentiation in the breast of a patient with history of essential thrombocythemia. The mass was composed of undifferentiated pleomorphic malignant cells in trabecular cords and nests with many scattered giant malignant cells and brisk abnormal mitoses. On immunohistochemistry, the neoplastic cells were positive for CD61, CD31, CD34, Factor VIII and CD43 which confirmed the diagnosis. To our knowledge, this is the first report of myeloid sarcoma with megakaryoblastic morphology occurring in the breast. Here we discuss the clinicopathologic features of this rare entity and the challenges involved in making this difficult diagnosis.