Bone marrow metastasis of rhabdomyosarcoma mimicking acute leukemia: a case report and review of the literature

Mechanism and clinical progression of solid tumors bone marrow metastasis

The rich blood supply of the bone marrow provides favorable conditions for tumor cell proliferation and growth. In the disease's early stages, circulating tumor cells can escape to the bone marrow and form imperceptible micro metastases. These tumor cells may be reactivated to regain the ability to grow aggressively and eventually develop into visible metastases. Symptomatic bone marrow metastases with abnormal hematopoiesis solid tumor metastases are rare and have poor prognoses. Treatment options are carefully chosen because of the suppression of bone marrow function. In this review, we summarized the mechanisms involved in developing bone marrow metastases from tumor cells and the clinical features, treatment options, and prognosis of patients with symptomatic bone marrow metastases from different solid tumors reported in the literature.

Metastatic Alveolar Rhabdomyosarcoma with Extensive Bone Marrow Replacement in an Older Adult

Rhabdomyosarcoma is extremely rare in adults. Metastatic rhabdomyosarcoma can resemble other malignancies, which can delay diagnosis and prompt treatment. This case illustrates an example of metastatic alveolar rhabdomyosarcoma with concurrent bone marrow infiltration. A 67-year-old woman presented with epistaxis and diffuse bone pain. She developed progressive thrombocytopenia requiring platelet transfusions. The patient was initially thought to have leukemia. She was found to have a large sinonasal mass with extensive metastatic disease and bone marrow infiltration. The patient was ultimately diagnosed with metastatic alveolar rhabdomyosarcoma. She was started on chemotherapy with vincristine, actinomycin, and cyclophosphamide. Unfortunately, she died prior to discharge home. Alveolar rhabdomyosarcoma can resemble a primary bone marrow malignancy when it infiltrates the bone marrow. Further investigation is needed to clarify its clinical behavior and expedite diagnosis and treatment.

Alveolar rhabdomyosarcoma of urinary bladder presenting as acute leukemia: A diagnostic trap

Rhabdomyosarcoma (RMS) masquerading as acute leukemia (AL) is very rare. We report a case which presented as acute leukemia subsequently diagnosed to be Alveolar RMS of Urinary Bladder. Although cases of RMS with leukemic presentation have been reported, to our knowledge this is the first case of Alveolar RMS of Urinary Bladder with leukemic picture at initial presentation. We would like to emphasize that this critical error can have serious consequences on the treatment and outcome of these patients.

Genomic analysis of metastatic rhabdomyosarcoma masquerading as acute leukemia

Blast appearing cells in the peripheral blood and bone marrow may occasionally arise from non-hematopoietic tissues. We present a 58 year old female who presented at our emergency room with symptomatic pancytopenia. Several months earlier she was diagnosed and treated for rhabdomyosracoma of the nasopharynx and entered remission. When we examined the bone-marrow aspirate we estimated the number of blasts at 25 %. Based on this evaluation, a provisional diagnosis of acute leukemia was made. However, immunohistochemistry and flow cytometry analysis revealed that the cells presumed to be blasts were in fact rhabdomyosarcoma cells masquerading as leukemia. The mutational landscapes of the primary tumor and the bone marrow metastasis had similar yet distinct profiles. Annotation analysis suggested that the primary and metastatic tumors use alternate mutations to activate the RAS/AKT signaling pathways. In this case, looking beyond the mutational profiling revealed an additional layer of similarity between both the original and metastatic samples, exposing a common and possibly targetable pathway. Application of annotation tools in clinical practice could enable extraction of valuable information from somatic mutational gene panels.

Rhabdomyosarcoma debut masquerading as acute lymphoblastic leukemia: A case report and review of the literature

Bone marrow infiltration by alveolar rhabdomyosarcoma is uncommon, some cases can mimicry acute leukemia at presentation and mislead the diagnosis. The integration of diagnostics tests and techniques in uncommon malignancies is important to suspect and reach the diagnosis and avoid delay on treatment. We report a case of alveolar rhabdomyosarcoma bone marrow infiltration associated with hemophagocytosis and cell cannibalism, mimicking acute leukemia at presentation.

Nasal embryonal rhabdomyosarcoma with bone marrow metastasis simulating acute leukemia: A case report and review of the literature

We present a case of a nasal rhabdomyosarcoma (RMS) in a 27-year-old male with epistaxis and nasal obstruction due to a mass, which was subjected to prophylactic tumor embolization. However, histopathological study on the nasal biopsy was impossible due to necrotic changes. As blast cells were present in peripheral blood samples, a bone marrow biopsy was recommended in order to reach a definitive diagnosis. The possibility of an RMS in cases of bone marrow infiltration by a diffuse tumor constituted by small, round, blast-like cells mimicking acute leukemia should be assessed. Immunohistochemical staining in bone marrow biopsy and flow cytometry in aspirate samples may help to establish the diagnosis (CD45 negativity and CD56 positivity) and cytogenetic studies can be useful in identifying a RMS subtype. When clinically possible, it is desirable to await the results of the tumor immunophenotype and those of the primary mass or bone marrow biopsy to avoid possible errors of diagnosis and treatment.

Acute lymphoblastic leukemia arising after treatment of Ewing sarcoma was misdiagnosed as bone marrow metastasis of Ewing sarcoma: A case report

RATIONALE

Both acute lymphoblastic leukemia (ALL) and Ewing sarcoma (ES) are small round cell tumors, and it is difficult to differential diagnose them because of overlapping clinical, radiographic, histologic, and immunophenotypic features.

PATIENT'S CONCERNS

A 5-year-old boy was admitted to our hospital because of pains in his left leg without obvious inducement and lameness worsening with walking over a two 2-month period.

DIAGNOSES

Based on the comprehensive analysis of radiography, magnetic resonance imaging (MRI), pathology biopsy and immunohistochemistry, the lesion was confirmed to be ES.

INTERVENTIONS

The patient received neoadjuvant chemotherapy with 2 cycles of VAC (vincristine 1 mg/m, adriamycin 50 mg/m, cyclophosphamide 800 mg/m) and 2 cycles of IE (ifosfamide 1.2 g/m, etoposide 70 mg/m, mesna 1.2 g/m) regimens.

OUTCOMES

After 16 months, the results of routine blood tests showed reduced hemoglobin levels and decreased platelet counts. In addition, blast-like cells were found in a peripheral blood smear. All of the results suggested that the patient should undergo bone marrow aspiration and biopsy, which showed blast-like cells similar to that observed in cases of ES. Thus, a diagnosis of bone marrow metastasis of ES was established. However, when combined with immunohistochemistry data and medical history, the patient was eventually diagnosed as ALL arising after treatment of ES.

LESSONS

When there was an abnormality in peripheral blood, it was easily misdiagnosed as bone marrow metastasis of ES after ES patient received neoadjuvant chemotherapy. We should jointly analyze bone marrow aspiration smear, bone marrow biopsy, immunohistochemistry, analysis of the medical history, even cytogenetic and molecular analysis for differential diagnosis.