Sustained remission and reversal of end-organ dysfunction in a patient with anaplastic myeloma

Anaplastic Multiple Myeloma: Case Series and Literature Review

Background: Anaplastic multiple myeloma (AMM) is a very rare but distinct subtype of multiple myeloma (MM) with an extremely poor prognosis. Due to its rarity, AMM lacks detailed descriptions and clear definitions. Moreover, there is no consensus on the treatment and evidence suggests that AMM responds poorly to several novel therapies. We conducted a literature review and retrospective case series to determine clinical characteristics, pathological features, and outcomes of AMM. Case Presentation: Published case reports and case series of AMM since 1983 were systematically extracted and reviewed. A total of 52 patients with AMM were reported in the PUBMED since 1983, including 26 males (50%) and 26 females (50%). The age ranged from 29 years old to 85 years old, with a mean age of 57.02 years old. Most of the patients presented with bone pain (23, 44.2%), fatigue (18, 34.6%), plasmacytoma (18, 34.6%) and weight loss (7, 13.5%). The median survival of the patients was 4 months. To investigate the outcomes of patients with AMM in the current era of treatment, a series of 14 patients with AMM diagnosed at our institute between December 2012 and July 2021was retrospectively analyzed. Our retrospective case series consisted of 12 males (85.7%) and 2 females (14.3%), with a mean age of 59 years old. Most of our AMM patients displayed bone lytic lesions as a common manifestation. The common cytogenetic abnormality was 1q amplification. All patients received standard combination chemotherapy consisting of proteasome inhibitors and/or immunomodulatory agents, and half of the patients underwent autologous hematopoietic stem cell transplantation. The median progression-free survival (PFS) and overall survival (OS) for our 14 AMM patients were 0.84 years and 1.52 years, respectively, which was significantly worse than the regular MM patients treated at our institute from 2003-2013 who had a PFS of 2.28 years and OS of 4.92 years. Conclusions: AMM is a very rare, morphologically distinct variant of MM. It has adverse cytogenetics and an aggressive course. It is often resistant to standard chemotherapy and presents with an extremely low survival rate.

Anaplastic multiple myeloma with MYC rearrangement

A 52-year-old man with rapidly progressive paraplegia was presented to us with paravertebral tumors. Laminectomy with tumor resection was performed, and pathological analysis of the tumor revealed compact proliferation of anaplastic plasmacytoid cells. G-band analysis of the tumor revealed a complex karyotype, including IgH/MYC translocation. The patient was diagnosed with anaplastic multiple myeloma (AMM) with MYC arrangement, and cytotoxic chemotherapy followed by autologous hematopoietic stem cell transplantation resulted in long-term disease-free remission. This is the first report describing a case of de novo AMM with MYC rearrangement, suggesting that conventional chemotherapy could be a treatment option for this formidable disease.

Plasma cell myeloma: role of histopathology, immunophenotyping, and genetic testing

Myeloma is a malignant neoplasm of plasma cells with complex pathogenesis. Diagnosis and risk stratification require the integration of histology, radiology, serology, and genetic data. Bone marrow biopsies are essential for myeloma diagnosis by providing material for histologic and cytologic assessment as well as immunophenotypic and genetic studies. Flow cytometry and genetic studies are, in particular, becoming increasingly important for diagnosis, risk stratification, and assessment of treatment response. Myeloma has traditionally been characterized by recurrent cytogenetic abnormalities that can be divided into two subtypes: hyperdiploid, characterized by trisomies, and non-hyperdiploid, characterized by translocations involving chromosome 14. These abnormalities are thought to be primary events, initiating a premalignant state, which progresses to myeloma through the acquisition of secondary mutations. The emergence of next-generation sequencing has led to the discovery of numerous mutations and gene fusions that comprise the heterogenous genomic landscape of myeloma. As the underlying pathogenesis of myeloma continues to be delineated, possible therapeutic targets have also emerged. Herein, we describe the importance of histology, immunophenotype, and mutational analysis in the assessment of myeloma.

Morphological Transformation of Myeloma Cells into Multilobated Plasma Cell Nuclei within 7 Days in a Case of Secondary Plasma Cell Leukemia That Finally Transformed as Anaplastic Myeloma

A 48-year-old man was diagnosed with multiple myeloma (IgG-k) and was treated with high-dose dexamethasone as an induction therapy followed by thalidomide-based regimens. Approximately 22 months after the initial diagnosis, the patient developed secondary plasma cell leukemia (PCL) with a white blood cell (WBC) count of 20.2 × 10⁹/L including 79.5% plasma cells. A G-banding chromosomal analysis in the bone marrow showed an t(11;14) abnormality of up to 5%, which was not detected at initial diagnosis. We immediately started bortezomib and dexamethasone therapy, but in just 7 days, the WBC count elevated to 48.5 × 10⁹/L, and approximately 95% of them were medium-sized atypical lymphoid cells with multilobated nuclei. Although we subsequently initiated alternative regimens, the patient's condition deteriorated, and he died 4 months after developing PCL. Approximately 2 months before his death, the diameter of myeloma cells in the bone marrow enlarged by approximately twofold, and pleomorphic nuclei were present, indicating an anaplastic myeloma transformation. Concurrently, a 100% increase of the t(11;14) clone frequency was observed in the G-banding-analyzed bone marrow cells. Morphological transformation of myeloma cells into multilobated plasma cell nuclei can be considered as the starting point of the sequential process leading to anaplastic myeloma.