A Rare Case of Systemic AL Amyloidosis with Muscle Involvement: A Misleading Diagnosis

Muscle involvement in AL amyloidosis is a rare condition, and the diagnosis of amyloid myopathy is often delayed and underdiagnosed. Amyloid myopathy may be the initial manifestation and may precede the diagnosis of systemic AL amyloidosis. Here, we report the case of a 73-year-old man who was referred to our center for a monoclonal gammopathy of undetermined significance (MGUS) diagnosed since 1999. He reported a progressive weakness of proximal muscles of the legs with onset six months previously. Muscle biopsy showed mild histopathology featuring alterations of nonspecific type with a mixed myopathic and neurogenic involvement, and the diagnostic turning point was the demonstration of characteristic green birefringence under cross-polarized light following Congo red staining of perimysial vessels. Transmission electron microscopy (TEM) con firmed amyloid fibrils around perimysial vessels associated with collagen fibrils. A stepwise approach to diagnosis and staging of this disorder is critical and involves confirmation of amyloid deposition, identification of the fibril type, assessment of underlying amyloidogenic disorder, and evaluation of the extent and severity of amyloidotic organ involvement

Dedalo: Phase II Study of Daratumumab Plus Pomalidomide and Dexamethasone (DPd) in Patients with Relapsed/Refractory Multiple Myeloma and 17p Deletion

Deletion of the short arm of chromosome 17 (del(17p)) is a well-established high-risk feature in multiple myeloma (MM) and is included in current disease staging criteria. Treatment of del(17p) MM is a major challenge, since the disease is characterized by rapid development of chemoresistance and short survival. The size of the del(17p) clone correlates with prognosis, and the threshold value of 55% to 60% has the worst prognosis. Approximately a third of patients (pts) have a concomitant TP53 mutation, with a complete abolition of the protein function. TP53 biallelic inactivation is defined as double-hit myelom