Myopathy due to HMGCR antibodies in adult mimicking muscular dystrophy associated with cancer and statin exposure – narrative review of the literature – case report

Figures & data

Figure 1 Axial muscle MRI of thighs and legs and muscle biopsy findings (gastrocnemius).

Notes: (A–H) MRI of the thighs: axial T1-weighted images (A and B) show mild fatty degeneration of right and left semimembranosus (arrow). Axial fat-suppressed T2-weighted images (C and D) reveal edema of the right semimembranosus and very mild edema of left semimembranosus (arrow) and long head of biceps femoris (arrow head). MRI of the legs: axial T1-weighted images (E and F) show fatty degeneration of medial head of gastrocnemius (arrow) and soleus bilaterally (arrowhead). Axial fat-suppressed T2-weighted images (G and H) reveal mild edema of the medial head of gastrocnemius (arrow) and soleus(arrow head) bilaterally. (I–N) Histological findings: (I) H&E stain: variation in fiber size, connective tissue proliferation and necrosis. (J) Gomori trichrome: connective tissue proliferation. (K–N) Positive immunostaining for MHC class I CD4, CD8 and CD68, respectively. (I–N) 10×; scale bar: 1 μm.
Abbreviations: MHC, major histocompatibility complex; MRI, magnetic resonance imaging.

Figure 2 Axial muscle MRI of thighs and legs.

Notes: Thighs (A–D): diffuse edema of the right semimembranosus and tenuous edema of the left semitendinosus and femoral biceps. Legs (E–H): diffuse edema and discreet fatty infiltration of the soleus muscle and the medial and lateral heads of both gastrocnemii.
Abbreviation: MRI, magnetic resonance imaging.

Table 1 Previous cases reported with anti-HMGCR myopathy simulating dystrophic-like pattern

Authors	n	Gender (M/F)	Initial presentation	Age of onset	Age of diagnosis	CK (first visit)
Mohassel et al,^Citation5 2017	1	M	Decrease in running	9 years	14 years	8,000
Tard et al,^Citation6 2017	1	F	Abnormal gait	5 years	19 years	7,576
Liang et al,^Citation7 2017	4	NO	Motor delay	10 months	NO	352–918
		NO	Asymptomatic high CK	6 years	NO	6,391
		NO	Difficulty in pedaling and climbing stairs	13 years	NO	7,183
		NO	Difficulty in climbing stairs	9 years	NO	9,570

Abbreviations: CK, creatine kinase; HMGCR, 3-hydroxy-3-methylglutaryl coenzyme A reductase; NO, not obtained.

MohasselPFoleyARDonkervoortSAnti-3-hydroxy-3-methylglutaryl-coenzyme a reductase necrotizing myopathy masquerading as a muscular dystrophy in a childMuscle Nerve20175661177118128066895

 PubMed Web of Science ®Google Scholar

TardCTiffreauVJailletteEAnti-HMGCR antibody–related necrotizing autoimmune myopathy mimicking muscular dystrophyNeuropediatrics201748647347628778101

 PubMed Web of Science ®Google Scholar

LiangWCUruhaASuzukiSPediatric necrotizing myopathy associated with anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase antibodiesRheumatology (Oxford)201756228729327818386

 PubMed Web of Science ®Google Scholar