[The 478 th case: multiple myalgia with intramuscular nodules].

Area of Science:

• Oncology
• Pathology
• Radiology

Background:

• A 28-year-old male presented with myalgia and intramuscular nodules.
• Initial symptoms included dysphagia, fever, and weight loss.

Observation:

• Magnetic resonance imaging (MRI) and initial biopsy suggested nodular fasciitis.
• Elevated inflammatory markers and positive urine occult blood were noted.
• Abdominal ultrasound revealed left hydronephrosis.

Findings:

• A second biopsy of intramuscular nodules revealed poorly differentiated metastatic adenocarcinoma.
• Positron emission tomography-computed tomography (PET-CT) confirmed advanced gastric adenocarcinoma.
• Metastases were extensive, involving the esophagus, lymph nodes, muscles, ureter, and bone.

Implications:

• This case underscores the diagnostic challenge of metastatic cancer mimicking benign conditions like nodular fasciitis.
• It emphasizes the need for comprehensive staging and diagnostic workup in patients with unexplained symptoms and suspicious findings.
• The rapid disease progression and poor outcome highlight the aggressive nature of advanced gastric adenocarcinoma.