Researchers presented the case study of a patient with skeletal osteosclerotic lesions secondary to aggressive systemic mastocytosis in Cureus.

A 68-year-old woman presented with a 3-week history of right upper quadrant abdominal pain. The pain was worse after eating and relieved with the application of a heating pad. In addition, she complained of fatigue and loss of appetite. She denied vomiting, changes in her bowel habits, or weight loss. 

Laboratory tests revealed normocytic anemia (hemoglobin: 11.6 mg/dL), an elevated erythrocyte sedimentation rate (96 mm/h), and elevated alkaline phosphatase levels (310 IU/L). A rheumatologic workup was unremarkable. The patient tested negative for hepatitis. Serum and urine electrophoresis were negative for multiple myeloma. Tumor markers (cancer antigen 15-3, cancer antigen 19-9, and alpha-fetoprotein) were negative; only carcinoembryonic antigen was positive (53.7). 

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An abdominal ultrasound revealed an overdistended gallbladder that was suggestive of gallbladder sludge as opposed to a polyp. The common bile duct was dilated. The patient’s physicians also detected an echogenic liver lesion likely to be a hemangioma. 

A magnetic resonance cholangiopancreatography revealed normal intrahepatic bile ducts and no signs of choledocholithiasis. A computed tomography scan of the abdomen and pelvis revealed numerous scattered bony sclerotic lesions suggestive of metastatic disease. 

In addition, the patient’s physicians discovered calcification densities adjacent to the gallbladder wall up to 1.2 cm in size, which were suggestive of a gallbladder polyp (instead of sludge). The physicians found a number of abdominal and retroperitoneal subcentimeter lymph nodes; nevertheless, no pathologically enlarged lymph nodes were detected. 

“A nuclear medicine bone scan of the whole body was obtained, showing multiple areas of uptake involving the axial skeleton and proximal femurs, suspicious for metastatic disease,” the authors of the study wrote.

Extensive studies suggested that the patient had metastatic carcinoma of unknown primary origin. A bone marrow biopsy finally revealed morphological findings consistent with systemic mastocytosis, which was confirmed by the detection of a C-kit mutation positive for the D816V variant. In addition, serum tryptase levels were elevated (174 ng/mL). 

The patient was started on midostaurin, and a repeat bone scan 6 months later demonstrated significant interval improvement. Her tryptase levels also decreased. 

“This case represents a prime example of where keeping a broad differential for diagnostically challenging cases is crucial to arrive at an accurate diagnosis of [systemic mastocytosis] and a tailored treatment plan,” the authors of the study concluded. 

Reference

Ghorpade R, Tissavirasingham F, Vennepureddy A. A rare case of aggressive systemic mastocytosis with skeletal osteosclerotic lesions on presentation: a diagnostic conundrum. Cureus. Published online December 2, 2022. doi:10.7759/cureus.32135