Phosphoglyceride crystal deposition disease requiring differential diagnosis from malignant tumors and confirmed by Raman spectroscopy: A case report

Figure 1 Contrast-enhanced computed tomography shows a 50 mm × 40 mm × 48 mm mass protruding from below the serosa at the greater curvature of the upper stomach. A: Contrast enhancement is observed in the arterial phase; B and H: A 50 mm × 40 mm × 48 mm mass protrudes outward from the greater curvature of the upper stomach; C and I: A nodule about 7 mm in size is found near the accessory spleen; D and J: Three masses protruding from the abdominal wall into the peritoneal cavity are also observed. The most cranial abdominal wall mass measures 28 mm × 16 mm × 18 mm and has irregular margins; E and K: The middle abdominal wall mass measures 55 mm × 42 mm × 36 mm and has irregular margins; F and L: The most caudal abdominal wall mass measures 55 mm × 44 mm × 55 mm and has irregular margins. All of these masses show internal calcification and contrast enhancement; G: Plain computed tomography.

Figure 2 ¹⁸F-fluorodeoxyglucose positron emission tomography. A and B: Scan image; C: A 50-mm mass with high fluorodeoxyglucose (FDG) uptake [maximum standardized uptake value (SUVmax) 34.19] is seen protruding toward the serosa at the greater curvature of the stomach. A 50-mm intraperitoneal mass compressing the stomach is observed at the site of the previous splenectomy; D: A nodule about 7 mm in size with high FDG uptake (SUVmax 11.29) is observed near the accessory spleen; E: The most cranial abdominal wall mass shows high FDG uptake (SUVmax: 37.71); F: The middle abdominal wall mass shows high FDG uptake (SUVmax: 37.71); G: The most caudal abdominal wall mass shows high FDG uptake (SUVmax: 37.71).

Figure 3 An intraoperative photograph shows an incision of approximately 5 cm made at the scar from the previous pararectal incision. Dissection of the tissue reveals a hard, elastic, whitish mass, from which two 2-cm portions are excised.

Figure 4 Histopathological findings of the surgical specimens. A and B: Histopathological findings show a well-demarcated nodule of needle-like crystals surrounded by a fibrous capsule, with histiocytes and multinucleated giant cells (hematoxylin and eosin stain; A: × 200; B: × 400); C: Histiocytes are immunohistochemically positive for CD68 (× 200).

Figure 5 Raman spectra of the target and control areas. The following peaks are seen in the target area: 1000-1300 cm^-1, P-O and P=O bonds of phosphate (partially overlapping with the alkyl group signal); 1400-12800 cm^-1, C-H bonds of saturated hydrocarbon groups; 1600-13800 cm^-1, C=C bonds of unsaturated hydrocarbons; 1700 cm^-1, C=O bonds of esters.