Psammoma body and its precursors in papillary thyroid carcinoma: A study by fine‐needle aspiration cytology

Abstract

Psammoma bodies (PBs) form an important diagnostic criterion of papillary thyroid carcinoma (PTC), but their mechanism of formation is not clear. Following our observation in a case of PTC that laminated hyaline globules may be the precursor form of PBs, the present study was undertaken to find out their relation to PBs in PTC cases. Fifty-four cases of PTC and 14 follicular neoplasms, diagnosed by fine-needle aspiration (FNA) cytology, were studied by one of the investigators (DKD) to find out the PBs, irregular calcifications, hyaline globules, and other forms made of similar material. PBs along with irregular calcification were present in five PTC cases, PB alone was present in 1 case, and irregular calcification alone was present in 4 cases. Large hyaline globules (LHGs), small hyaline globules (SHGs), branching hyaline cylinders (BHCs), and irregular hyaline deposits (IHDs) were identified in 10, 14, 6, and 9 cases, respectively. One or more of these four forms were present altogether in 18 (33.3%) of PTC cases and none of the follicular neoplasms (P=0.0142). These forms were present in 80.0% of cases with PB/irregular calcifications as opposed to 22.7% in cases without them (P=0.0012). Our observations suggest that LHGs, SHGs, and BHCs are precursors of PBs and IHDs serve as a nidus for irregular calcification.

Relationship between patterns of calcification in thyroid nodules and histopathologic findings

“…Psammoma bodies are typically seen in papillary thyroid carcinoma. But, ultrasonographic microcalcification is not completely explain psammoma bodies, because there are several calcification types histologically [13,14]. Wang et al [4] reported microcalcification was present in 38.2% (26 of 68) of malignant nodules with calcification.…”

Morphometric characteristics of choroid plexus epithelial cells in cases with significantly different psammoma bodies' presence

“…Many hypotheses suggest that psammoma bodies are formed inside fibrovascular cores of tumors papillae. Some authors consider that initial focus for psammoma bodies formation is single necrotic tumors cell (Johannessen and Sobrinho-Simoes, 1980), others that it is progressive infarction of the tumors papillae, because of delicate vessels within the fibrous core undergo thrombosis or damage as a result of minimal trauma (Das et al, 2004;Pillai et al, 2007). These theories are in agreement with our assumption that choroid plexus psammoma bodies formation starts in its villi.…”

“…However, we did not find in the present literature data about their occurrence in stromal component of any other organ during the aging process. They were observed, the most frequently, in stroma of pathologic formations, especially tumors (Das et al, 2004;Fausett et al, 2002;Johannessen and Sobrinho-Simoes, 1980;Kawahara et al, 2001;Kubota et al, 1984Kubota et al, , 1985Kubota et al, , 1986Nakayama et al, 1997). Klinck and Winship (1959), in their article, cited Wegelin's opinion that choroid plexus psammoma bodies and in some kind of tumors represent the same phenomenon.…”

Diagnosis of Papillary Thyroid Carcinoma in Fine Needle Aspiration Smears

“…Although the presence of psammoma bodies is diagnostic of PTC, they are present in FNA smears of 11.1-35.0% of PTC cases only. 22 In view of the limitations of individual cytomorphologic features, the contribution of a combination of these features in decision making needs to be examined. According to Punthakee et al, 23 in choosing the most appropriate management of a finding suspicious for PTC on FNA biopsy, the surgeon must be aware of the diagnostic importance of certain cytopathologic features, and the presence of a combination of features may allow a more confident surgical approach.…”