Unusual Cytological Finding in Body fluid in an Elderly Female. Psammomatous Calcification.

INTRODUCTION

The word psammoma is derived from psammos [“sand”] oma[“tumor”]. Psammoma bodies (PBs) are concentrically lamellated calci?c spherules that occasionally appear cracked. PBs usually are associated with various benign conditions such as the use of intrauterine devices, oral contraceptives, endosalpingiosis, endometriosis, endometritis, and others as well as with papillary neoplasms of various organs.[1] PBs rst was described by Virchow in association with a benign meningeal tumor. The presence of PBs in ne needle aspiration samples of certain neoplasms, such as papillary thyroid carcinoma, ovarian papillary serous carcinoma, meningioma, and others, is well established and is considered to be diagnostically signi?cant. In addition, an association between PBs on cervicovaginal smears and the presence of various gynecologic tract lesions (endocervical, endometrial, and ovarian) has been well documented.[12]

CASE PRESENTATION

A 56-year-old female presented to the department of surgical oncology with complaints of abdominal distention and dull aching pain in the abdomen for the past 15 days. On clinical examination, ascites was suspected hence a contrast-enhanced computed tomography (CECT) scan of thorax and abdomen was advised and ascitic fluid was also sent for cytological examination. Computed tomography (CT) scan abdomen revealed bilaterally enlarged ovaries with right ovary measuring 5 × 3 × 4.5 cm and left ovary measuring 4.1 × 3.8 × 2.6 cm with solid heterogeneous enhancement. Nodular enhancing thickness was also noted in the omentum extending into the gall bladder fossa. Moderate ascites with few calcifications were noted in the parietal peritoneum.

Cytological examination of ascitic fluid revealed atypical cells in cohesive clusters, groups, and papillaroid pattern. Few of the papillaroid fragments showed laminated dystrophic calcification. Atypical cells were round to oval in shape which exhibited mild to moderate anisonucleosis with vesicular to hyperchromatic nuclei, conspicuous nucleoli, and a moderate amount of vacuolated cytoplasm. Mitotic activity was also noted. The background comprised of reactive mesothelial cells and blood [Figure 1a and b]. Cell block preparation also shows psammomatous calcification. Immunohistochemistry was done on cell block keeping ovarian primary as suspected on CT. Tumor came positive for PAX8 immunomarker consistent with female genital origin of tumor other markers like calretinin, employed for mesothelial cell came negative in that papillaroid clusters that came positive to PAX8 [Figure 2a and b]. Hence, metastatic adenocarcinoma was given favoring ovarian primary.

Figure 1

(a and b) Papillaroid fragments exhibiting concentric lamellation (a-Pap stain, 400x, b-Giemsa stain 400X)

Figure 2

(a) Psammoma body adjacent to tumor (cell block, H and E stain, 400X). (b) PAX8 nuclear positivity of tumor (IHC, 100X)

DIFFERENTIAL DIAGNOSIS

Psammoma bodies can be seen in body cavity fluid (BCFs) in various conditions which include both benign and malignant. Common benign conditions showing presence of psammoma bodies especially in peritoneal fluid include ovarian cystadenoma/cystadenofibroma, Papillary mesothelial, hyperplasia, endosalpingiosis, endometriosis, malignant conditions with presence of psammoma bodies in BCF include papillary serous ovarian carcinoma, endometrioid ovarian carcinoma, and mesothelioma.[12]

DISCUSSION

Serous carcinoma usually presents as cellular specimens in cytology containing single cells or poorly cohesive irregular cell clusters with large, pleomorphic nuclei, and prominent nucleoli. Peritoneal washings involved by endometrioid carcinomas display loose, three-dimensional clusters of cells with abundant delicate cytoplasm and eccentric, pleomorphic nuclei, coarse chromatin pattern, and prominent nucleoli. Clear cell carcinoma also demonstrates similar cytologic features.[3] The main differential diagnosis of adenocarcinoma in a peritoneal washing is reactive mesothelial cells. Presentation of reactive mesothelial cells is usually seen as clusters of epithelioid cells with occasional cell ball or papillary cluster formation. The reactive mesothelial cells show cellular enlargement, dense cytoplasm, and large nuclei with increased nuclear to cytoplasmic ratio. Occasionally, the cells might be vacuolated or contain prominent nucleoli. The presence of cellular ''windows'' might help to identify the cells as mesothelial.[4] Cases of endosalpingiosis display organized, tight clusters with occasional nonbranching papillary formation. The cells are uniform with scant basophilic cytoplasm. The nuclei have smooth nuclear membranes, a fine chromatin pattern, and small nucleoli. It is important to remember that psammoma bodies might be present in cases of endosalpingiosis. Large papillary clusters with architectural disorganization are used to distinguish endosalpingiosis from the serous borderline tumor.[5] Endometriosis is another mimicker. It is characterized by the presence of round to oval cells arranged in three dimensional clusters, tubular structures, and sheets. The nuclei are round or bean shaped with fine chromatin and rare nucleoli. The cytoplasm is scant and vacuolated. The presence of hemosiderin-laden macrophages is the most sensitive finding in endometriosis.[3] A panel of antibodies can be used to discriminate between gynecologic adenocarcinoma and reactive mesothelial cells. MOC-31 and Ber-EP4 appear to be the most effective markers to distinguish adenocarcinoma from reactive mesothelial cells.[4] A combination of Pan-CK, Calretinin, PAX- 8, WT 1 can be used to distinguish between ovarian primary and mesothelial cells.

CONCLUSION

Psammomatous calcification in ascitic fluid is a very infrequent finding noted in cytopathology. Once it is detected it can give clues about underlying pathology. Concomitant clinicoradiological correlation may lead to the diagnosis.

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Conflicts of interest

There are no conflicts of interest.