Presacral chordoma diagnosed by transrectal fine-needle aspiration cytology.

Sir,

Chordoma is a rare malignant tumor of fetal notochord origin that can occur anywhere along the spinal axis but are most common at the top of the spine (the skull base) and at the bottom of spine (the sacrum).[1] An important prerequisite for optimal management of these tumors is a correct pre-operative diagnosis, and the role of preoperative fine-needle aspiration cytology (FNAC) in such cases is unquestionable.[2-4] On FNAC, chordoma shows varied but characteristic morphological features and a very few case reports on preoperative cytological diagnosis of chordoma are available.[24] The primary curative treatment of sacral chordoma includes complete surgical excision of the tumor with radiation therapy. Because these tumors have a tendency to recur, complete tumor removal is important and offers the best chance for cure.[5] We recently had a case of presacral mass, where transrectal FNAC along with radiological findings favored the diagnosis of chordoma.

A 42-year-old male presented with the complaints of pain in the lower back since 2 months with constipation and difficulty in passing urine since 3 weeks. Per-rectal examination revealed a soft mass in the presacral region pushing the posterior rectal wall anteriorly. Motor and sensory functions of both lower limbs and anal reflexes were normal. Computed tomography (CT) and magnetic resonance imaging scan showed a well-circumscribed soft tissue density mass lesion with altered signal intensity in the presacral region measuring 8×7.8×9.5 cm extending into the sacral spinal canal and displacing rectum and urinary bladder anteriorly with destruction of the sacrum and coccyx [Figure 1a]. FNAC of the presacral mass was done through transrectal route, yielding mucoid and jelly-like material. The smears were highly cellular and showed small groups and clusters of round epithelial cells with small round nuclei and scanty basophilic cytoplasm with few physalipherous cells. These physalipherous cells were large, round, had centrally placed small round vesicular nuclei with fine chromatin network, and abundant clear bubbly cytoplasm [Figure 1b]. The background showed abundant fibromyxoid material. A diagnosis of chordoma was made on the basis of physalipherous cells (soap bubble cells) in fibromyxoid background. The tumor was completely excised and sent for histopathological examination. Grossly, the tumor was soft and gelatinous with areas of hemorrhage. The histology revealed lobulated tumor composed of an admixture of large multivacuolated (physalipherous) cells and cuboidal cells, arranged in cords, sheets, and nests in a myxoid matrix [Figure 1c] confirming the FNAC diagnosis of chordoma. These tumor cells are generally immunoreactive for epithelial markers (cytokeratins, EMA) and S100 protein. Myxoid chondrosarcoma was considered in differential diagnosis; however, in view of clinical history, radiological findings with typical cytological finding of physalipherous cells in fibromyxoid background made us to arrive at the diagnosis of chordoma. Jin et al,[6] described the cytological diagnosis of chordoma without physalipherous cells. Gottlieb et al,[3] described the role of transrectal endoscopy- guided FNAC in chordoma diagnosis.Hence, transrectal FNAC of the presacral mass is the easiest and safest method for the preoperative diagnosis and to plan the further surgical management of chordoma.

Figure 1

(a) CT abdomen and pelvis showing circumscribed, heterogenous presacral mass with osteolytic lesion in the sacrum and coccyx; (b) smear with large cells (physalipherous cells) with bubbly cytoplasm (Pap, ×400); and (c) tumor with two distinct population of cuboidal cells and physalipherous cells in histopathology (H and E, ×100)