Parachordoma or chordoma periphericum? Case report of a tumor of the thoracic wall

Abstract

We report the findings from an aspiration biopsy and resection of a chordoma-like tumorous mass in the wall of the thorax of a 36-yr-old man with immunohistochemical, ultrastructural, and cytogenetic studies. The 4-cm oval tumor was an incidental finding on physical examination, and no other lesions were identified after comprehensive radiologic studies. The aspirate was composed of sheets and nests of cells with distinct borders in a myxoid and fibrillary extracellular matrix. The neoplastic cells were uniform and round or polygonal with abundant pale blue vacuolated cytoplasm and small round, central or eccentric nuclei. On electron microscopy, mitochondrial rough endoplasmic reticulum complexes were seen in neoplastic cells. These features were similar to those of a conventional chordoma. However, the cytogenetic pattern, 43, XY ,-1, -2, der (5)t(1p;5q), -6, add(8p) ,add(10q), was not typical. In addition, the neoplastic cells were positive for vimentin, S-100, AE1/AE3, CAM 5.2, and CK 19; were focally positive for EMA and smooth muscle actin; and were negative for cytokeratin 1 and 10 (34 beta E12), CK 7, CK 8 (35H 11B), CK 17, and CK 20. The cytogenetic and immunohistochemical patterns were different from conventional chordoma and its peripheral counterpart, chordoma periphericum, suggesting the diagnosis of parachordoma. To the best of our knowledge, this is the first report of fine-needle aspiration of this newly defined and rare entity.

Cytopathology of extraskeletal myxoid chondrosarcoma

“…However, we have not encountered any cytologic examples of this neoplasm, and its cytopathology has only rarely been described. 31 Even so, ancillary immunostaining should differentiate between these 2 neoplasms, as the latter is routinely cytokeratin-positive, whereas EMC is not.…”

A case of parachordoma on the chest wall and literature review

“…It mainly occurs in the deep soft-tissue of the distal parts of the limbs, such as deep fascia, muscle tendon, synovial or soft-tissue closed to the bone, although nares, groin, pelvis and buttock has reported, [3] Spivach et al also reported a parachordoma located on the gastric serosa. [4] In 2003, World Health Organization (WHO) tumor classified parachordoma, mixed tumor of soft-tissue and myoepithelioma as the tumor whose purported origin is unknown.…”

Possible parachordoma in a dog

“…One case report established that parachordomas were positive for vimentin, AE1/AE3 and S-100 protein (Tong et al 2003), whereas a study of four cases found the tumours were negative to AE1 and GFAP (Fisher and Miettinen 1997). In a study by Kasantikul and Shuangshoti (2006), it was found that most, but not all, chordomas had cells that exhibited a positive reaction to GFAP; whereas a previous report found that all the parachordomas strongly expressed EMA, vimentin, S-100 protein and CK 8/18 but not other cytokeratins, smooth muscle actin, smooth muscle myosin heavy chain or GFAP (Folpe et al 1999).…”

“…They are most commonly found in dermal or S/C tissue on the extremities adjacent to tendons, synovia and bones, although they have been diagnosed at other sites including the forehead, chest wall, gastric serosa, nasal cavity and buttocks (Hirokawa et al 1994;Imlay et al 1998;Tihy et al 1998;Folpe et al 1999;Tong et al 2003;Spivach et al 2007). Cytologically and histologically they resemble chordomas, tumours derived from notochord remnants, that have been described in people (Imlay et al 1998), dogs (Jabara and Jubb 1971;Munday et al 2003), cats (Carpenter et al 1990), rats (Tanaka et al 1993), mink (Mustela vison) (Hadlow 1984) and ferrets (Mustela putorius furo) (Roth and Takata 1992).…”