Solitary lymph node metastasis without local recurrence of primary chordoma

Abstract

Chordoma is a malignant neoplasm believed to arise from notochord remnants. Its incidence is highest in the sixth decade and is generally regarded as a locally aggressive tumor with slow progression growth rate. Its metastatic incidence ranges from 5 to 40%, and it is generally believed that metastases without local recurrence of primary neoplasm are extremely rare. We report a case of a 38-year-old male patient with solitary inguinal lymph node metastasis without local recurrence of a previously surgically treated primary sacrococcygeal chordoma.

Introduction

Chordoma is a malignant neoplasm believed to arise from notochord remnants. It accounts for approximately 3–4% of primary bone tumors and is localized along the axial skeleton [6, 22, 28]. This tumor develops predominantly in the sacrococcygeal (50%), spheno-occipital (35%) and cervical (15%) region and is generally regarded as a locally aggressive tumor with slow progression growth rate and metastatic incidence ranging from 5 to 40% [5, 20]. Its incidence is highest in the sixth decade, but it can also be found in younger population, even infancy (1%) [3, 4, 12, 26]. The male–female ratio among patients is 1.8–2.1.

Clinical, radiological (X-ray, CAT scan and MRI) and histological findings have been well discussed in the literature [7, 25]. Diagnostic certainty is based on histological examination, often suggestive of the diagnosis combined with ultrastructure and immunohistological study [2, 16, 23]. The clinical course involves local recurrences usually with realistic risk of metastatic development, notably in the sacrococcygeal chordomas case, with its incidence estimated at 17.5% of cases [5, 13, 24]. Sometimes developing in later stages of their course, histological findings are similar to those of the initial lesion. Mc Pherson stated that metastases without local recurrence of primary neoplasm are extremely rare. Organs which are frequently sites of metastases are: lung (48%), bones (26%) and sometimes liver. The sporadic cases of metastases in CNS [14], lymphatic organs [2, 5], breast [27] and skin and subcutaneous tissue [18] have been reported. Some cases of unusual clinical presentations of chordoma have also been emphasized [1, 19].

Macroscopically, this tumor mostly presents the lobular shape with fine fibro-vascular septas between the lobes. Microscopically, two distinct cellular patterns can be found: large, bright and vacuolated cells with excentric nucleus, called physaliphore-like cells and small, polygonal cells rich with eozinophylic cytoplasm and mild to moderate atypia of the nucleus [9, 17]. Both cell groups are arranged in band-like formations circumscribed by basophylic, mixoid stroma [22]. Mytoses are rare and not necessarily pathologic [28].

Immunophenotyping of the tissue samples enables the precise differentiation of chordoma from other neoplasms. This tumor has a strong positivity to vimentin (VIM), CK AE1/AE3 (pan-keratin), S-100 protein, epithelial membrane antigen (EMA) and CK (cyto-keratin) with low molecular weight [15, 21, 28].

Therapeutic management, ideally, consists of complete surgical excision of the initial tumor and adjuvant chemo or radio therapy [7, 8, 10].

Case report

This report is a case of a 38-year-old male patient with a history of an intermittent dull pain in the lumbosacral region of the spine without any neurological dysfunction, initially treated conservatively as a case of low-back pain syndrome. Due to slight paresthesias that occurred in both legs during treatment course, he underwent the X-ray and CAT scan diagnostic, which revealed expansive bone lesion of the sacrum. Further diagnostic with MRI delineated a 37 × 35 × 18 mm solitary tumor mass of nodular shape, with bone destruction and local infiltration of the surrounding muscular tissue. The incisional biopsy was done. (Fig. 1)

Fig.1.

MRI and CAT scan presentation of a sacral tumor mass which infiltrates the surrounding muscular tissue and destroys the bone

Microscopically, tumor was lobulated. Individual lobes were separated by fibrous bands. The cells were arranged in syncytial nests and cords, lying in pink mucinous stroma. The tumor cells presented typical “physaliphorous appearance” with an abundant, pale, vacuolated bubbly cytoplasm. They showed mild to moderate nuclear atypia. Mitoses were infrequent, 1-2/HPF. Histological diagnosis was chordoma (Fig. 2).

Fig. 2.

Chordoma-physaliphorous cells with vacuolated cytoplasm and prominent vesicular nucleus (H&E, 100×)

For further characterisation of tumor, immunoperoxidase staining for citokeratin (CK AE1/AE3), EMA, VIM, ans S-100 protein were performed by streptavidinbiotin peroxidase technique using universal detection kit (Immunotech™) Tumor cells showed diffuse reactivity with antibodies against VIM and S100 protein, and focal to mild reactivity with pan-keratin (CK AE1/AE3) and EMA. (Fig. 3)

Fig. 3.

Immunoprofile of chordoma: immunoreactivity for vimentin (a), CK AE1/AE3(b), and S-100 protein (c)

After definitive histopathologic diagnosis and in accordance with disease staging (local, extacompartmental lesion with infiltration of the surrounding muscles and subcutaneous tissue, absence of pulmonary dissemination) the radical surgery, meaning subtotal sacrectomy in the level of S2 segment, was performed through anterior and posterior approach simultaneously. Macro and micro analysis of the specimen obtaining at surgery confirmed the diagnosis. The width of the tumor’s pseudocapsula was 1,7 mm, and from the oncological point of view this was interpreted as a marginal surgical procedure.

The patient was regularly followed at 3 months intervals, with no clinical, MRI or CAT scan signs of local recurrence or dissemination. After 13 months, the patient noticed the painless mass in his left inguinum. The control MRI revealed an enlarged solitary lymph node in this region, 25 × 30 mm in diameter, without local recurrence of a neoplasm. The lungs were free of metastases. This was initially treated by antibiotics which showed no result after two weeks of treatment, after which the excision biopsy was done. The metastatic chordoma with identical histological and immunohistochemical characteristics of the primary tumor was confirmed. (Figs. 4, 5)

Fig. 4.

Lymph node involved by metastatic chordoma (a)-(H&E, 40×) Chordoma cells are positive for CK AE1/AE3 (b) and S-100 protein (c); LCA positive reaction in lymphoid tissue (d)

Fig. 5.

The control MRI and CAT scan, 13 months after index procedure, that delineates the solitary inguinal lymph node metastasis without local recurrence of tumor

Twenty-eight months after index procedure, the patient is now disease-free and he is regularly followed-up in 3 months intervals. He had no functional impairment of urinary bladder and he has completely restored physiological walking pattern.

Discussion

According to the literature, almost 17–35% of the patients with chordoma present signs of local recurrence within various period of time after surgery [11, 13, 20, 24]. This can be followed easily or even preceded by distant haemathogenous metastases, with lungs as a predominant site. That is why the regular MRI and CAT scan controls of all such patients are imperative, particularly in cases of a proven aggressive biological behaviour of a primary neoplasm. Very few authors described metastases in liver, skin or lymphatics. Solitary metastases without local recurrence of the primary tumor are supposed to be extremely rare [2, 5, 13, 20, 24].

To our best knowledge, there are just few cases in the literature that describe solitary lymph nodes metastases of chordoma, among whom we found not even one without verified local recurrence [2, 5, 26]. Furthermore, these patients, predominantly children or adolescents, were of younger age than usual for population of patients with chordoma. All of these cases ended lethally and were associated with already existing distant haemathogenous metastases in lungs or other organs.

The case here presented has almost all typical characteristics of chordoma: sacral localisation, non-specific clinical presentation in “low back pain” form and a long period of evolution. Radiological procedures that revealed an unclearly marginated large sacral mass that infiltrated and compromised the local muscles and other structures suggested the diagnosis of chordoma. The specific histological picture of a tumor samples obtained at surgery, showing mixoid tissue structure with well-defined physaliphorous cells, confirmed this presumption. Further immunophenotypisation of tumor cells with co-expression of VIM, cytokeratine, EMA and S-100 proteine excluded other types of neoplasms, such as chondosarcoma, metastatic lucidocellular carcinoma and lyposarcoma.

Solitary lymph node metastasis that we clinically, radiologically and immunohistologically verified in this patient 13 months after the index procedure, was not associated with local recurrence of primary neoplasm. We believe that this extremely rare clinical course and biological behaviour of primary chordoma represents rather unusual example in orthopaedic oncology.