20 YEAR OLD LADY WITH A PARASPINAL MASS

CLINICAL HISTORY

A 20 year old woman attended her general practitioner with right upper limb pain and intermittent paraesthesias for a 4 month period. She had no neck pain or systemic symptoms and was a non smoker. There was no family history of note. She was commenced on pregabalin for pain and an MRI of cervical spine was ordered. The MRI revealed a right‐sided intradural extramedullary mass extending from C7‐T1 that was displacing the spinal cord to the left. She was reviewed by neurosurgery and was now complaining of paraesthesias in the right lower limb also. She had no bowel or bladder symptoms. Her examination revealed reduced sensation in the right upper limb but normal tone, power, coordination and reflexes. Cranial nerves, the left upper limb and bilateral lower limb examination were documented as normal. Imaging revealed that the lesion now extended from C5 to T3 and was causing significant cord compression at C7‐T1. An enhancing extradural soft tissue mass centered in and expanding the exit foramina and indenting the thecal sac (arrow) is shown by axial T1 MRI post‐contrast (Figure 1). On the T2 Sagittal MRI (Figure 2) the low signal soft tissue mass is demonstrated in the right exit foramina at four spinal levels(small arrows), normal high signal fat is seen in the foramen below (larger arrow). (Figure 2) The patient underwent emergency resection of the lesion. A large rubbery, tan piece of tissue measuring 1.5 × 0.8 × 0.5 cms and further multiple pieces of cream grey tissue measuring 3.5 × 3 × up to 0.3 cm in aggregate were removed.

Figure 1.

Figure 2.

PATHOLOGY

Paraffin sections showed a nodular and diffuse cellular infiltrate with intervening fibrous bands. The cellular areas contained sheets of histiocytoid cells with scattered large pleomorphic cells with prominent eosinophilic nucleoli (Figure 3). Admixed with these were eosinophils and plasma cells. No classic Reed Sternberg cells were identified. Immunocytochemistry for CD30 and CD15 were positive in the larger cells (Figure 4). These cells were negative for CD21, CD23 and ALK.

Figure 3.

Figure 4.

FINAL DIAGNOSIS

Hodgkins disease‐mixed cellularity type.

DISCUSSION

This case was complex and surprising in that by pre‐operative radiological studies the patient was felt to have a plexiform neurofibroma. Definitive diagnosis was not made at frozen section. The differential pathological diagnosis initially included follicular dendritic cell sarcoma, anaplastic Large Cell Lymphoma (ALK) or Hodgkin's Disease. Post operative scans showed extensive nodular residual mass extending into the soft tissues of the neck from the paraspinal region to deep to the sternocleidomastoid muscle. An incidental superior mediastinal mass lesion was noted adjacent to the trachea of mixed signal intensity with co‐existent lymphadenopathy in both supraclavicular fossae. CT of thorax, abdomen and pelvis was carried out to further characterize the mediastinal lesion and look for other evidence of lymphadenopathy elsewhere. No other lesions were identified. A CT guided biopsy of the posterior mediastinal mass was carried out. This revealed features consistent with Hodgkin's lymphoma. Bone marrow biopsy was negative. Patient was considered to have stage IV Hodgkin's mixed‐cellular type. The patient has been commenced on ABVD chemotherapy, she is currently undergoing her fourth cycle.

Primary CNS‐Hodgkin's lymphoma (CNS‐HL) is exceedingly rare with a reported incidence of 0.02–0.5% of all HL cases 6, 9. The literature available consists of case reports and small case series. Common presentations include cranial nerve palsies, motor/sensory deficits, headache, visual disturbance, seizures and coma (8). Parenchymal disease is most common followed by dural based disease (6). Paraspinal or spinal masses are not well described. Involvement of the dura mater may be de novo or may involve spread from a contiguous parenchymal lesion or metastases from systemic HL 3, 5, 10. Median age at diagnosis is approximately 25 years (6). There is a reported increased risk of CNS involvement in HL of a mixed‐cellularity type (as in our patient) which accounts for up to 44% of CNS cases of HL (1). In a recent case series of 16 patients with CNS‐HL, 8 patients had CNS‐HL occurring as a relapse of systemic disease, 2 had primary CNS‐HL and 6 patients had evidence of systemic HL although it was initially discovered in the CNS. 5 cases had dural based non parenchymal tumors (10). Although dural based HL mimicking meningioma has been described there are no previous reports of HL mimicking a plexiform neurofibroma in the literature (4). In contrast there have been several cases of NHL mimicking both neurofibromatosis and meningiomas 2, 7. Because CNS involvement is rare in HL there is no consensus on therapy although various combinations of surgery, chemotherapy and radiation therapy were used in the recent series reported by Gerstner et al Chemotherapy regimes varied widely. Our patient is currently receiving ABVD which was used in 2 patients in the Gerstner cohort with 50% success rate (5). This case is unusual because CNS‐HL involvement is extremely rare especially extracranially. When it does present in this fashion there may be evidence of systemic disease and the most common histological subtype is mixed cellularity‐HL as in our patient. There are no previous reports of HL radiologically appearing identical to a paraspinal plexiform neurofibroma in the literature.

ABSTRACT

A 20 year old female presented with a 4 month history of right upper limb pain and paraesthesias. She had no systemic symptoms and no prior medical or family history of note. MRI revealed a right‐sided intradural extramedullary mass extending from C7‐T1 and displacing the spinal cord. While awaiting surgery her symptoms progressed to involve the right lower limb. She was re‐imaged and the lesion now extended from C5 to T3 with spinal cord compression at C7‐T1. The radiological features and recent rapid growth were felt to be in keeping with a large plexiform neurofibroma. The patient underwent emergency resection of the lesion and pathology revealed Hodgkin's Lymphoma (HL)—mixed cellularity type. A mediastinal mass was identified on further imaging and biopsy confirmed the diagnosis of HL‐stage IV. The patient is currently undergoing treatment with ABVD chemotherapy. CNS‐HL is extremely rare and may occur de novo or in association with systemic disease. Lesions may be parenchymal or dural based and are usually intracranial with an increased risk of CNS involvement in HL‐mixed‐cellularity type as in our patient. This is the first report in the literature of CNS‐HL radiologically mimicking a paraspinal plexiform neurofibroma.