Subacute Sensorimotor Polyneuropathy as Sole Manifestation of Occult Non Hodgkin’s Lymphoma: Infiltrative or Paraneoplastic?

Abstract

Sir, The mechanisms of peripheral neuropathy in any malignancy can be because of a direct effect of the cancer by invasion or compression of nerves, a remote or paraneoplastic effect, or an iatrogenic effect of treatment. Focal or multifocal cranial neuropathies, radiculopathies, and plexopathies typically result from tumor infiltration, herpes zoster infection, or radiation-induced injury. Apart from sensorimotor polyneuropathies, which are the most frequently encountered peripheral nerve syndromes, motor neuropathies, sensory neuronopathies, polyradiculoneuropathies, and autonomic neuropathies can also occur. Although uncommon, paraneoplastic mechanisms should be considered in a patient with malignancy and an associated peripheral nerve disorder, especially in the setting of small-cell lung cancer or lymphoproliferative cancer [1]. A 63 years old, non alcoholic, male presented to us with chief complaints of tingling paresthesias in glove and stocking distribution of the limbs and mild weakness in feet since 3 months. The complaints were insidious in onset and were progressive. He gave history of inability to hold the chappals and frequent slipping of the chappals from feet. There were no weakness in the hands. He did not give any history suggestive of proximal muscle weakness. He was nondiabetic and was not taking any drugs. There was no history of fever of weight loss. General examination did not reveal anything significant apart from mild pallor. There was no evidence of postural hypotension. Examination of skin was normal and there were no thickened/tender nerves on palpation. Other systems examination was normal. In CNS examination higher functions, cranial nerves were normal. Motor system examination revealed mild weakness in plantar flexors of the ankle (patient was unable to stand on the ball of feet without support). Bilateral ankle and knee reflexes were lost. Sensory examination showed hyperasthesia in both legs up to knee joints, position sense was intact and vibration sensation was impaired up to both medial malleolus. On investigations Hb was 9 gm%, TLC 5500/mm3, DLC polymorphs 62%, lymphocytes 34%, monocytes 2%, eosinophil 2%, few atypical lymphocytes were seen. Absolute platelet count 225000/mm3. All red cell indices (MCV, MCH, MCHC) were within normal limits. Urine examination was normal. Liver and kidney function tests were normal. Fasting blood sugar 98 mg%, PPBS 138 mg%. Serum electrophoresis did not reveal any M spike. ELISA for HIV was negative. Bone marrow examination revealed marrow hyperplasia with some places showing infiltration by atypical lymphocytes. Thyroid profile was normal. CXR showed rounded, homogenous opacity in the left hilar region suggestive of mass (Fig. 1). USG abdomen was normal. EMG/NCV was conducted which revealed decreased nerve conduction velocities, prolonged distal latencies without any conduction block. Compound muscle action potential (CMAP) was normal, suggesting a predominantly demyelinating type of neuropathy. HRCT of thorax revealed left hilar mass (Fig. 2). A CT-guided FNA was done from the left hilar mass for cytological analysis and non Hodgkin’s lymphoma (NHL) was diagnosed (Fig. 3a, b). Immunophenotyping was carried out which was positive for CD 20 and CD 22 suggesting that the lymphoma was of B cell origin. Patient did not give consent for sural nerve biopsy and immunophenotyping. Anti neuronal antibodies status was not done because the patient could not afford. Fig. 1 Chest X-ray PA view showing left sided hilar opacity suggestive of mass Fig. 2 HRCT of thorax highlighting the mass and mediastinal lymphadenopathy Fig. 3 a, b Cytological smears 10× and 40× view stained with MGG stain showing cellular smears with predominant lymphocytic population. Lymphocytes are large and atypical with coarse chromatin and prominent nuclei, there is also presence of macrophages, ... He was started with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone), regime. He tolerated the first cycle well though there was no significant improvement in the symptoms of neuropathy and awaits the second cycle.