[Bilateral mental neuropathy revealing prolymphocytic transformation of chronic lymphocytic leukemia]

Mental neuropathy: report of five cases and review of the literature

Mental nerve neuropathy, also referred to as numb chin syndrome, is a rare, seemingly harmless symptom. It is more often associated with cancer, either as first symptom or during the outcome, than with benign diseases. In this review, we will focus on the numb chin syndrome presenting as an isolated neurological symptom. We report five patients with mental nerve neuropathy associated with metastatic disease (small cell lung cancer, prostatic cancer and breast cancer). In one patient, numb chin syndrome preceded the discovery of the disease, while, in the four others, it occurred as a sign of relapse or progression. Isolated mental nerve neuropathy, frequently associated with breast cancer and lymphoproliferative diseases, is generally thought to be the consequence of bone metastases or leptomeningeal seeding, but may also present without an obvious cause, most often secondary to the involvement of the mental nerve itself. Although various therapies may lead to the resolution of this symptom, median survival after diagnosis is generally less than 1 year. The appearance of a mental nerve neuropathy should never be considered as a 'banal' symptom and investigations to detect a possible cancer should be mandatory.

Inflammatory neuromuscular disorders associated with chronic lymphoid leukemia: evidence for clonal B cells within muscle and nerve

It is frequently difficult to determine whether a neuromuscular disorder (NMD) related to a lymphoproliferative disease is neoplastic, paraneoplastic, or incidental. This may explain why neuromuscular complications of chronic lymphoid leukemia (CLL), a frequent disorder, have been rarely reported. We describe 7 patients with CLL and neuromuscular involvement in whom phenotypic and genotypic characterization of infiltrating lymphoid cells was carried out by immunocytochemistry and PCR-amplification of immunoglobulin heavy chain locus. One patient had massive neoplastic infiltration of muscle, and six presented with inflammatory-like NMDs (dermatomyositis: 2, polymyositis: 1, vasculitic mononeuropathy: 2; inflammatory demyelinating neuropathy: 1). Immunocytochemistry on nerve and muscle frozen sections showed a monotypic lymphoid cell population in 3 cases and failed in 4 cases. The PCR analysis of immunoglobulin heavy chain gene (FR3-FR4) rearrangement detected clonal B-cells in all biopsy specimens. There are arguments suggesting that incidental or paraneoplastic inflammatory NMDs may progress to neoplastic infiltration in CLL patients, as a result of the traffic of tumor B-cells from circulation to nerve and muscle tissues. This may question the traditional distinction between inflammatory and neoplastic NMDs in patients with lymphoid cell proliferations.