Small Cell Lung Cancer Associated with Anti-Hu Paraneoplastic Sensory Neuropathy and Peripheral Nerve Microvasculitis: Case Report and Literature Review

Paraneoplastic Cerebellar Degeneration Associated with Breast Cancer: A Case Report and a Narrative Review

Paraneoplastic neurological syndromes (PNSs) are an uncommon complication of cancer, affecting nearby 1/10,000 subjects with a tumour. PNSs can involve all the central and peripheral nervous systems, the muscular system, and the neuromuscular junction, causing extremely variable symptomatology. The diagnosis of the paraneoplastic disease usually precedes the clinical manifestations of cancer, making an immediate recognition of the pathology crucial to obtain a better prognosis. PNSs are autoimmune diseases caused by the expression of common antigens by the tumour and the nervous system. Specific antibodies can help clinicians diagnose them, but unfortunately, they are not always detectable. Immunosuppressive therapy and the treatment of cancer are the cornerstones of therapy for PNSs. This paper reports a case of PNSs associated with breast tumours and focuses on the most common paraneoplastic neurological syndromes. We report a case of a young female with a clinical syndrome of the occurrence of rigidity in the right lower limb with postural instability with walking supported and diplopia, with a final diagnosis of paraneoplastic cerebellar degeneration and seronegative rigid human syndrome associated with infiltrating ductal carcinoma of the breast.

A Rare Case of Sensory Neuropathy Associated with Transitional Cell Carcinoma of the Bladder

Malignancies can trigger an autoimmune response against the nervous system and manifest as paraneoplastic neurological syndromes (PNS). Initial symptoms of PNS may develop up to 5 years prior to the diagnosis of the underlying malignancy. We report a rare case of PNS associated with transitional cell carcinoma of the bladder in a 70-year-old male with a 6-month history of rapidly progressive symmetric sensory neuropathy. Peripheral neuropathy serological workup was unremarkable. A paraneoplastic neuropathy panel revealed anti-Hu autoantibodies. Further evaluation with a whole-body PET scan could not identify the primary malignancy, but it showed hypermetabolic hilar lymph nodes. An endobronchial ultrasound biopsy of the hilar lymph nodes was negative for cancer. The patient developed painless hematuria 2.5 years after the onset of the sensory neuropathy. Cystoscopy with biopsy revealed non-muscle-invasive transitional cell carcinoma of the bladder. Progression of the sensory neuropathy stopped after tumor resection. This case highlights the importance of a diligent and systematic approach to diagnose PNS. A relentless search is often required to detect PNS-associated occult malignancies.

The great masquerader of malignancy: chronic intestinal pseudo-obstruction

Paraneoplastic syndromes can precede the initial manifestation and diagnosis of cancer. Paraneoplastic syndromes are a heterogeneous group of disorders caused by mechanisms other than the local presence of tumor cells. These phenomena are mediated by humoral factors secreted by tumor cells or by tumor mediated immune responses. Among paraneoplastic syndromes, chronic intestinal pseudo-obstruction (CIPO) is rare and represents a particularly difficult clinical challenge. Paraneoplastic CIPO is a highly morbid syndrome characterized by impaired gastrointestinal propulsion with symptoms and signs of mechanical bowel obstruction. Clinical outcomes of paraneoplastic CIPO are often deleterious. The current standard of care for the management of CIPO includes supportive treatment with promotility and anti-secretory agents. However, the majority of patients with CIPO eventually require the resection of the non-functioning gut segment. Here, we present a 62-year-old patient with anti-Hu antibody associated paraneoplastic CIPO and underlying small cell lung cancer who underwent treatment with cisplatin and etoposide. Herein, we discuss diagnosis, prognosis, proposed mechanisms, treatment options, and future potential therapeutic strategies of paraneoplastic CIPO.

Vasculitic neuropathies

The vasculitic neuropathies are a diverse group of disorders characterised by the acute-to-subacute onset of painful sensory and motor deficits that result from inflammatory destruction of nerve blood vessels and subsequent ischaemic injury. They are common in patients with primary systemic vasculitis and are seen in vasculitis secondary to disorders such as rheumatoid arthritis, viral infections, and diabetic inflammatory neuropathies. It is imperative that neurologists recognise these disorders to initiate treatment promptly and thereby prevent morbidity and mortality. To simplify the approach to patients with vasculitis of the peripheral nerves, a straightforward, dichotomous classification scheme can be used in which the vasculitic neuropathies are divided into two groups-nerve large arteriole vasculitis and nerve microvasculitis-on the basis of the size of the involved vessels. The size of the affected blood vessels correlates with the clinical course and prognosis in patients with vasculitic neuropathy.

Paraneoplastic neuropathy

Recent progress in serological screening of paraneoplastic antibodies and in diagnostic imaging techniques to detect malignancies has enabled a broadening of the concept of paraneoplastic neurological syndromes by integrating nonclassic clinical features. The peripheral nervous system is frequently involved in patients with paraneoplastic syndrome and may be seen alone or in combination with involvement of other areas of the nervous system. Destruction of dorsal root ganglion cells due to lymphocytic infiltration, especially with CD8-positive cytotoxic T cells, has been postulated to mediate the classic syndrome of subacute sensory neuronopathy. However, the motor and autonomic nervous systems are frequently affected. Indeed, patients can develop clinical features compatible with Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, or brachial plexopathy. Other forms of paraneoplastic neuropathy are vasculitic neuropathy, autoimmune autonomic ganglionopathy, and chronic intestinal pseudo-obstruction. Various onconeural antibodies, including anti-Hu, anti-CV2/CRMP-5, and anti-ganglionic acetylcholine receptor antibodies, are associated with neuropathy. Somatic neuropathy is the most common manifestation in patients with anti-Hu and anti-CV2/CRMP-5 antibodies, while anti-ganglionic acetylcholine receptor antibody is associated with autonomic neuropathies. A whole-body fluorodeoxyglucose positron emission tomography scan may be useful to detect malignancy in patients with unremarkable conventional radiological findings. Recognition and diagnosis of paraneoplastic neuropathy is important, as neuropathic symptoms usually precede the identification of the primary tumor, and treatment at an earlier stage provides better chances of good outcomes.

Paraneoplastic sensory neuropathy associated with small cell carcinoma of the gallbladder

A small number of patients with carcinoma of the gallbladder can present with a variety of paraneoplastic syndromes, including the Cushing syndrome, hypercalcemia, acanthosis nigricans, bullous pemphigoid, dermatomyositis, and the Leser-Trélat sign. We report on what appears to be the first case of a patient, a 48-year-old woman, with anti-Hu paraneoplastic sensory neuropathy and small cell carcinoma of the gallbladder. The patient's neurologic symptoms preceded the diagnosis of small cell carcinoma by 11 months. These symptoms improved after surgical removal of the tumor and chemotherapy. The small cell carcinoma was relatively small and was not associated with gallstones. In spite of the small size of the tumor, it metastasized to a celiac lymph node and probably to the liver. Anti-Hu paraneoplastic sensory neuropathy should be added to the list of paraneoplastic syndromes associated with small cell carcinoma of the gallbladder.

Diagnosis and current treatment of neurological paraneoplastic syndromes

Neurological paraneoplastic syndromes (NPS) affect only 0.01% of cancer patients, chiefly those affected by lung, breast, ovarian and stomach cancer. They frequently cause major disability and produce limitations in patients' daily activities; the character of the disease is irreversible. Clinical suspicion is fundamental for an early diagnosis and it must be backed up by the specification of certain antibodies both present in blood and in cerebrospinal fluid (CSF). Conventional treatments are very inefficient at the time of treating these disorders; at present, the administration of immunoglobulins, immunosuppressors, chemotherapy agents and corticoids are under study, but so far results are not promising. The aim of this review is to analyze the variety of NPS and describe the findings concerning autoimmunity and treatments used at present.

Paraneoplastic syndromes of the peripheral nerves

PURPOSE OF REVIEW

To describe the paraneoplastic disorders of the motor and sensory nerves and neurons, and their immunologic associations.

RECENT FINDINGS

Recently proposed diagnostic criteria for paraneoplastic disorders may assist in determining the likelihood a given neuropathy or neuronopathy is related to an underlying malignancy. Of this group of disorders, paraneoplastic sensory neuronopathies are the most frequent; many of these patients have anti-Hu antibodies and small-cell lung cancer. There is often motor, autonomic, or central nervous system involvement, and electrophysiological studies may demonstrate not only sensory changes, but also motor abnormalities. While cancer has been found more frequently than expected in patients with Guillain-Barré syndrome, this association is extremely rare. A limited number of reports have described chronic inflammatory demyelinating polyradiculoneuropathy, multifocal motor neuropathy with conduction block, vasculitic neuropathies, and motor neuron disease as paraneoplastic disorders. Anti-CV2 antibodies are frequently associated with a paraneoplastic sensorimotor axonal neuropathy and small-cell lung cancer. Peripheral nerve hyperexcitability may occur with or without a cancer association, and in both instances patients often have antibodies to voltage-gated potassium channels; thymoma and small-cell lung cancer are the most common underlying tumors. Plasma cell proliferative disorders are frequently associated with neuropathies, particularly demyelinating ones.

SUMMARY

There is increasing recognition of an extensive variety of paraneoplastic disorders of the peripheral nerves. In many of these disorders onconeuronal antibodies are absent. Whole body fluorodeoxyglucose positron emission tomography scanning helps uncover the associated tumor, and recently proposed criteria may assist in the diagnosis. In many instances, prompt treatment of the tumor and immunotherapy result in symptom stabilization or neurologic improvement.

Octreotide treatment for paraneoplastic intestinal pseudo-obstruction complicating SCLC

Small cell lung cancer (SCLC) is often associated with paraneoplastic neurological syndromes like intestinal pseudo-obstruction. This syndrome is characterized by dysmotility of the bowel without mechanical obstruction. The pathogenesis of the syndrome is thought to involve autoimmune mechanisms with production of antineuronal antibodies and enteric neuronal degeneration. We report a patient with severe constipation as a clinical presentation of a paraneoplastic intestinal pseudo-obstruction complicating SCLC, who was successfully treated with the somatostatin analogue octreotide. This may be explained by effects of hormone-like substances from the tumor directly inhibiting the gut motility, rather than by autoimmune mechanisms.