The patient is most likely a case of haemophilia A which is the genetic deficiency of clotting factor VIII in blood.

Haemophilia is an X-linked recessive disorder of coagulation. Up to 30% of patients have no family history of the condition. Haemophilia A is more common than haemophilia B and accounts for 90% of the cases. In haemophilia B (Christmas disease), there is a deficiency of clotting factor IX.

Characteristic features of haemophilia include hemarthrosis, haematomas, and prolonged bleeding following trauma or surgery. Coagulation profile of a haemophiliac person shows prolonged bleeding time, activated partial thromboplastin time (APTT), thrombin time (TT), but a normal prothrombin time (PT).

Constitutional symptoms such as weight loss, evening pyrexia and night sweats are associated with Mycobacterium Tuberculosis (TB). TB can affect any system of the body and should be top in the list of differentials particularly if the patient has a history of contact with a known TB patient.

The most common location for a duodenal ulcer bleed is the posterior duodenum (remember: posterior bleeds, anterior perforates). The perfusion to this area is most specifically from the posterior superior pancreaticoduodenal artery.

The anterior superior pancreaticoduodenal artery supplies the anterior region. The gastroepiploic artery supplies mostly the stomach. The splenic artery goes, obviously, toward the spleen, in the other direction. The gastroduodenal artery is a branch of the celiac artery, and it’s branches are the anterior superior pancreaticoduodenal artery and posterior superior pancreaticoduodenal artery.

The patient has Cushing syndrome suggested by the elevated 24hr urine free cortisol. Hence, the mass is most probably a cortisol secreting adenoma.

Cystinuria is strongly suspected because of the recurrent passing of cystine stones and otherwise non-remarkable medical history of this young adult patient. Like Cystinuria, all the conditions listed are also inherited disorders, however, the other differentials usually present in the early years of childhood, usually with failure to thrive.

The most probable diagnosis of this patient is Cotard syndrome.

Cotard syndrome is a rare mental disorder where the affected patient believes that they (or in some cases just a part of their body) is either dead or non-existent. This delusion is often difficult to treat and can result in significant problems due to patients stopping eating or drinking as they deem it not necessary. Cotard syndrome is often associated with severe depression and psychotic disorders.

Other delusional syndromes:
– Othello syndrome is a delusional belief that a patients partner is committing infidelity despite no evidence of this. It can often result in violence and controlling behaviour.
– De Clerambault syndrome (otherwise known as erotomania), is where a patient believes that a person of higher social or professional standing is in love with them. Often this presents with people who believe celebrities are in love with them.
– Capgras syndrome is characterised by a person believing their friend or relative had been replaced by an exact double.
– Couvade syndrome is also known as ‘sympathetic pregnancy’. It affects fathers, particularly during the first and third trimesters of pregnancy, who suffer the somatic features of pregnancy.
– Ekbom syndrome is also known as delusional parasitosis and is the belief that they are infected with parasites or have ‘bugs’ under their skin. This can vary from the classic psychosis symptoms in narcotic use where the user can ‘see’ bugs crawling under their skin or can be a patient who believes that they are infested with snakes.

This man has a small-cell lung cancer (SCLC) and associated Lambert-Eaton myasthenic syndrome – a well-recognized paraneoplastic manifestation of SCLC. This classically affects the proximal muscles, especially in the legs, causing difficulty in standing from a seated position and climbing stairs. In contrast to myasthenia gravis, eye involvement is uncommon. Treatment with steroids is often helpful, which explains his transient symptomatic improvement during treatment for his COPD exacerbation. Steroid myopathy does not fit as the symptoms started well before his course of prednisolone. Although the patient is mildly hypercalcaemic, this would not be sufficient to produce his presenting symptoms, although it does reinforce the suspicion of lung malignancy. Motor neurone disease would be unlikely in this context and would not improve with steroids. Myasthenia gravis could produce these symptoms, but in the context of a new lung mass is a less viable diagnosis.

Scleritis, or inflammation of the sclera, is usually painful whereas episcleritis is not painful.

Keratoconjunctivitis sicca is usually bilateral and associated more with dryness, burning and itching.

Post-primary pulmonary tuberculosis is a chronic disease commonly caused by either endogenous reactivation of a latent infection or exogenous re-infection by Mycobacterium tuberculosis.
Post-primary pulmonary tuberculosis (also called reactivation tuberculosis) develops in 5%–20% of patients infected with M. tuberculosis.

Found mainly in adults, this form of tuberculosis arises from the reactivation of bacilli that lay dormant within a fibrotic area of the lung. In adults, reinfection with a strain of mycobacterium that differs from that which caused the primary infection is also possible. Predisposing factors include immunosuppression, diabetes, malnutrition and alcoholism.

Infliximab is a monoclonal antibody against tumour necrosis factor α (TNF-α). It is FDA approved for many autoimmune conditions, including rheumatoid arthritis and Crohn’s disease. One of the many known side effects of infliximab therapy is reactivation of latent tuberculosis (TB). Because of the resemblances in clinical and radiological features, tubercular lesions in the lung may mimic malignancy. TB accounts for 27% of all infections initially presumed to be lung cancer on imaging studies.

Oculomotor nerve palsy is an eye condition resulting from damage to the third cranial nerve or a branch thereof. A complete oculomotor nerve palsy will result in a characteristic down and out position in the affected eye. This is because the lateral rectus (innervated by the sixth cranial nerve) and superior oblique (innervated by the fourth cranial or trochlear nerve), is unantagonized by the paralyzed superior rectus, inferior rectus and inferior oblique. The affected individual will also have a ptosis, or drooping of the eyelid, and mydriasis (pupil dilation), not miosis.