In a normal lat. CXR, we cannot visualize the spine clearly at the shoulder region due to all the bones and dense tissue. But as we descend down to the lumbar region, it appears darker (and clearer). This is called sometimes "the more-black sign."

In a lower lobe pneumonia, especially in the posterior region, the consolidation affects the visualization of the spine. So instead of appearing darker and clearer as we go down, it gets more obscure. This is called "the spine sign."

Sometimes, the embryonic tissues that would become the spleen fail to fuse with one another, and as a result, the individual would have a normal spleen in its normal position, and an accessory spleen.

Also, the accessory splenic tissue can attach to the embryonic gonadal tissue and descend with it in a condition called "splenogonadal fusion".

Splenosis is when the spleen divides due to trauma and injury, and the remaining tissue grows as an accessory spleen in addition to the main one.

About 10% - 15% of the population have at least one accessory spleen. And it can misdiagnosed as a neoplasia or a lymph node.

Splenogonadal fusion in which the spleen is attached to the left testis of a 1 year-old.

Here's this really interesting case of a 15-year-old boy who was admitted to the emergency department following blunt abdominal trauma.
The computed tomographic scan showed a traumatic rupture of the spleen and a 7-cm mass at the left side of the retroperitoneal space. Conservative treatment started and aborted after 4 h due to the onset of haemodynamic instability. Splenectomy was performed. And an accessory spleen was discovered. A second large mass in the retroperitoneum was diagnosed as a second large accessory spleen that was also left in place. The postoperative course was uneventful, and the patient was discharged on the 7th postoperative day. Seven months later, the CT scan showed viability of both accessory spleens.

باختصار: صار عنده splenic rupture بس طلع عنده two accessory spleens عوضن مكان الأصلي😂

The boy's accessory spleens after the original spleen ruptured:

S6 E9 of House MD shows this condition

A terrible side-effect of anti-dopaminergic drugs (neuroleptic drugs). Patients with schizophrenia, bipolar, and fetal alcohol syndrome are a lot more susceptible for this side-effect.

GBV-C virus (formerly known as hepatitis G virus, HGV) seems to have protective effect on HIV patients. Many studies have shown that it reduces the morbidity and mortality of HIV infection, especially those associated with liver cirrhosis.

باختصار: فايروس الـ GBV-C ممكن يقلل شدة الـ HIV infection

Etiology

ERCP: Endoscopic Retrograde CholangioPancreatography

Clinical presentation

Differential diagnosis

Workup