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​Pathology - Amyotrophic Lateral Sclerosis
The cause of sporadic amyotrophic lateral sclerosis (ALS) is unknown. 5%-10% of cases are familial and are inherited by autosomal dominant inheritance of a mutation on chromosome 21 or a deficiency in the SOD-1 gene, which is involved in scavenging free radicals.
Primarily impacts males over the age of 40.

Progressive illness linked to the deterioration of both upper and lower motor neurons.
Spinal cord: Decreased anterior horn neurons with reactive gliosis; degeneration of corticospinal tract neurons.

Neurogenic atrophy of muscle with target fibers (fibers showing a dark center area on cross-section).

Lower motor neuron indications include muscular atrophy and fasciculations.
Upper motor neuron indications include hyperreflexia, positive Babinski sign, and spasticity.
Motor neuron degeneration typically manifests with first symptoms of hand weakness, cramping, and spasticity in the arms and legs. Engagement of respiratory muscles results in lung infections and ultimately mortality.

Therapy
​Supportive Measures 
Respiratory failure typically leads to death within 5 years of being diagnosed.

Werdnig-Hoffmann syndrome is an autosomal recessive disorder that impacts the lower motor neurons and is linked to the degradation of anterior horns. It manifests in infancy with tongue fasciculations and symptoms of a weak or floppy newborn.
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​Pathology - Prostate Carcinoma
Risk factors include a family history of prostate cancer or being of African American descent.
Prevalent in males over the age of 50; the most frequent cancer in men and the second most prevalent cause of cancer-related deaths in men.

Gross: Irregular nodules originating from glands in the periphery zone of the posterior lobe.
Microscopic examination reveals adenocarcinoma characterized by well-defined glands lined by cuboidal cells with big nuclei and conspicuous nucleoli. It may also present as undifferentiated with cells developing in cords or sheets, often showing invasion of vascular or lymphatic arteries of the prostatic capsule.
In advanced stages, it can develop into bone osteoblastic metastasis by the spread of cancer cells in the bloodstream.

Often without symptoms, but can cause dysuria, increased urine frequency, or back pain (if cancer has spread to bone); typically identified during a digital rectal examination by detecting an irregular, enlarged, firm lump, and confirmed with a prostatic biopsy.
Lab results show elevated serum levels of PSA and prostatic acid phosphatase, which are useful indicators of tumor growth. There is also an increase in total PSA with a decrease in the free PSA fraction, as well as elevated serum alkaline phosphatase, indicating possible osteoblastic metastasis.

Treatments include prostatectomy, radiation, GnRH analogues (leuprolide), antiandrogens (e.g., flutamide), and chemotherapy.
The Gleason system of grading predicts whether prostate cancer will progress slowly or rapidly depending on the tumor's differentiation.

Annual PSA tests and digital rectal examination should be provided for screening starting at age 50.
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​Pathology - Penile Diseases 
Conditions known as Hypospadias and Epispadias

Definition: Congenital anomaly causing the urethral opening to be located abnormally on the underside (hypospadias) or top side (epispadias) of the penis; often linked with undescended testicles and abnormalities in the urinary system (bladder exstrophy).
Clinical symptoms: Obstruction of the urinary tract and abnormal ejaculation.

Phimosis is the condition when the foreskin is abnormally tight and cannot be pulled back over the head of the penis. It is typically caused by a congenital issue or can occur from inflammation or injury.
Clinical symptoms: Manifests as pain in the penis or sudden inability to urinate.

Peyronie's disease is characterized by the development of fibrous scar tissue on the dorsum of the penis, with the cause being unknown.
Clinical symptoms: Abnormal bending of the penis or narrowing of the urethra that happens in elderly males.

Balanitis is the inflammation of the glans penis, typically caused by various infections such as syphilis, gonorrhea, herpes, chancroid, Candida, and Gardnerella.
Clinical symptoms: Penile infections are more common in uncircumcised men who have inadequate hygiene.
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​Pathology - Penile Cancer 
Bowen's disease impacts men over the age of 50 who are not circumcised.
Erythroplasia of Queyrat typically occurs in individuals in their fifth decade and is considered a form of Bowen's disease.
Bowenoid papulosis primarily affects a younger demographic.
Penile Squamous Cell Carcinoma has a higher occurrence in Asia and Africa, typically affecting those aged 40-70. Risk factors include being uncircumcised, having poor hygiene, and being infected with HPV types 16, 18, 31, and 33.


Bowen's disease is characterized by the abnormal growth of epidermal cells with atypical cell divisions, although the basement membrane between the epidermis and dermis remains intact.
Erythroplasia of Queyrat and Bowenoid Papulosis are histologically similar to Bowen Disease.

Penile Squamous Cell Carcinoma originates from Bowen Disease and Erythroplasia of Queyrat. Papillary lesions resemble condyloma acuminata and form a cauliflower-like mass. Flat lesions present as thickened regions of epithelium with mucosal fissuring.

Bowen's disease presents as a single red patch on the penis or scrotum; less than 10% progress to invasive cancer and is linked to a higher chance of developing internal malignancies.

Erythroplasia of Queyrat presents as a solitary red patch on the glans penis or prepuce, with a 10% chance of progressing to aggressive cancer.
Bowenoid Papulosis is characterized by many wart-like lesions similar to condylomata acuminatum, although it does not develop into aggressive cancer.

Penile Squamous Cell Carcinoma is a painless lesion that can bleed, develop secondary ulceration, and become infected.
Excision of penile squamous cell cancer. 
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​Pathology - Congenital CNS Abnormalities
Neural Tube Defects 
Cause: Linked to low levels of folate during early pregnancy and high levels of alpha-fetoprotein.

Spina bifida is a condition where the posterior end of the neural tube fails to close properly, leading to a bony defect in the vertebrae. This defect can cause the meninges to herniate (meningocele) or both the meninges and spinal cord to herniate (meningomyelocele), resulting in neurological symptoms. In some cases, the bony defect may not cause any symptoms other than changes in the skin over the affected area, known as spina bifida occulta.


Encephalocele is a condition where a defect in the cranium causes the brain to protrude through the skull.
Anencephaly is the incomplete closure of the anterior end of the neural tube, leading to the lack of the fetal brain and sometimes the skull covering it.
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Spina Bifida

​Holoprosencephaly is a condition where the forebrain of the embryo fails to split into bilateral cerebral hemispheres, resulting in insufficient separation of the cerebral hemispheres.

Clinical symptoms: Facial and neurological abnormalities.
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Holoprosencephaly

​Arnold-Chiari Malformation is a condition where the cerebellum and medulla are displaced via the foramen magnum due to a tiny posterior fossa.
Symptoms and signs: Hydrocephalus is closely linked to thoracolumbar meningomyelocele and syringomyelia.


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​​Arnold-Chiari Malformation is a condition where the cerebellum and medulla are displaced via the foramen magnum due to a tiny posterior fossa.
Symptoms and signs: Hydrocephalus is closely linked to thoracolumbar meningomyelocele and syringomyelia.
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​Dandy-Walker Malformation is a condition where there is a big space in the back of the brain with the cerebellar vermis replaced by a massive cyst. It is also linked to abnormalities in the brainstem nuclei.
Symptoms: Seizures and malfunctioning of the cerebellum.

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Pathology - Tuberous Sclerosis 
Autosomal dominant condition caused by a mutation in one of several genes.

Pathology 
A brain hamartoma, also known as a cortical tuber, is a solid nodule found in the cerebral cortex. It is made up of a disordered arrangement of neurons with large vesicular nuclei and eosinophilic cytoplasm.
Additionally linked to tumors that develop outside the central nervous system, such as cardiac rhabdomyomas, adenoma sebaceum on the face (a lesion made up of deformed blood vessels), renal angiomyolipomas (a lesion composed of deformed blood vessels, adipocytes, and smooth muscle), and cysts in the bone and lung.

Symptoms and Signs 
Infants may experience seizures and developmental delay. They may also develop red nodules on the face known as adenoma sebaceum between the ages of 5 and 10. Other symptoms may include issues associated to heart rhabdomyoma and renal angiomyolipoma.

Treatment involves managing symptoms such as controlling seizures and providing genetic counseling.
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​Pathology - Multiple Sclerosis 
The cause is unidentified, but autoimmune, genetic, and environmental factors are suspected.
Incidence rises with distance from the equator and is more prevalent in individuals with HLA-DR2.
Typically occurs in Caucasian women aged 20 to 30.

Study of diseases 
CNS: Numerous solid plaques indicating demyelination in the white matter of the CNS, particularly in the optic nerve, brainstem, and periventricular regions.
Microscopic examination reveals a reduction in oligodendrocytes, presence of monocytes, lymphocytes, and lipid-laden macrophages around blood vessels, as well as gliosis and increased astrocyte growth.

Symptoms and signs 
The disease follows a pattern of relapse and remission, with remissions becoming incomplete over time. Symptoms include the classic Charcot triad of nystagmus, scanning speech, and intention tremor, as well as motor and sensory impairments affecting the trunk and extremities (hemiparesis, ataxia), visual impairment (optic neuritis, retrobulbar neuritis, internuclear ophthalmoplegia), and urinary/bowel incontinence due to sphincter control loss.

Lab results: Lumbar puncture indicates a slight increase in lymphocytes and high lgG levels, demonstrated by the presence of numerous oligoclonal bands on electrophoresis.

Treatment includes corticosteroids and other immunomodulator drugs such as ~-interferon and natalizumab.
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​Pathology - Guillain-Barre Syndrome 
Typically follows a flu-like viral infection (such as EBV, HSV, CMV), but can also be linked to surgical operations and bacterial infections (Mycoplasma, Campylobacter).

Study of the biological processes that lead to disease. A viral infection triggers an immunological response mediated by T-cells, leading to the demyelination of peripheral nerves.

Peripheral nerves show infiltration by lymphocytes and macrophages in the endoneurium and perivenular areas, along with segmental demyelination.

Clinical Symptoms and Signs 
Progressive muscle weakness and paralysis starting in the furthest lower limbs; lack of deep tendon reflexes; occasional sensory loss in limbs; facial weakness in both sides; aberrant autonomic function (irregular heartbeats, unstable blood pressure).
May advance to respiratory failure or develop into chronic inflammatory demyelinating polyradiculoneuropathy.
Laboratory results: Lumbar puncture reveals albuminocytologic separation in the cerebrospinal fluid, characterized by a significant increase in protein content with only a slight rise in cell count.

Therapies 
Treatment includes plasmapheresis, intravenous immunoglobulin, and supportive treatment such as respiratory assistance till recovery.
Most patients have recovery within weeks to months, whereas 10%-20% are left with enduring disability.

Postinfectious encephalitis may occur after viral infections such as chicken pox, rubella, measles, and mumps, and is identified by temporary, extensive demyelination.
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​Pathology: Charcot-Marie-Tooth Disease
The results stem from a mutation in one of the genes related to nerve myelination and function. Various types of the disease exhibit distinct inheritance patterns and associated mutations.
Typically manifests at age 20, but the age of onset varies depending on the type of sickness.

Pathology 
Manifestation: Peripheral nerves enlargement; spinal cord posterior columns degeneration.
Microscopic findings show a "onion bulb" appearance of nerves due to many episodes of demyelination and remyelination, together with Schwann cell hyperplasia.

Pathophysiology: Mutations cause irregular myelin production, leading to demyelination and reduced nerve conduction speed. Schwann cells proliferate and remyelinate segments affected by demyelination.

The specific presentation varies depending on the particular form of the disease. However, typical symptoms include gradual weakening of the muscles in the limbs furthest from the torso, resulting in conditions such as foot drop, unsteady walking, deteriorating handwriting, and muscular spasms.
The physical examination reveals pes cavus deformity (high arch), "stork leg" deformity (due to calf muscle atrophy), scoliosis, reduced deep tendon reflexes, diminished sensibility to vibration and proprioception, and tremor.

Treatment of neuropathies, corrective surgery for joint abnormalities if necessary, and genetic counseling.

Charcot-Marie-Tooth  disease is the most prevalent hereditary neurological condition.
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Symptoms and Signs of Charcot - Marie- Tooth Disease

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​Pathology - Neoplasms of the Vagina (Clear Cell Carcinoma, Squamous Cell Carcinoma)
​Clear cell adenocarcinoma (CCA) is a rare kind of cancer that typically affects daughters of mothers who were treated with DES during pregnancy. It is commonly detected in individuals between the ages of 15 and 20.

Squamous cell carcinoma (SCC) is an uncommon kind of cancer that is linked to HPV infection.

Pathology 
CCA: Gross: red granular lesion seen on the upper anterior vagina. The cells are vacuolated and contain glycogen. They are preceded by vaginal adenosis, which is characterized by columnar epithelial-lined glands in locations that are typically lined by stratified squamous epithelium.

SCC: Gross finding of an invasive plaque-like mass located in the upper posterior vagina. The process starts with epithelial thickening linked to dysplastic alterations at a microscopic level, which then progresses to invasive squamous cell carcinoma with keratinization.

Clinical Symptoms 
CCA may be asymptomatic and have a gradual onset characterized by vaginal hemorrhage.
SCC may be asymptomatic; can present with irregular spotting, vaginal discharge, vulvar discomfort, and pruritus.


Utilizing surgery and irradiation, together with vigilant monitoring and screening for high-risk individuals.
Sarcoma botryoides is a rare type of polypoidal embryonal rhabdomyosarcoma, and it is the most prevalent sarcoma found in infants under the age of 5. The condition appears as a tumor that looks like a cluster of grapes extending into the vagina and necessitates surgical removal and chemotherapy.
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