Immunohistochemistry

 This is a method is used to detect a specific antigen in the tissue in order to identify the type of disease.

Infections caused by N. meningiditis

1.  Bacteremia without sepsis.  Organism spreads to blood but no major reaction.

2.  Meningococcemia without meningitis.  Fever, headache, petechia, hypotension, disseminated       intravascular coagulation.  The Waterhouse-Friderichsen Syndrome is a rapid, progressive meningococcemia with shock, organ failure, adrenal necrosis, and death.

3.  Meningitis with meningococcemia.  Sudden onset fever, chills, headache, confusion, nuchal rigidity.  This occurs rapidly.

4.  Meningoencephalitis.  Patients are deeply comatose.

Diagnosis made by examining CSF.

Acanthosis nigricans is a pigmented skin lesion commonly present in the axilla which is a phenotypic marker for an insulin-receptor abnormality as well as a marker for adenocarcinoma, most commonly of gastric origin.

Salivary gland pathology

Inflammation 

a. Sialolithiasis produces a secondary inflammatory reaction  to obstruction and the resultant enlargement of ducts by stones. It may be complicated by actual infection with mouth flora. 

b. Sialadenitis is a primary inflammatory reaction, but it is not always infectious. It may be part of an autoimmune disease  (e.g., Sjogren's syndrome), or the result of bacterial or virals (e.g., mumps) infection. 

Sjögren’s syndrome

a. An autoimmune disease of the salivary and lacrimal glands.
b. Autonuclear antibodies (ANAs) against salivary ducts may be seen.
c. Triad of symptoms include:
(1) Xerostomia—from decreased saliva production.
(2) Keratoconjunctivitis sicca (dry eyes)—from decreased tear production.
(3) Rheumatoid arthritis.
(4) Enlargement of the salivary or lacrimal glands, known as Mikulicz syndrome, may also be observed. 

d. Histologically, a dense infiltration of the gland by lymphocytes is observed.

Tumors

The parotid gland accounts for more than three-quarters of these tumors, most of which are benign. Of the remainder, more occur in the submandibular gland than in the sublingual, and most of these are malignant. Many are surgically, cured, but local recurrence is common. 

a. Pleomorphic adenoma is generally benign and accounts for approximately three-quarters of all salivary gland tumors. If  is composed of multiple epithelial and mesenchymal cell types. Complications may arise due to involvement of cranial nerve VII. 

(a) The most common salivary gland tumor.
(b) Is benign.
(c) Prognosis is good after proper surgical excision.

b. Warthin's tumor (adenolymphoma) is also benign, occuring almost exclusively in the parotid gland. It is grossly cystic.

Microscopic examination reveals cell types suggestive of branchial cleft origin embedded in a lymphoid matrix. 

c. Mucoepidermoid tumors also occur primarily in the parotid and have a high rate of malignant transformation.The malignant component is usually squamous cell.  Prognosis of tumor depends on grade and stage of disease.

d. Cylindroma (adenoid cysticc. Mucoepidermoid tumors carcinoma) is more common in the minor salivary glands found in the oral mucosa, and metastases are more common than in other tumors of the salivary glands. Facial nerve complications are frequent. 
(1) Grossly, the tumor forms multiple lobules surrounded by a capsule. 
(2) Microscopically, small cells form glands containin mucoid material 

Infections caused by gonorrhea

1.  Acute urethritis.  Mostly in males.  Generally self-limiting.  Dysuria and purulent discharge.

2.  Endocervical infection.  Purulent vaginal discharge, abnormal menses, pelvic pain.  Often co-infection with other STD’s.  Some women are asymptomatic.

3.  Pelvic Inflammatory Disease (PID).  Consequence of ascending endocervical infection.  Causes salpingitis, endometriosis, bilateral abdominal pain, discharge, fever.  May lead to sterility, chronic pain, and ectopic pregnancy because of loss of fallopian cilia.

4.  Anorectal inflammation.  Mostly in homosexual men.  Pain, itching, discharge from anus.

5.  Dermatitis/arthritis.  Occurs after bacteremia.  Skin will have papules on an erythematous base which develop into necrotic pustules.  Asymmetric joint pain.  These infections are susceptible to penicillin.

6.  Neonatal infections.  Ophthalmia neonatorum is a conjunctival infection from going through infected vagina.  After one year of age, suspect child abuse.

Urinary tract infection
Most often caused by gram-negative, rod-shaped bacteria that are normal residents of the enteric tract, especially Escherichia coli.

Clinical manifestations: 

frequent urination, dysuria, pyuria (increased PMNs), hematuria, and bacteriuria.

May lead to infection of the urinary bladder (cystitis) or kidney (pyelonephritis).