What is the diagnosis?

Malignant (necrotizing) external otitis

0 Invasive infection of the external auditory canal and skull base.0 Risk factors: elderly patients with diabetes mellitus. 0 Etiology: Pseudomonas aeruginosa (95% of cases). 0 Clues for dx: exquisite otalgia and otorrhea, which are not responsive to

topical measures used to treat simple external otitis.0 Complications: meningitis, brain abscess, and dural sinus thrombophlebitis.0 Dx: CT, MRI and Gallium SPECT scans are useful for both diagnosis and

follow-up.0 Tx: Ciprofloxacin (antibiotic of choice)

0 Initial treatment with intravenous ciprofloxacin until we obtain a subjective clinical response and/or a decrease in the ESR or CRP.

0 Duration: six to eight weeks is generally recommended, as indicated for osteomyelitis.

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ACD 06-17Learning points

Sowmya Chandra-ReddyPGY2 IM UAMS

Differential diagnosis for osteolytic bone lesions

0 MULTIPLE MYELOMA [purely Osteolytic ]0 METASTATIC CARCINOMA: 80% of primary tumors in patients presenting

with metastatic bone disease:0 Prostate (mainly osteoblastic)0 Breast cancer in females0 Thyroid 0 Lung 0 Kidney 0 Pancreas

0 LANGERHANS HISTIOCYTOSIS- is a rare histiocytic disorder0 Most commonly characterized by single or multiple Osteolytic bone lesions

demonstrating infiltration with histiocytes with "bean-shaped" nuclei on biopsy with or without histiocytic infiltration of extra skeletal lesions ( mostly skin, lungs and central nervous system)

0 Lymphomas

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Carcinoma of unknown Primary(CUPs)

0 CUP is a relatively common clinical entity, accounting for 4 to 5 percent of all invasive cancers

0 Patients typically present with symptoms referable to metastases. 0 The initial work-up, including physical examination, laboratory studies, and imaging

procedures, often fails to identify the primary site.0 Patients are initially placed into one of four categories based upon the light

microscopic examination of the initial biopsy.:1. Adenocarcinoma– 70% of CUPs autopsy series has identified the most were lung, pancreas, hepatobiliary tree and kidney

2. Squamous cell carcinoma- 5% of CUP s

3. Neuroendocrine carcinoma, which may be either well differentiated or poorly differentiated: 1%

4. Poorly differentiated tumors, most of which are recognized as carcinomas by histologic examination.- 20-25%

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Squamous cell carcinoma (SCC)

0 Uncommon in the absence of an obvious primary tumor, except for patients who present with a neck mass.

0 The clinical presentation and subsequent diagnostic evaluation of such patients depends upon the predominant area of the metastasis:0 Upper and midcervical lymphadenopathy —cancer of the head and neck.

0 Further evaluation should include CT of the head and neck, direct laryngoscopy, and nasopharyngoscopy.

0 PET scanning should be performed if a primary site cannot be identified by CT or endoscopy.

0 Inguinal lymphadenopathy — genital or anorectal area. 0 In women, careful examination of the vulva, vagina, and cervix is important. Careful inspection of

the penis should be performed in men. 0 Digital rectal examination and anoscopy should be performed in both sexes.

0 Adenopathy at other sites — Lymphadenopathy at sites other than cervical, supraclavicular, or inguinal nodes usually represents metastasis from a primary lung cancer. 0 These patients should be evaluated with CT of the chest and fiber optic bronchoscopy.0 Immuno-histochemical studies and electron microscopy are of little value in identifying the

primary site for patients with squamous cell carcinoma of unknown primary site

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