Dr. Chen and I sent here some interesting and classical FNA cases here. It seems that people here are not very interested to these cases. I assume that most pathologists here do not  do or sign out FNA cases in your clinical practice.

You have to attend the discussion if you want to learn sth from online. People are more likely to see one photo and give a guess diagnosis especially for Pap smears. I think it will not be very useful.

Anyway I conclude this case in the end of 2008. Happy New Year for every one.

cz

Some facts about paraganglioma:

n      Mostly benign tumors, up to 12% malignant

n      Composed of cells derived from the primitive neural crest

n      Found in different locations;

n      middle ear

n      skull base

n       pelvic floor

n      Others

n      Head and neck area, located near  along the cranial nerves and the arterial vasculature

n      Found commonly in association with the carotid body

n      Rarely seen in :orbit, paranasal sinuses or thyroid

n      Average age 50-60yrs

n      M:F =(1:4)

n      Presentation

n      enlarging masses that are asymptomatic or associated with symptoms of mass effects

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Paraganglioma-Cytomorphology

n      Cellular/bloody

n      Loosely cohesive, epitheloid  and spindle cells

n      Varies from uniform  to pleomorphic

n      Rosettes, Zellballen structures

n      Reddish cytoplasmic granules on DQ

n      Round/oval /spindle nuclei

n      “Salt and pepper chromatin”

n      Intranuclear cytoplasmic inclusions

n      Cytology hardly recommended by surgeons  because of risk of complications:

n      Hemorrhage, damage to carotid body

n      Distinction between benign and malignant CANNOT be made on cytology

n      Require surgical excision with demonstration of metastases and NOT local invasion

Differential Diagnosis

n      Metastatic adenocarcinoma

n      Metastatic sarcoma

n      Metastatic papillary thyroid carcinoma

n      Metastatic medullary thyroid carcinoma

n      Melanoma

Metastatic Adenocarcinoma-Cytomorphology

n      Hypercellular, clusters and isolated cells

n       Gland formation

n      Nuclear  pleomorphism, overlapping nuclei

n      Nuclear hyperchromasia

n      Irregular nuclear membranes

n      Vacuolated cytoplasm

n      IHC: Keratin +

Metastatic Sarcoma-Cytomorphology

n      High grade, spindle cells

n      Nuclear hyperchromasia,

n      Bizarre atypia

n      IHC:  Negative for neuroendocrine markers, +

Metastatic papillary thyroid carcinoma

n      Hypercellular, sheets, papillae, microfollicles

n      Nuclear crowding, powdery chromatin

n      Nuclei grooves, pseudoinclusions, nucleoli

n      Cytoplasm-scant, squamoid, Hurthle-like or vacuolated

n      Psammoma bodies, multinucleated giant cells,

n      IHC: Thyroglobulin, TTF-1 +

Metastatic medullary thyroid carcinoma-Cytomorphology

n      Numerous single cells or loose clusters

n      Epitheloid/plasmacytoid/spindle

n      Round nuclei

n      Fine to coarse chromatin

n      Inconspicuous nucleoli

n      Nuclear pseudoinclusions

n      Binucleation/multinucleation

n      Amyloid

n      IHC: Calcitonin, CEA,TTF-1, Thyroglobulin

Melanoma-Cytomorphology

n      Discohesive atypical cells

n      Binucleation

n      Nuclear grooves

n      Nuclear pseudoinclusions

n      Melanin pigment

n      IHC: Melan A, S-100, HMB-45+

 cqzhao老师做事很认真，上传病例很典型，一般都是不常见的，让我们开阔了眼界。诊断和鉴别诊断都很详细，学到不少知识。再次感谢cqzhao老师。

另外我有一个问题：是不是PAN CK-和TTF-1-才排除小细胞癌的？形态学上考虑不考虑小细胞癌？