NQ-007
Answer:
(A) Astrocytoma
Pathology of the case:
The cytologic smear on low magnification
shows a network of cells that appears like a fish net. On higher magnification,
the tumor is composed of elongated nuclei with pointed ends reminiscent of a
baking potato. Most of the cells have coarse chromatin and with distinct
nucleoli. There is also a good variation of nuclear size and shape. On the
background, there are elongated cytoplasmic processes (arrow) reminiscent of
dripping honey or syrup. There is also a bluish mucoid background. These are
features of a smear from a glioma such as astrocytoma but oligodendroglioma and
glioblastoma can also give this type of pattern.
Pleomorphic
xanthoastrocytoma: There are no pleomorphic cells or xanthomatous cells here
to suggest this diagnosis. However, one must know that the distribution of
pleomorphic and xanthomatous cells in a pleomorphic xanthoastrocytoma can be
rather uneven and a thorough search is important
Metastatic melanoma and metastatic carcinoma: Metastatic melanoma can take many shapes and some of them may even have a plasmacytoid pattern. In general, the major differential diagnosis of metastatic melanoma is metastatic carcinoma as both of them share the features of large atypical cells with high nuclear to cytoplasmic ratio, large nuclei and prominent nucleoli. Barring from the presence of melanin pigment in melanoma that would help to make the diagnosis, the two of them may not be always separated on smear. Most metastatic melanomas tend to be amelanotic or have very little pigment. However, frozen sections of metastatic adenocarcinoma and squamous carcinoma may give a histologic pattern that helps to separate the two.
Meningioma:
On cytologic preparations, meningiomas typically have a good amount of
cytoplasm, oval and rather monotonous nuclei and sometimes cellular whorls.
Typically, some tumor cells will form small clusters or sheets but scattered
individual cells are also present. These scattered single cells often have the
shape of a piece of veil being blown in the wind. One must have some imagination
in order to appreciate this feature.