Case Of The Month -August 2005

INTERESTING CASE OF MELANOMA WITH UNUSUAL PATTERN

Clinical History

• Female 20 yrs with previous history of melanoma resected 18 months ago, admitted with pancreatitis.
• On C.T. there are abdominal masses, large mediastinal mass, also L) axilla mass and multiple epigastric masses.
• FNA of epigastric mass was performed under U/S.

Image 1 (Low power view)

Image 2 (High power)

Image 3

Image 4- Cell Block

Image 5- HMB-45

Image 6- Melan-A

Cytology:

On site smears are extremely cellular with dissociate and sheets of small malignant cells- devoid of cytoplasm and hyperchromatic nuclei with granular chromatin, irregular nuclear membrane, in places with molding effects. Adequacy of the specimen was confirmed on site smears.

Discussion:

Melanoma is often easily diagnosed in presence of classical features like pleomorphic cells with binucleation. prominent nucleoli, intra nuclear inclusion, melanin pigment etc. The cells seen here represent a poorly differentiated malignant neoplasm. That given the history of melanoma, this is most consistent with a metastatic melanoma. Although the picture is unusual, melanoma can present with any pattern. The main differential diagnosis are Lymphoma, Small cell anaplastic carcinoma, Neuroblastoma, and other small cell malignant tumour.

So to confirm melanoma and to exclude other P.D. small cell type malignant tumour, immunostaining for HMB-45, S100, Melan-A, Vimentin, AE 1 and 3, Synaptophysin, Chromogranin are done. HMB-45, Melan-A, Vimentin are positive and others are negative which confirmed the diagnosis of a metastatic melanoma.

Biopsy of Left axillary mass was done few days after, showed similar picture as seen in cytology of FNA of Epigastric mass.

Thanks to Sarla for submitting this case