Primitive neuroectodermal tumor of the kidney. A report of two cases diagnosed by fine needle aspiration cytology.
BACKGROUND
Primitive neurocetodermal tumors (PNETs) constitute a family of neoplasms of presumed neuroectrodermal origin most often presenting as bone or soft tissue masses. There are very few reported cases of PNET of the kidney and none diagnosed by fine needle aspiration cytology (FNAC), to the best of our knowledge, in the world literature. We present two cases of renal PNET diagnosed on cytology.


METHODS
Two patients with renal masses were diagnosed as having PNET on FNAC. Cytologically the tumors showed a dispersed population of malignant small round cells with focal rosette formation and perivascular arrangement of tumor cells. Immunohistochemistry on the cell blocks in both cases showed strong membrane positivity for CD99 (MIC2). Cytogenetic studies in both cases showed the characteristic t(11;22)(q24;q12) translocation, with additional chromosomal abnormalities in case 2.


CONCLUSIONS
PNET of the kidney is a distinct entity and can be diagnosed on fine needle aspiration smears and confirmed with immunohistochemistry and cytogenetic studies. A diagnosis of PNET must be included in the differential diagnosis of renal masses in adolescents and young adults.
Premalata
Chennagiri S
CS
Cytopathology Unit, Department of Pathology, Kidwai Memorial Institute of Oncology, M. H. Marigowda Road, Bangalore, India 560029. prema_venka@hotmail.com
Gayathri Devi
Muniyappa
M
Biswas
Siddarth
S
Mukherjee
Geethashree
G
Balu
Sadashivan
S
Sundareshan
Tambarahalli S
TS
Prabhakaran
Ponnuswamy S
PS
D000071443:12E7 Antigen; D000328:Adult; D015703:Antigens, CD / Q000032:analysis; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001707:Biopsy, Needle / Q000379:methods*; D015815:Cell Adhesion Molecules / Q000032:analysis; D002880:Chromosomes, Human, Pair 11; D002892:Chromosomes, Human, Pair 22; D020732:Cytogenetic Analysis; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology* / Q000628:therapy; D008297:Male; D009392:Nephrectomy; D018241:Neuroectodermal Tumors, Primitive, Peripheral / Q000737:chemistry / Q000235:genetics / Q000473:pathology* / Q000628:therapy; D014178:Translocation, Genetic
D000071443:12E7 Antigen; D015703:Antigens, CD; D000970:Antineoplastic Agents; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules