Winter Meeting 2011 - The Pathological Society of Great Britain ...

P61
Waldenströms Macroglobulinaemia – A rare Cause of
Obstructive Nephropathy
P NK Schneider; M Taylor
Royal Sussex County Hospital, Brighton, United Kingdom
Case
We report a 78 year old man with a history of stable Waldenströms Macroglobulinaemia
(also known as lymphoplasmacytic lymphoma) who presented with obstructive uropathy
secondary to a retroperitoneal mass which extrinsically compressed both ureters.
The CT findings resulted in significant diagnostic uncertainty. The differential diagnoses
considered included retroperitoneal fibrosis, lymphoma and metastatic malignancy.
Post mortem examination revealed localised retroperitoneal amyloidosis which proved
on immunohistochemistry to label positive for anti-IgM antibody consistent with the
deposition secondary to Waldenströms Macroglobulinaemia.
Discussion
Amyloidosis, resulting from IgM paraprotein deposition, is a rare complication of
Waldenströms Macroglobulinaemia and poses an adverse survival factor. It can be seen in
a wide variety of patterns and locations throughout the body; retroperitoneal involvement
however, is infrequent and has to our knowledge not been reported before.
Since early diagnosis is the key for effective treatment and prevention of complications
we would like to emphasis that localised retroperitoneal amyloidosis should be added to
the list of causes of ureteric obstruction especially in the background of Waldenströms
Macroglobulinaemia.
P63
Lipoprotein Lipase is a Candidate Oncogene in Cervical
Squamous Cell Carcinoma
P SA Carter; NA Foster; I Roberts; MR Pett; N Coleman
Medical Research Council Cancer Cell Unit, Cambridge, United Kingdom
Host genomic abnormalities that drive progression of cervical squamous cell carcinoma
(SCC) remain poorly understood. In a systematic molecular cytogenetic analysis
of cervical carcinoma cells, we identified a novel reciprocal translocation, t(8:12)
(p21.3:p13.31), present in 100% of metaphases of the SCC cell line MS751. We undertook
detailed mapping of the chromosomal breakpoints using tiling BAC metaphase-FISH
and fosmid fibre-FISH, followed by long-range PCR and sequencing across the fusions.
We identified that the rearrangement involved lipoprotein lipase (LPL) on chromosome
8 and peroxisome biogenesis factor 5 (PEX5) on chromosome 12, resulting in two novel
fusion genes. Whereas LPL-PEX5 was expressed at low levels and contained a premature
stop codon, PEX5-LPL was highly expressed and encoded a full length chimeric protein
(including the majority of the LPL coding region) that most likely drove selection of the
translocation. Consistent with these findings, reverse transcription PCR (RTPCR) showed
that PEX5 was constitutively expressed in normal cervical squamous cells, whereas LPL
expression was negligible. In a tissue microarray, LPL rearrangement was seen in only
1/151 cervical SCCs using interphase FISH. However, over-expression of wild type LPL
was common, being detected by quantitative RTPCR in 14/38 tissue samples and cell
lines. Forced over-expression of both wild type LPL and the PEX5-LPL fusion gene
resulted in increased motility and invasiveness in cervical SCC cells, attributable to the
C terminal non-catalytic domain of LPL, which was retained in the fusion gene. We
conclude that over-expressed wild type or translocated LPL may serve as an oncogene in
cervical SCC and thereby represent a novel candidate for targeted therapy.
P62
Diffuse p63 Positivity in Prostate Cancer: A Case Report
P P Rao 1 ; M Dwyer 2 ; J Mikel 2 ; M Varma 1
1 University Hospital of Wales, Cardiff, United Kingdom;
2 Dorset County Hospital, Dorset, United Kingdom
Prostatic atrophy can closely mimic atrophic pattern of prostate cancer due to the
combination of a pseudoinfiltrative architecture and abnormal cytology with prominent
nucleoli in the basal cells. In morphologically equivocal cases, immunohistochemistry
using antibodies to basal cell markers, high molecular weight cytokeratin (HMWCK)
and p63 is widely used to aid in the distinction. The presence of basal cell marker
immunoreactivity in the suspect glands would strongly suggest a benign diagnosis. We
describe a case of atrophic prostate cancer that showed diffuse p63 immunoreactivity
in the malignant glands. The prostate needle biopsy showed a 4mm focus composed
of small irregular atrophic acini with scant cytoplasm and macronucleoli, infiltrating
between morphologically benign glands. On immunostaining, the atypical glands were
diffusely p63 positive with a non-basal cell cell distribution. No immunoreactivity was
seen in the suspect glands for HMWCK CK5. Despite the p63 positivity a diagnosis of
prostatic adenocarcinoma was made in view of the distinctive morphology and HMWCK
immunonegativity. Subsequent radical prostatectomy revealed prostatic adenocarcinoma,
which in some areas showed diffuse p63 positivity. Diffuse p63 immunoreactivity in
prostate cancer is very rare and only a single series of such cases has been reported to date.
However, awareness of this phenomenon is important to avoid misdiagnosing prostate
cancer as benign. It is noteworthy that 19 of the 21 cancers in the published series showed
an atrophic appearance as in the current case. Misdiagnosis can be avoided by using
p63 in conjunction with a HMWCK antibody such as CK5, CK5/6 or 34betaE12 either
individually or as a cocktail and recognising the non-basal cell distribution the pattern of
p63 immunoreactivity in these rare cancers.
P64
Primary Pseudomyxoma Peritoneii in Benign Ovarian Lesions
P M Samaila 1 ; K Abdullahi 2 ; AG Adesiyun 3
1 Department of Pathology/Morbid Anatomy, Nigeria; 2 Department of
Pathology/ Morbid Anatomy, Ahmadu Bello University Teaching Hospital,
Shika-Zaria, Nigeria; 3 Department of Obstetrics & Gynaecology, Ahmadu
Bello University Teaching Hospital, Shika-Zaria, Nigeria
Background: Psuedomyxoma peritonei is an uncommon fatal disease often associated
with primary appendiceal or gastrointestinal tumour. It is characterised by accumulation
of gelatinous material in the pelvis and abdominal cavity and mainly affects elderly
females with a mean age of 58years at presentation.
Cases: We report two cases of pseudomyxoma ovarii with mucinous cystadenoma. Two
females aged 25years and 42years with clinical diagnosis of advanced ovarian carcinoma
presented respectively with a year and 5years history of abdominal pain, swelling and
mass, menstrual irregularity and weight loss. Exploratory laparotomy revealed unilateral
multi-lobulated ovarian masses, mucinous peritoneal and omental deposits. There were no
obvious appendiceal and gastrointestinal lesions. Both had oophrectomy and peritoneal
clearance of the mucinous deposits. Grossly, the excised lesions showed papillary
multi-locular cystic masses containing gelatinous fluid. The tissues were processed in
paraffin wax and stained with haematoxylin & eosin, periodic acid Schiff, diastase and
mucicarmine. Histology revealed thin strips of ovarian stoma overlying numerous cystic
cavities containing mucin and lined by epithelial cells with intracellular mucin.
Conclusion: The diagnosis of pseudomyxoma peritonei is often incidental and there are
no specific clinical symptoms to aid diagnosis. Mucinous ovarian cystadenocarcinoma
may be associated with pseudomyxoma peritonei with or without appendiceal or
gastrointestinal malignancy. However, neither of the two presented cases had malignant
focus and were categorized as disseminated peritoneal adenomucinosis which is
characterized by abundant extracellular mucin and scanty mucinous epithelium with little
atypia or mitotic activity. Pseudomyxoma may occur in younger females in association
with primary benign ovarian neoplasm.
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