1.Sinonasal haemangiopericytoma: histomorphology and differential diagnoses
The Malaysian Journal of Pathology 2015;37(1):53-56
A 39-year-old female presented with a fleshy nasal polyp occluding the left nasal cavity, associated
with haemopurulent discharge. Computed Tomography (CT) and Magnetic Resonance Imaging
(MRI) scans of the paranasal cavities revealed a large polypoid tumour arising from the left
middle turbinate and obstructing the left maxillary sinus ostium. However, no bony or intracranial
involvement was identified. A biopsy revealed a tumour with small blue round cell morphology.
The tumour cells showed diffuse strong membranous CD99 positivity and patchy CD34 positivity.
Ancillary cytogenetic tests for the EWSR1 and SS18/SYT gene translocations were negative. In
view of the non-invasive nature of the tumour and the low cell proliferative index (Ki-67) of 5%,
a medial maxillectomy resection was performed. The resection revealed additional areas with
spindle-cell morphology and focal haemangiopericytic vasculature. The tumour continued to show
immunoreactivity to CD99 and CD34, as well as Smooth Muscle Actin (SMA) and Muscle Specific
Actin (MSA). The overall findings are in keeping with a sinonasal haemangiopericytoma. With clear
surgical resection margins, the patient is on routine follow-up and is currently disease-free.
2.Diagnosing A Rare Case Of Desmoplastic Small Round Cell Tumour On Liver Biopsy
Cheo Fan Foon ; Leow Wei Qiang
The Malaysian Journal of Pathology 2016;38(2):149-152
A 50-year-old male of Indian descent presented with jaundice and right hypochondrium pain.
Following a computed tomography (CT) scan of the abdomen, a segment 7 liver lesion was
visualized, accompanied by extensive peritoneal tumour deposits. An ultrasound guided liver biopsy
was performed and histology showed loose nests and sheets of tumour cells with a small blue round
cell morphology. The tumour cells showed patchy strong immunopositivity for cytokeratins (AE1/3,
CK7, CK19) and synaptophysin, while showing diffuse strong perinuclear positivity for desmin.
Interphase fluorescence in-situ hybridization (FISH) study using EWSR1 breakapart probe was
positive for EWSR1 gene rearrangement.
Desmoplastic small round cell tumour is a rare but aggressive intra-abdominal mesenchymal
tumour. While the primary sites of involvement are usually the peritoneum and omentum, visceral
involvement can occur. We wish to highlight the importance of considering this entity when
evaluating a liver biopsy especially in a less than classical clinical context.
3.A single hepatic mass with two tales: hepatic tuberculosis and hepatocellular carcinoma
Yi De Ian KOH ; Wei-Qiang LEOW
Journal of Liver Cancer 2023;23(2):397-401
Hepatic tuberculosis (HTB) is an uncommon manifestation of tuberculous infections, and there has been no proven causal link between HTB and hepatocellular carcinoma (HCC). We herein present a rare case of a synchronous presentation of HTB and HCC within a single hepatic mass. A 57-year-old Chinese gentleman with recently diagnosed sigmoid adenocarcinoma was found to have a left lower lobe pulmonary nodule and solitary hepatic mass on staging computed tomography. Biopsies showed the hepatic mass to have both HTB and HCC components. This serves as a reminder that HTB is an important differential to consider for space-occupying lesions in the liver. Histological evaluation of suspected hepatic malignancies is recommended to exclude the presence of HTB in appropriate clinical settings.
4.A rare case of combined placental site trophoblastic tumour with mature cystic teratoma and mixed germ cell tumour in the testis
Leow Wei Qiang ; Loh Hwai Liang Alwin ; Lee Lui Shiong ; Goh Chin Hong Ronald
The Malaysian Journal of Pathology 2015;37(2):145-147
A 20-year-old male presented with persistent right testicular pain. Following ultrasound detection
of testicular nodules and biopsy for intraoperative consultation which yielded germ cell tumour, he
underwent radical orchidectomy. A predominantly whitish cyst and a lobulated, variegated nodule
were identified. Histology showed a mature cystic teratoma with a focus of infiltrative epithelioid
cells containing eosinophilic cytoplasm and pleomorphic nuclei, invading ectatic vessel wall
associated with fibrinoid change. These cells were positive for cytokeratin, human placental lactogen
and inhibin, while negative for Melan-A, p63 and alpha-fetoprotein, consistent with placental site
trophoblastic tumor (PSTT). The variegated nodule was a mixed germ cell tumour composed of
embryonal carcinoma and immature teratoma. Aside from choriocarcinoma, primary trophoblastic
tumors such as PSTT, which are derived from intermediate trophoblasts, are extremely rare in the
testis. Aside from a case of pure testicular PSTT, 2 other cases have been described in association
with germ cell tumour, of which one is a mature teratoma with PSTT that demonstrated gain of
chromosome 12p. The other presented with PSTT in retroperitoneal recurrence of a testicular mixed
germ cell tumour. We discussed the features of this tumour in the testis and important differentials
in its diagnosis.
5.Diagnostic conundrum of a perineal tumour: a rectal gastrointestinal stromal tumour mimic
Shi RUOYU ; Chew Min HOE ; Leow Wei QIANG
The Malaysian Journal of Pathology 2017;39(3):293-296
Gastrointestinal stromal tumour (GIST) is a common mesenchymal tumour arising in the gastrointestinaltract, but not frequently encountered in the rectum. Herein, we describe a case of a rectal GISTwhich mimicked histomorphological features of a schwannoma; thus, making intraoperative frozensection evaluation challenging. Although subsequent immunohistochemistry and molecular findingsreadily confirmed the diagnosis of a GIST, we wish to draw attention to three clues that will help thepathologist steer clear of this potential diagnostic pitfall. One, GISTs are relatively more commonthan schwannomas in the rectum. Two, schwannomas usually have very little mitoses. Three,rectal GISTs commonly exhibit nuclear palisades. We also discuss the diagnostic, prognostic andtherapeutic functions of immunohistochemical and molecular investigations. As the surgical intentfor rectal GISTs is for en-bloc excision with wide margins, we surmise that the intraoperative consultshould include GIST as a possible differential diagnosis for rectal mesenchymal tumours. In view ofthe potential for neoadjuvant treatment with imatinib before surgical excision to preserve sphincterfunction, a multidisciplinary approach is recommended for establishing most effective treatmentstrategy in these rare complex cases.
6.Non-alcoholic fatty liver disease: the pathologist’s perspective
Wei-Qiang LEOW ; Anthony Wing-Hung CHAN ; Paulo Giovanni L. MENDOZA ; Regina LO ; Kihan YAP ; Haeryoung KIM
Clinical and Molecular Hepatology 2023;29(Suppl):S302-S318
Non-alcoholic fatty liver disease (NAFLD) is a spectrum of diseases characterized by fatty accumulation in hepatocytes, ranging from steatosis, non-alcoholic steatohepatitis, to cirrhosis. While histopathological evaluation of liver biopsies plays a central role in the diagnosis of NAFLD, limitations such as the problem of interobserver variability still exist and active research is underway to improve the diagnostic utility of liver biopsies. In this article, we provide a comprehensive overview of the histopathological features of NAFLD, the current grading and staging systems, and discuss the present and future roles of liver biopsies in the diagnosis and prognostication of NAFLD.
9.Disseminated peritoneal leiomyomatosis: a devastating sequelae of unconfined laparoscopic morcellation.
Hwee Leong TAN ; Ye Xin KOH ; Min Hoe CHEW ; Junjie WANG ; Jason Shau Khng LIM ; Wei Qiang LEOW ; Ser Yee LEE
Singapore medical journal 2019;60(12):652-654
There has been growing concern surrounding the use of unconfined power morcellation in laparoscopic surgeries for uterine leiomyoma due to its associated risks and long-term clinical sequelae, including parasitic leiomyomas and disseminated peritoneal leiomyomatosis (DPL). We present a case of DPL resulting from previous laparoscopic morcellation and a review of the existing literature. DPL is a potentially devastating consequence of unconfined laparoscopic morcellation in the surgical management of uterine fibroids. A multidisciplinary approach is recommended in the management of DPL, especially in cases of multivisceral involvement. Clinical caution ought to be exercised when using power morcellators; when unavoidable, confined laparoscopic morcellation offers a promising mitigation and should be adopted if practicable.
10.Impact of fatty liver on long-term outcomes in chronic hepatitis B: a systematic review and matched analysis of individual patient data meta-analysis
Yu Jun WONG ; Vy H. NGUYEN ; Hwai-I YANG ; Jie LI ; Michael Huan LE ; Wan-Jung WU ; Nicole Xinrong HAN ; Khi Yung FONG ; Elizebeth CHEN ; Connie WONG ; Fajuan RUI ; Xiaoming XU ; Qi XUE ; Xin Yu HU ; Wei Qiang LEOW ; George Boon-Bee GOH ; Ramsey CHEUNG ; Grace WONG ; Vincent Wai-Sun WONG ; Ming-Whei YU ; Mindie H. NGUYEN
Clinical and Molecular Hepatology 2023;29(3):705-720
Background/Aims:
Chronic hepatitis B (CHB) and fatty liver (FL) often co-exist, but natural history data of this dual condition (CHB-FL) are sparse. Via a systematic review, conventional meta-analysis (MA) and individual patient-level data MA (IPDMA), we compared liver-related outcomes and mortality between CHB-FL and CHB-no FL patients.
Methods:
We searched 4 databases from inception to December 2021 and pooled study-level estimates using a random- effects model for conventional MA. For IPDMA, we evaluated outcomes after balancing the two study groups with inverse probability treatment weighting (IPTW) on age, sex, cirrhosis, diabetes, ALT, HBeAg, HBV DNA, and antiviral treatment.
Results:
We screened 2,157 articles and included 19 eligible studies (17,955 patients: 11,908 CHB-no FL; 6,047 CHB-FL) in conventional MA, which found severe heterogeneity (I2=88–95%) and no significant differences in HCC, cirrhosis, mortality, or HBsAg seroclearance incidence (P=0.27–0.93). IPDMA included 13,262 patients: 8,625 CHB-no FL and 4,637 CHB-FL patients who differed in several characteristics. The IPTW cohort included 6,955 CHB-no FL and 3,346 CHB-FL well-matched patients. CHB-FL patients (vs. CHB-no FL) had significantly lower HCC, cirrhosis, mortality and higher HBsAg seroclearance incidence (all p≤0.002), with consistent results in subgroups. CHB-FL diagnosed by liver biopsy had a higher 10-year cumulative HCC incidence than CHB-FL diagnosed with non-invasive methods (63.6% vs. 4.3%, p<0.0001).
Conclusions
IPDMA data with well-matched CHB patient groups showed that FL (vs. no FL) was associated with significantly lower HCC, cirrhosis, and mortality risk and higher HBsAg seroclearance probability.