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4. Necrotising fasciitis in the northern territory of australia
ABSTRACTS
1. ANGIOFIBROMA OF SOFT TISSUE: 2 CASE REPORTS 1,2
1
3
4
C. Adhikari , A. Mahar , N. Singh , P. Stalley , M. Wilsher2 and F. Bonar2 1Department of Anatomical Pathology, Royal Prince Alfred Hospital, Camperdown, NSW, 2Douglass Hanly Moir Pathology, Macquarie Park, NSW, 3Department of Cytogenetics, PaLMS, Royal North Shore Hospital, and 4Department of Orthopaedics, RPAH, Camperdown, NSW, Australia Angiofibroma of soft tissue is a distinct benign tumour with fibroblastic morphology and a prominent vascular network which was first described in 2012 in a series of 37 cases.The morphological hallmark is marked by a proliferation of uniform, bland spindle cells and complex vascular pattern within a variably myxoid to collagenous stroma. It is also cytogenetically characterised by t(5;8) translocation and AHRR-NCOA2 gene rearrangement. It has a low rate of local recurrence and no evidence of metastasis following surgical excision. We report two similar cases of this condition one of which had t(5;8) translocation. Being a newly described entity it is important to identify this tumour from other differential diagnosis like cellular angiofibroma, low-grade myxofibrosarcoma, low-grade fibromyxoid sarcoma, solitary fibrous tumour and myxoid liposarcoma depending on the clinical context to avoid any misdiagnosis. 2. BILATERAL MULTIPLE NODULES IN LUNG: EPSTEIN BARR VIRUS ASSOCIATED SMOOTH MUSCLE LESIONS Hakan Aydin and Issam Al Jajeh Singapore General Hospital, Histopathology Section, Department of Pathology, Singapore Background: Presence of multiple nodules in lung is concerning for metastatic tumour and triggers prompt evaluation. Such scenario in a transplant/immunocomprimsed patient is further complicated since infectious aetiology and secondary malignancy need to be considered. Epstein–Barr Virus (EBV) associated smooth muscle tumours are rare lesions that occur in immunocomprimsed patients. They are typically well-differentiated with low mitotic activity and little cytological atypia. They are believed to represent consequence of multiple infection events rather than metastasis. Methods: We report a 51-year-old patient with a history renal transplant and immunosuppression whose surveillance showed multiple bilateral lung nodules. Transthoracic, CT guided fine needle aspiration smears and core biopsy materials were evaluated using light microscopy, immunohistochemistry and in situ hybridisation for EBV associated RNA. Results: The fine needle aspiration smears showed rare, inconclusive stromal pieces. The core biopsy samples displayed spindle cell lesion with smooth-muscle features. There was mild cytological atypia without necrosis or mitotic activity. Immunohistochemical stains showed spindle cells were positive for SMA (smooth muscle actin), desmin, and vimentin. S-100 and MNF116 (cytokeratin stain) were negative. In situ hybridisation for EBER showed nuclear positivity. Conclusions: EBV associated smooth muscle tumours can present as multiple bilateral lung nodules mimicking metastatic tumour. Histologically, they show spindle cell lesion with bland cytological features and low mitotic activity. Supportive ancillary findings by immunohistochemistry and in situ hybridization are as follows: (1)
S107
positive for SMA, desmin and vimentin, (2) negative for S-100 and epithelial marker MNF-116, and (3) positive for EBER. Reference 1. Deyrup AT, Lee VK, Hill CE, et al. EBV associated smooth muscle tumours are distinctive mesenchymal tumours reflecting multiple infection events: a clinicopathologic and molecular analysis of 29 tumours from 19 patients. Am J Surg Pathol 2006; 30: 75–82.
3. CLEAR CELL ADENOCARCINOMA OF URINARY TRACT: 2 CASES INVOLVING URETHRA AND BLADDER Hakan Aydin and Puay Hoon Tan Singapore General Hospital, Histopathology Section, Department of Pathology, Singapore Background: Adenocarcinoma of urothelial tract is considered primary when conventional urothelial carcinoma component is not identified. Cases with co-existing urothelial carcinoma are regarded as differentiation of urothelial origin. Clear cell adenocarcinoma is a rare variant that needs to be discriminated from primary adenocarcinoma of urinary tract, urothelial carcinoma with glandular differentiation and metastatic tumours. Methods: We report two cases of clear cell adenocarcinoma of urinary tract, involving urethra (Case 1) and urinary bladder (Case 2). Histological features, immunohistochemical profile and clinical outcome are summarised. Results: Case 1 (urethral tumour): A 64-year-old Chinese female presented with anterior vaginal wall mass. Biopsy showed clear cell adenocarcinoma and she underwent neoadjuvant chemotherapy. Resection showed urethral tumour involving bladder neck and one lymph node. Histologically, tumour showed tubulopapillary and glandular architecture, hobnail nuclei and clear cytoplasm. Immunohistochemically, tumour cells were CK7 and CA125 positive, thrombomodulin and HMWCK weak positive, and CK20 and p63 negative. Patient is under follow-up. Case 2 (bladder tumour): A 56-year-old Chinese female underwent surgery for bladder mass. Tumour showed tubulopapillary and glandular architecture, hobnail nuclei and clear cytoplasm. Two lymph nodes were positive. Immunohistochemical profile was CK7 positive and CK20 negative. Patient expired following peritoneal carcinomatosis. Conclusions: Clear cell adenocarcinoma of urinary tract can be identified by a constellation of features: (1) presence of tubulopapillary/glandular architecture, high grade hobnail nuclei and clear cytoplasm, (2) absence of primary adenocarcinoma of urinary tract, conventional urothelial carcinoma with glandular differentiation and metastasis, and (3) immunohistochemical profile of positive CK7 and CA125, weak positive HMWCK and CK5/6, negative CK20 and p63 and negative staining for potential metastatic tumour (e.g., CDX2 negative). Clinical behaviour is aggressive. Correct identification can aid in trial of neoadjuvant chemotherapy. Reference 1. Oliva E, Young RH. Clear cell adenocarcinoma of the urethra: a clinicopathologic analysis of 19 cases. Mod Pathol 1996; 9: 513–20.
4. NECROTISING FASCIITIS IN THE NORTHERN TERRITORY OF AUSTRALIA Teresa Bailey, Marina Mileva and Ibrahim Zardawi Royal Darwin Hospital, Northern Territory, Australia
Copyright © Royal College of pathologists of Australasia. Unauthorized reproduction of this article is prohibited.
S108
PATHOLOGY 2014 ABSTRACT SUPPLEMENT
Background: Necrotising fasciitis is a severe, rapidly destructive soft tissue infection characterised by widespread fascial necrosis. Its estimated incidence is 3.5 cases per 100,000 persons, with a case-fatality rate of 24%. Traditional microbiological classification includes polymicrobial infections involving anaerobic bacteria and non-serogroup A streptococci (Type I), and Streptococcus pyogenes with or without Staphylococcus species (Type II). Aims: To determine the morphological and microbiological characteristics of necrotising fasciitis in the Northern Territory. Methods: In the Northern Territory between January 2000 and December 2012 there were 84 cases of necrotising fasciitis. Histological diagnosis was made according to the presence of necrosis of the superficial fascia, with or without neutrophilic infiltrates or bacteria, and oedema of the reticular dermis, subcutaneous fat and superficial fascia. Patient demographics and microbiological results were collated. Results and conclusions: The average age of patients with necrotising fasciitis was 48.9 years. There was a male predominance, and Indigenous patients accounted for 49% of cases. Sites affected, in descending frequency, were lower limbs, upper limbs and torso, head/neck and scrotum/perineum. Despite prompt antimicrobial therapy and surgical intervention, 10% of patients required limb amputation and 25% of patients died from their disease, with almost half being Indigenous. Tissue reaction patterns were similar to those described in the literature, initially involving the superficial fascia followed by extension to both superficial and deep structures with disease progression. Interestingly, our data highlights deviation from the traditional microbiological classification. We demonstrated a high prevalence of pure growths of Staphylococcus (20%) and Pseudomonas (4.7%). Remarkably, fungal isolates were also relatively prevalent. Our findings confirm necrotising fasciitis is a devastating infection associated with high morbidity and mortality. Despite morphological similarities of necrotising fasciitis, data from the Northern Territory portrays unique microbiological variation in its causative organisms.
5. DIVERTICULAR DISEASE, COMPLICATIONS RE-VISITED Showan Balta, Jespal Gill and Reena Ramsaroop Dorevitch Pathology/Ballarat Health Services, Vic, Australia Introduction: Filiform polyposis of the colon is an uncommon entity occasionally encountered in patients with inflammatory bowel disease, characterised by multiple worm-like mucosal projections consisting of sub-mucosal cores lined by normal mucosa. Case study: A 60-year-old man presented with signs and symptoms of large bowel obstruction for 7 days. The patient had a CT scan of the abdomen that showed thickening of the sigmoid wall with suspicion of malignancy. Subsequent colonoscopy showed an exophytictumour extending over 5 cm of the distal sigmoid. The biopsy showed only mucosal ulceration with no evidence of malignancy. The patient then underwent anterior resection of the sigmoid colon. The sigmoid colon was carpeted by numerous finger like projections. On histology this showed mucosal prolapse as a result of extensive diverticular disease. Discussion: We discuss the unusual clinical presentation and gross findings of colonic polyposis related to diverticular disease. Only three similar cases have been reported in the English literature since 2010.
Pathology (2014), 46(S1)
6. EXTRAGENITAL PRIMARY MALIGNANT MIXED MULLERIAN TUMOUR – A CASE PRESENTATION J. Bennett and S. Nigam Pathology Queensland – Gold Coast Hospital Laboratory, Qld, Australia Background: Malignant mixed mullerian tumour (MMMT) is an uncommon, often aggressive malignancy of the female reproductive system, typically arising from the uterus. Histologically, this neoplasm exhibits a biphasic tissue pattern with sarcomatous and carcinomatous elements. Whilst this tumour is known to metastasise outside of the reproductive tract, case reports of its occurrence as an extragenital primary malignancy are exceedingly rare. Case: The following case was seen in 2013 at the Gold Coast Hospital, Queensland. A 67-year-old woman presented to the surgical outpatient clinic complaining of several months of increasing abdominal discomfort. She reported a past history of ER/PR negative breast cancer, which was treated with surgery (unilateral mastectomy) and chemotherapy. She had also undergone a total hysterectomy and bilateral salpingo-oophorectomy many years earlier for abnormal per-vaginal bleeding. After further investigation, she was found to have a large intraabdominal mass within her right iliac fossa, adhered to the anterior abdominal wall. The 2319 cm mass was surgically removed. Macroscopic examination revealed a blood-filled cystic lesion with a thickened wall and necrotic internal lining. Microscopic examination showed predominantly sarcomatous tissue composed of spindle cells, with interspersed nests and trabeculae of malignant epithelial cells, together suggestive of carcinosarcoma. Further immunohistochemical staining confirmed this diagnosis. Discussion: Given this woman’s history of a hysterectomy and bilateral salpingo-oophorectomy more than 30 years prior to this presentation, the favoured diagnosis was an extragenital primary MMMT (as opposed to metastatic disease), potentially arising from pre-existing endometriosis, or from mullerian remnants. There are very few case reports of this particular diagnosis, and as such the subsequent paucity of effective treatment options means this malignancy continues to carry an overall poor prognosis.
7. THE GRENZ ZONE IN DERMATOFIBROMA – AN INCONSISTENT TRUTH. A HISTOPATHOLOGICAL STUDY OF 86 CASES J. F. Cernelc, N. T. Harvey and B. A. Wood Division of Tissue Pathology, PathWest Laboratory Medicine, Sir Charles Gairdner Hospital and Faculty of Pathology and Laboratory Medicine, the University of Western Australia, WA, Australia Background: Dermatofibroma is a benign dermal fibrohistocytic lesion with a number of typical diagnostic features, including the presence of an uninvolved zone of the papillary dermis, referred to as a grenz zone. We identified a number of cases in consultation practice in which the absence of a grenz zone led the pathologist to question the diagnosis of dermatofibroma in otherwise typical cases. Aim: To examine the frequency of the presence of a grenz zone in dermatofibroma and to explore the extent to which the presence of this feature can be explained by ‘off-centre’ sectioning of a spheroid proliferation.
Copyright © Royal College of pathologists of Australasia. Unauthorized reproduction of this article is prohibited.
1. ANGIOFIBROMA OF SOFT TISSUE: 2 CASE REPORTS 1,2
1
3
4
C. Adhikari , A. Mahar , N. Singh , P. Stalley , M. Wilsher2 and F. Bonar2 1Department of Anatomical Pathology, Royal Prince Alfred Hospital, Camperdown, NSW, 2Douglass Hanly Moir Pathology, Macquarie Park, NSW, 3Department of Cytogenetics, PaLMS, Royal North Shore Hospital, and 4Department of Orthopaedics, RPAH, Camperdown, NSW, Australia Angiofibroma of soft tissue is a distinct benign tumour with fibroblastic morphology and a prominent vascular network which was first described in 2012 in a series of 37 cases.The morphological hallmark is marked by a proliferation of uniform, bland spindle cells and complex vascular pattern within a variably myxoid to collagenous stroma. It is also cytogenetically characterised by t(5;8) translocation and AHRR-NCOA2 gene rearrangement. It has a low rate of local recurrence and no evidence of metastasis following surgical excision. We report two similar cases of this condition one of which had t(5;8) translocation. Being a newly described entity it is important to identify this tumour from other differential diagnosis like cellular angiofibroma, low-grade myxofibrosarcoma, low-grade fibromyxoid sarcoma, solitary fibrous tumour and myxoid liposarcoma depending on the clinical context to avoid any misdiagnosis. 2. BILATERAL MULTIPLE NODULES IN LUNG: EPSTEIN BARR VIRUS ASSOCIATED SMOOTH MUSCLE LESIONS Hakan Aydin and Issam Al Jajeh Singapore General Hospital, Histopathology Section, Department of Pathology, Singapore Background: Presence of multiple nodules in lung is concerning for metastatic tumour and triggers prompt evaluation. Such scenario in a transplant/immunocomprimsed patient is further complicated since infectious aetiology and secondary malignancy need to be considered. Epstein–Barr Virus (EBV) associated smooth muscle tumours are rare lesions that occur in immunocomprimsed patients. They are typically well-differentiated with low mitotic activity and little cytological atypia. They are believed to represent consequence of multiple infection events rather than metastasis. Methods: We report a 51-year-old patient with a history renal transplant and immunosuppression whose surveillance showed multiple bilateral lung nodules. Transthoracic, CT guided fine needle aspiration smears and core biopsy materials were evaluated using light microscopy, immunohistochemistry and in situ hybridisation for EBV associated RNA. Results: The fine needle aspiration smears showed rare, inconclusive stromal pieces. The core biopsy samples displayed spindle cell lesion with smooth-muscle features. There was mild cytological atypia without necrosis or mitotic activity. Immunohistochemical stains showed spindle cells were positive for SMA (smooth muscle actin), desmin, and vimentin. S-100 and MNF116 (cytokeratin stain) were negative. In situ hybridisation for EBER showed nuclear positivity. Conclusions: EBV associated smooth muscle tumours can present as multiple bilateral lung nodules mimicking metastatic tumour. Histologically, they show spindle cell lesion with bland cytological features and low mitotic activity. Supportive ancillary findings by immunohistochemistry and in situ hybridization are as follows: (1)
S107
positive for SMA, desmin and vimentin, (2) negative for S-100 and epithelial marker MNF-116, and (3) positive for EBER. Reference 1. Deyrup AT, Lee VK, Hill CE, et al. EBV associated smooth muscle tumours are distinctive mesenchymal tumours reflecting multiple infection events: a clinicopathologic and molecular analysis of 29 tumours from 19 patients. Am J Surg Pathol 2006; 30: 75–82.
3. CLEAR CELL ADENOCARCINOMA OF URINARY TRACT: 2 CASES INVOLVING URETHRA AND BLADDER Hakan Aydin and Puay Hoon Tan Singapore General Hospital, Histopathology Section, Department of Pathology, Singapore Background: Adenocarcinoma of urothelial tract is considered primary when conventional urothelial carcinoma component is not identified. Cases with co-existing urothelial carcinoma are regarded as differentiation of urothelial origin. Clear cell adenocarcinoma is a rare variant that needs to be discriminated from primary adenocarcinoma of urinary tract, urothelial carcinoma with glandular differentiation and metastatic tumours. Methods: We report two cases of clear cell adenocarcinoma of urinary tract, involving urethra (Case 1) and urinary bladder (Case 2). Histological features, immunohistochemical profile and clinical outcome are summarised. Results: Case 1 (urethral tumour): A 64-year-old Chinese female presented with anterior vaginal wall mass. Biopsy showed clear cell adenocarcinoma and she underwent neoadjuvant chemotherapy. Resection showed urethral tumour involving bladder neck and one lymph node. Histologically, tumour showed tubulopapillary and glandular architecture, hobnail nuclei and clear cytoplasm. Immunohistochemically, tumour cells were CK7 and CA125 positive, thrombomodulin and HMWCK weak positive, and CK20 and p63 negative. Patient is under follow-up. Case 2 (bladder tumour): A 56-year-old Chinese female underwent surgery for bladder mass. Tumour showed tubulopapillary and glandular architecture, hobnail nuclei and clear cytoplasm. Two lymph nodes were positive. Immunohistochemical profile was CK7 positive and CK20 negative. Patient expired following peritoneal carcinomatosis. Conclusions: Clear cell adenocarcinoma of urinary tract can be identified by a constellation of features: (1) presence of tubulopapillary/glandular architecture, high grade hobnail nuclei and clear cytoplasm, (2) absence of primary adenocarcinoma of urinary tract, conventional urothelial carcinoma with glandular differentiation and metastasis, and (3) immunohistochemical profile of positive CK7 and CA125, weak positive HMWCK and CK5/6, negative CK20 and p63 and negative staining for potential metastatic tumour (e.g., CDX2 negative). Clinical behaviour is aggressive. Correct identification can aid in trial of neoadjuvant chemotherapy. Reference 1. Oliva E, Young RH. Clear cell adenocarcinoma of the urethra: a clinicopathologic analysis of 19 cases. Mod Pathol 1996; 9: 513–20.
4. NECROTISING FASCIITIS IN THE NORTHERN TERRITORY OF AUSTRALIA Teresa Bailey, Marina Mileva and Ibrahim Zardawi Royal Darwin Hospital, Northern Territory, Australia
Copyright © Royal College of pathologists of Australasia. Unauthorized reproduction of this article is prohibited.
S108
PATHOLOGY 2014 ABSTRACT SUPPLEMENT
Background: Necrotising fasciitis is a severe, rapidly destructive soft tissue infection characterised by widespread fascial necrosis. Its estimated incidence is 3.5 cases per 100,000 persons, with a case-fatality rate of 24%. Traditional microbiological classification includes polymicrobial infections involving anaerobic bacteria and non-serogroup A streptococci (Type I), and Streptococcus pyogenes with or without Staphylococcus species (Type II). Aims: To determine the morphological and microbiological characteristics of necrotising fasciitis in the Northern Territory. Methods: In the Northern Territory between January 2000 and December 2012 there were 84 cases of necrotising fasciitis. Histological diagnosis was made according to the presence of necrosis of the superficial fascia, with or without neutrophilic infiltrates or bacteria, and oedema of the reticular dermis, subcutaneous fat and superficial fascia. Patient demographics and microbiological results were collated. Results and conclusions: The average age of patients with necrotising fasciitis was 48.9 years. There was a male predominance, and Indigenous patients accounted for 49% of cases. Sites affected, in descending frequency, were lower limbs, upper limbs and torso, head/neck and scrotum/perineum. Despite prompt antimicrobial therapy and surgical intervention, 10% of patients required limb amputation and 25% of patients died from their disease, with almost half being Indigenous. Tissue reaction patterns were similar to those described in the literature, initially involving the superficial fascia followed by extension to both superficial and deep structures with disease progression. Interestingly, our data highlights deviation from the traditional microbiological classification. We demonstrated a high prevalence of pure growths of Staphylococcus (20%) and Pseudomonas (4.7%). Remarkably, fungal isolates were also relatively prevalent. Our findings confirm necrotising fasciitis is a devastating infection associated with high morbidity and mortality. Despite morphological similarities of necrotising fasciitis, data from the Northern Territory portrays unique microbiological variation in its causative organisms.
5. DIVERTICULAR DISEASE, COMPLICATIONS RE-VISITED Showan Balta, Jespal Gill and Reena Ramsaroop Dorevitch Pathology/Ballarat Health Services, Vic, Australia Introduction: Filiform polyposis of the colon is an uncommon entity occasionally encountered in patients with inflammatory bowel disease, characterised by multiple worm-like mucosal projections consisting of sub-mucosal cores lined by normal mucosa. Case study: A 60-year-old man presented with signs and symptoms of large bowel obstruction for 7 days. The patient had a CT scan of the abdomen that showed thickening of the sigmoid wall with suspicion of malignancy. Subsequent colonoscopy showed an exophytictumour extending over 5 cm of the distal sigmoid. The biopsy showed only mucosal ulceration with no evidence of malignancy. The patient then underwent anterior resection of the sigmoid colon. The sigmoid colon was carpeted by numerous finger like projections. On histology this showed mucosal prolapse as a result of extensive diverticular disease. Discussion: We discuss the unusual clinical presentation and gross findings of colonic polyposis related to diverticular disease. Only three similar cases have been reported in the English literature since 2010.
Pathology (2014), 46(S1)
6. EXTRAGENITAL PRIMARY MALIGNANT MIXED MULLERIAN TUMOUR – A CASE PRESENTATION J. Bennett and S. Nigam Pathology Queensland – Gold Coast Hospital Laboratory, Qld, Australia Background: Malignant mixed mullerian tumour (MMMT) is an uncommon, often aggressive malignancy of the female reproductive system, typically arising from the uterus. Histologically, this neoplasm exhibits a biphasic tissue pattern with sarcomatous and carcinomatous elements. Whilst this tumour is known to metastasise outside of the reproductive tract, case reports of its occurrence as an extragenital primary malignancy are exceedingly rare. Case: The following case was seen in 2013 at the Gold Coast Hospital, Queensland. A 67-year-old woman presented to the surgical outpatient clinic complaining of several months of increasing abdominal discomfort. She reported a past history of ER/PR negative breast cancer, which was treated with surgery (unilateral mastectomy) and chemotherapy. She had also undergone a total hysterectomy and bilateral salpingo-oophorectomy many years earlier for abnormal per-vaginal bleeding. After further investigation, she was found to have a large intraabdominal mass within her right iliac fossa, adhered to the anterior abdominal wall. The 2319 cm mass was surgically removed. Macroscopic examination revealed a blood-filled cystic lesion with a thickened wall and necrotic internal lining. Microscopic examination showed predominantly sarcomatous tissue composed of spindle cells, with interspersed nests and trabeculae of malignant epithelial cells, together suggestive of carcinosarcoma. Further immunohistochemical staining confirmed this diagnosis. Discussion: Given this woman’s history of a hysterectomy and bilateral salpingo-oophorectomy more than 30 years prior to this presentation, the favoured diagnosis was an extragenital primary MMMT (as opposed to metastatic disease), potentially arising from pre-existing endometriosis, or from mullerian remnants. There are very few case reports of this particular diagnosis, and as such the subsequent paucity of effective treatment options means this malignancy continues to carry an overall poor prognosis.
7. THE GRENZ ZONE IN DERMATOFIBROMA – AN INCONSISTENT TRUTH. A HISTOPATHOLOGICAL STUDY OF 86 CASES J. F. Cernelc, N. T. Harvey and B. A. Wood Division of Tissue Pathology, PathWest Laboratory Medicine, Sir Charles Gairdner Hospital and Faculty of Pathology and Laboratory Medicine, the University of Western Australia, WA, Australia Background: Dermatofibroma is a benign dermal fibrohistocytic lesion with a number of typical diagnostic features, including the presence of an uninvolved zone of the papillary dermis, referred to as a grenz zone. We identified a number of cases in consultation practice in which the absence of a grenz zone led the pathologist to question the diagnosis of dermatofibroma in otherwise typical cases. Aim: To examine the frequency of the presence of a grenz zone in dermatofibroma and to explore the extent to which the presence of this feature can be explained by ‘off-centre’ sectioning of a spheroid proliferation.
Copyright © Royal College of pathologists of Australasia. Unauthorized reproduction of this article is prohibited.