Cellular angiofibroma is genetically similar to spindle cell lipoma: a case report

Cellular angiofibroma arising in the anorectal region: clinicopathologic and immunohistochemical analysis of five cases

Cellular angiofibroma (CA) is a rare, benign mesenchymal tumor with a predilection to the distal female and male genital tract. Extragenital examples of CA, including anorectal CAs, are exceedingly rare and documented mainly as single case reports. Herein, we analyze the clinicopathological and immunohistochemical features of 5 anorectal CAs. There were 4 males and one female ranging in age from 45 to 70 (median, 58) years at the time of surgery. Tumors arose in the superficial tissues of the anorectal (n = 3) and perianal (n = 2) regions. The tumors were well circumscribed ranging from 2 to 6.7 (median, 5.4) cm. All demonstrated a low to moderately cellular proliferation of cytologically bland spindled cells within a variably dense collagenous and focally myxocollagenous stroma and small- to medium-sized vessels featuring perivascular collagen deposition. Two cases showed degenerative and/or inflammatory changes. All 5 tumors strongly expressed CD34 and androgen receptor proteins, more variably expressed estrogen (n = 5) and progesterone (n = 4) receptor proteins and desmin (n = 3), and focally expressed alpha-smooth muscle actin (n = 3), GATA-3 (n = 2), and p16 (n = 1). Retinoblastoma protein expression was reduced (n = 4) (compared with expression in endothelial cells) or completely lost (n = 1). All patients were treated with simple surgical excision, and the 2 study members with follow-up data showed no evidence of local recurrence over a postoperative follow-up interval of 23 and 73 months. In comparison with conventional genital tract CA, our 5 anorectal CAs occurred mostly in males, were generally less cellular, and appear to follow a similar uneventful clinical course.

Cellular Angiofibroma Presenting as a Subepithelial Rectal Mass

A very rare case of cellular angiofibroma arising from the rectum in a 62-year-old man with a normal colonoscopy 2 years earlier is reported. To our knowledge, this is the first such case reported in the literature. The tumor was transanally excised with clear margins, and the patient had no postoperative complications. It is key to accurately differentiate this lesion from other subepithelial rectal tumors and more aggressive genital soft tissue tumors because clinical management varies. We performed a review of clinical records and pathology as well as an extensive literature review.

Cellular angiofibroma of orbit- a rare tumor at the rarest location

Cellular angiofibroma (CAF) is a rare, site-specific benign tumor of mesenchymal origin, which is exclusive of the genital region except very few reported cases of extragenital CAF. Very recently the first case report of orbital CAF has been published and we are presenting the second documented case of CAF in this unusual location, in a 37-year-old man. Magnetic resonance imaging with T2 weighted image revealed a hyper-intense globular mass in the superomedial extraconal region of the left orbit. Histopathology of the excised mass showed numerous bland spindle cells embedded in wispy collagen, suggesting spindle cell tumor. On immunohistochemistry, the specimen was strongly positive to CD34 but negative to desmin, SMA, S-100, C-kit, ERG, EMG, CD31, and CD63, that further confirmed the diagnosis of CAF. CAF is a rare mesenchymal tumor and to the best of the authors' knowledge, this would be the second documented case of orbital CAF.

Potential Diagnostic Pitfalls in Evaluating Immunohistochemistry for Cervical Myofibroblastomas

Cervicovaginal myofibroblastoma (CVM) is a rare benign mesenchymal tumor of the lower female genital tract that shows chromosomal loss of 13q14 (RB1 gene located in this region). The aim of this study was to investigate the utility of immunohistochemistry (IHC) for desmin, CD34, and Rb in diagnosing CVM. All cervical polyps diagnosed from July 2016 to July 2017 were retrospectively reviewed. Cases showing morphologic myofibroblastic differentiation were evaluated by IHC for desmin, CD34, and Rb. Desmin and CD34 staining was recorded as positive or negative. Rb nuclear staining was graded as follows: 0 (<10%), 1 (10%-25%), 2 (>25%-50%), 3 (>50%-75%), or 4 (>75%). Intact nuclear expression of Rb in endothelial cells served as an internal positive control. IHC was performed on 76 cases with 14 excluded from the final cohort due to poor Rb internal control. A total of 61/62 (98.4%) cases were positive for desmin and CD34 with the following Rb distribution: grade 0 (n=53, 86.9%), grade 1 (n=5, 8.2%), grade 2 (n=2, 3.3%), and grade 3 (n=1, 1.6%). One case negative for desmin and CD34 showed grade 3 Rb staining. Upon rereview of the histology, 7/175 cases (4%) were morphologically and immunohistochemically compatible with CVM (desmin and CD34+ grade 0 Rb staining). CVM is a rare and under-recognized entity (4% of cervical polyps) for which morphology remains the mainstay of diagnosis. IHC reliance serves as a potential diagnostic pitfall as 86.9% of cases showing myofibroblastic differentiation demonstrated the staining pattern of desmin and CD34 positivity and Rb deficiency.

First Glance of Molecular Profile of Atypical Cellular Angiofibroma/Cellular Angiofibroma with Sarcomatous Transformation by Next Generation Sequencing

Cellular angiofibroma is a rare benign mesenchymal neoplasm most commonly occurring in the vulvovaginal region in women and the inguinoscrotal region in men with specific genetic deletion involved in the RB1 gene in chromosome 13q14 region. Atypical cellular angiofibroma and cellular angiofibroma with sarcomatous transformation are recently described variants showing worrisome morphological features and strong, diffuse p16 expression. Nevertheless, the molecular profile of these tumor entities is largely unknown. We carried out a next generation sequencing (NGS) study from six cases of atypical cellular angiofibroma and cellular angiofibroma with sarcomatous transformation. We were able to identify oncogenic TP53 gene mutations (33%) which may contribute to pathogenesis also resulting in p16 overexpression. In addition, RB1 gene alterations generally present were identified. Since it is a recently described and rare entity, the whole molecular signaling pathway is still largely obscured and the analysis of larger cohorts is needed to elucidate this issue.

Cellular angiofibroma in the hypopharynx: A case report

RATIONALE

Cellular angiofibroma is a rare benign mesenchymal tumor which mostly occurs in the superficial soft tissues of the genital region. Occurrence in the head and neck region is extremely rare. To our knowledge, this is the first case of cellular angiofibroma arising in the hypopharynx.

PATIENT'S CONCERNS

A 54-year-old male complained of a mass moving through his throat for 1 month. A tumor was found in the right lateral wall of the pharyngeal at the level of the epiglottis by laryngoscope. Magnetic resonance imaging confirmed the presence of a mass in the right lateral pharyngeal area. A benign tumor was suspected based on the clinical symptoms and imaging findings.

DIAGNOSIS

A supporting laryngoscope was performed under general anesthesia and the lesion was resected. Immunohistochemical analysis revealed cellular angiofibroma.

INTERVENTIONS

The patient underwent surgical excision of the lesion.

OUTCOMES

Thus far, no recurrence has been observed 6 months after excision.

LESSONS

Cellular angiofibroma located in the lateral pharyngeal is rare; however, immunohistochemical staining is helpful for its diagnosis. Treatment is relatively simple and requires local excision and follow-up.

PRRX-NCOA1/2 rearrangement characterizes a distinctive fibroblastic neoplasm

Fibroblastic/myofibroblastic neoplasms represent a broad, and occasionally diagnostically challenging, category of soft tissue neoplasms. A subset of these tumors defy conventional classification. However, with the advent of next-generation sequencing, the identification of disease-defining molecular alterations is gradually improving their subclassification. Following identification of two index cases of a distinctive fibroblastic neoplasm with a fusion gene involving PRRX1 and NCOA1, we performed a retrospective review to further characterize this entity. We identified two additional cases, including one with a fusion between PRRX1 and NCOA2. The average patient age was 38 years, and three patients were female. Two tumors occurred on the neck, and the others involved the groin and thigh. Tumors were centered in the subcutis and ranged from 2.3 to 14.0 cm (average 5.8 cm). Morphologically, they were predominantly hypocellular, with focal hypercellularity. They were composed of monomorphic spindle-stellate cells with a vague fascicular pattern. The nuclei were bland with only rare mitotic activity, and occasional multinucleation. The intervening stroma was typically abundant and ranged from myxoid to collagenous, with frequent rope-like collagen bundles. Three of the cases had a prominent vasculature ranging from numerous small curvilinear vessels to ectatic and branching staghorn-like vessels. Immunohistochemistry was negative for desmin, smooth muscle actin, S100, CD34, keratin, and epithelial membrane antigen. Each of the patients was treated by simple excision and none of the tumors were associated with local recurrence or metastasis. Based on their unique morphological and molecular attributes, we believe this represents a novel fibroblastic tumor for which we have tentatively proposed the name "PRRX-NCOAx-rearranged fibroblastic tumor."

Cytogenetics of Spindle Cell/Pleomorphic Lipomas: Karyotyping and FISH Analysis of 31 Tumors

BACKGROUND

Spindle cell/pleomorphic lipomas are benign tumors. Here, we present our cytogenetic data on 31 such tumors.

MATERIALS AND METHODS

G-banding chromosome analysis and (in selected cases) fluorescence in situ hybridization (FISH) using probes for FOXO1, RB1, and HMGA2 were performed.

RESULTS

Rearrangements of chromosome 13 were found in 58% of tumors. Chromosomes 6, 1, 12, and 11 were also involved in 42%, 26%, 26%, and 23% of tumors, respectively. FISH analysis showed heterozygous deletion of RB1 in seven samples with chromosome 13 aberrations. In four of them, FOXO1 was also deleted. In two tumors with 12q15 rearrangements, FISH confirmed that HMGA2 was targeted.

CONCLUSION

Structural rearrangements of 13q or losses of an entire chromosome 13 are the most common cytogenetic aberrations in spindle cell/pleomorphic lipomas. However, cytogenetic variation exists similarly to what is found in other lipomas, suggesting that various pathways may be responsible for tumorigenesis.

A rare case of cellular angiofibroma affecting the periurethral region in a 38-year-old woman

Cellular angiofibroma (CAF) is a rare, site-specific, benign mesenchymal tumour affecting both women and men in the genitourinary region. The tumour usually presents as a small, asymptomatic lesion involving the vulvovaginal regions in women and inguinoscrotal regions in men. We report the case of a 38-year-old woman presenting with a painless mass in the vulval region, especially on the right side of urethral meatus for 8 years with progressively increasing lower abdominal discomfort. A simple excision was performed. The diagnosis of CAF was confirmed histopathologically.

Consistent Involvement of Chromosome 13 in Angiolipoma

BACKGROUND/AIM

Angiolipoma is a rare benign soft tissue tumor composed of mature adipocytes and blood vessels. Genetic information on angiolipomas is scarce. With the single exception of one tumor which carried a t(X;2)(p22;p12), all angiolipomas hitherto investigated cytogenetically had normal karyotypes.

MATERIALS AND METHODS

G-banding chromosome analysis was performed on three short-term cultured angiolipomas. Fluorescence in situ hybridization (FISH) analysis using a commercially available RB1 deletion probe was also done.

RESULTS

All three angiolipomas had abnormal karyotypes with loss or structural rearrangement of chromosome 13. The first tumor had the karyotype 46,XY,-6,del(13)(q14),+mar[cp5], the second had 44~45,XY,t(1;10;15)(p21~22;q24;q24),-13[cp5], and the third karyotype was 43,XX,t(13;22;17) (q12;q13; q22~23)[14]. FISH analysis showed heterozygous and homozygous deletion of the RB1 probe in case 2 and 3, respectively. FISH analysis failed in case 1.

CONCLUSION

Chromosome 13 was consistently involved in all three angiolipomas.

Molecular Signature of Tumors with Monoallelic 13q14 Deletion: a Case Series of Spindle Cell Lipoma and Genetically-Related Tumors Demonstrating a Link Between FOXO1 Status and p38 MAPK Pathway

Spindle cell/pleomorphic lipomas (SCLs), cellular angiofibromas (CAFs) and mammary-type myofibroblastomas (MFBs) are rare benign mesenchymal tumors with monoallelic 13q14 deletion. They are predicted to have a common pathogenic mechanism due to shared similar histological and immunohistochemical features; however, pathological consequences of monoallelic 13q14 deletion remain unknown. We previously reported a CAF case with monoallelic 13q14 deletion in which the tumor expressed decreased levels of FOXO1 and RB1, both of which were encoded in 13q14, and increased reactive oxygen species (ROS) levels. We further demonstrated the activation of p38 mitogen-activated protein kinase (p38 MAPK) pathway induced by oxidative stress. We hypothesized that SCLs, CAFs and MFBs would share common molecular signatures involving FOXO1, ROS and p38 MAPK and that their expression patterns were different from those tumors without monoallelic 13q14 deletion such as solitary fibrous tumors (SFTs). We compared the expression levels of FOXO1, RB1, ROS markers and several signal transduction factors between SCLs and SFTs. SCLs expressed decreased levels of FOXO1 and RB1, whereas SFTs showed no change. Both tumor types exhibited increased markers of ROS; however, nuclear localization of phosphorylated p38 was significantly more frequent in SCLs than that in SFTs, suggesting p38 MAPK activation by oxidative stress. SFTs showed lower p38 MAPK activity and higher β-catenin expression, implying that oxidative stress was caused by increased cellular proliferation stress. Finally, CAFs and MFBs showed changes similar to those observed in SCLs. Overall, tumors with monoallelic 13q14 deletion showed shared molecular signatures that might be associated with pathogenesis.

Loss of chromosome 13 material in cellular angiofibromas indicates pathogenetic similarity with spindle cell lipomas

Background

Cellular angiofibroma is a rare benign mesenchymal neoplasm with morphological and immunohistochemical similarities to spindle cell lipoma. Karyotypic information on cellular angiofibroma is restricted to one case only which showed loss of material from chromosomes 13 and 16. A few other studies using fluorescence in situ hybridization showed deletions of the RB1 and FOXO1 loci, both of which are located in chromosome band 13q14. We present here cytogenetic data on two cellular angiofibromas with an abnormal karyotype.

Methods

G-banding and fluorescence in situ hybridization (FISH) analyses were done on two cellular angiofibromas.

Results

In both tumors, a rearrangement leading to loss of chromosome 13 material was seen, together with other structural chromosome abnormalities. FISH analysis showed heterozygous deletion of the RB1 locus (13q14) in both cases.

Conclusion

Our results demonstrate loss of chromosome 13 material in cellular angiofibroma, though not as the sole cytogenetic change, confirming the (cyto)genetic similarity of these tumors with spindle cell lipomas.

Spindle Cell Lipoma in an End-Stage Renal Allograft: Case Report

BACKGROUND

Spindle cell lipoma is an uncommon variant of lipoma and usually occurs as a solitary, subcutaneous, and well circumscribed lesion in the posterior neck, shoulders, and back of older men. Primary renal lipomas are rarely reported. Spindle cell lipoma in the kidney has not been previously described in the literature.

CASE REPORT

A 60-year-old Chinese man suffered graft failure 10 years after living related donor kidney transplantation. During cancer surveillance, he was found to have a mass in the renal allograft, which increased in size and was suspicious for renal cell carcinoma on computerized tomographic scan. The patient underwent renal graft explantation. Grossly, the kidney was atrophic, containing a 6.5 cm yellowish solid lesion without hemorrhage and necrosis in the renal sinus fat. Microscopically, the lesion was composed of variably sized adipocytes and cellular areas of bland spindle cells with no cytologic atypia. There were prominent slender blood vessels within the lesion, along with focal myxoid change as well as scattered mast cells and inflammatory cells. Lipoblasts were not identified. The spindle cells were positive for CD34 and negative for Melan-A, HMB45, S100, and SMA. Pax-2 stain was nonspecific. MDM2 amplification by means of fluorescence in situ hybridization (FISH) and overexpression by immunohistochemistry were negative. The Ki-67 proliferation index was <1%. Interphase FISH revealed loss of 13q and 16q in the tumor.

CONCLUSIONS

Renal spindle cell lipoma is a rare benign tumor. Angiomyolipoma and well differentiated liposarcoma are the main differential diagnoses. Immunohistochemistry and cytogenetic techniques are helpful in differentiating it from malignant entities.

Spindle Cell Lipomas Arising at Atypical Locations

OBJECTIVES

Spindle cell lipomas (SCLs) are benign lipomatous neoplasms that classically arise in the posterior neck, upper back, and shoulders of older male patients. We sought to characterize the occurrence of this entity at nonclassic sites.

METHODS

All cases of SCL arising at atypical sites were retrieved from our archives.

RESULTS

Of 439 total cases of SCL, 57 arose at atypical locations in 32 men and 25 women (age range, 27-79 years). The tumor sites included leg (n = 23), buttock/perineum/inguinal (n = 10), forearm (n = 9), finger (n = 9), foot (n = 2), toe (n = 2), hand (n = 1), and flank (n = 1). CD34 was positive staining in all cases tested (52/52), while desmin was negative in most tumors (48/50). Thirty-eight of 38 cases tested exhibited loss of Rb expression. No cases showed CPM/MDM2 amplification (0/48). No local recurrences have been reported (n = 39).

CONCLUSIONS

SCLs may arise in the trunk, lower extremities, and distal upper extremities. While most SCLs arising in classic sites occur in male patients, there is a relatively equal sex distribution in tumors at atypical sites. Pathologists should be aware that SCLs arise at atypical locations to avoid misclassification as other lipomatous neoplasms, including atypical lipomatous tumor.

Mammary-Type Myofibroblastoma: A Report of Two Cases

Mammary-type myofibroblastoma (MFB) is a rare, benign spindle cell neoplasm occurring along the milkline, with extension from the mid-axilla to the medial groin. It is histologically and immunohistochemically identical to MFB of the breast and is part of a spectrum of lesions that includes spindle cell lipoma and cellular angiofibroma. Recently, we experienced two cases of mammary-type MFB involving male patients aged 30 and 58 years, respectively. The tumors were located in the right scrotal sac and in the right axilla. Wide excisions were performed. Microscopically, the masses were composed of haphazardly arranged, variably sized fascicles of bland spindle cells and were admixed with mature fat tissue. The spindle cells in both cases showed immunopositivity for desmin and CD34 and negativity for smooth muscle actin. Loss of retinoblastoma (RB)/13q14 loci is a characteristic genetic alteration of mammary-type MFB, and we identified loss of RB protein expression by immunohistochemical staining. We emphasize the importance of awareness of this rare neoplasm when a spindle cell neoplasm is accompanied by desmin immunopositivity. The second patient was alive without recurrence for 20 months, and the first patient had not been followed.

Adipose-Derived Stromal Cells from Lipomas: Isolation, Characterisation and Review of the Literature

OBJECTIVE

The aim of this study was to characterize adipose-derived stromal cells (ADSCs) from patients diagnosed with multiple symmetric lipomatosis (MSL) in order to obtain potentially new insights into the pathophysiology, pathogenesis and treatment of this disease.

METHODS

Cells from the stromal vascular fraction were analysed by the colony-forming efficiency assay and flow cytometry using standard markers. Moreover, the power of adipogenic plasticity was evaluated. Finally, a literature review was performed from 1982 to 2015 using the US National Institutes of Health's PubMed database.

RESULTS

Three European-descent patients diagnosed with either MSL type I or II could be identified for analysis. The resulting mean colony-forming efficiency assay was 14.3 ± 5%. Flow-cytometric analysis of the ADSCs revealed high levels of CD34 (70 ± 9%), CD45 (37 ± 13%) and CD73 (55.8 ± 14%), whereas low levels of CD31 (16.8 ± 14%) and CD105 (5.8 ± 0.7%) were detected. Furthermore, ADSCs showed a strong adipogenic potential, which is in line with the literature review. The stem cell pool in lipoma shows several alterations in biological activities, such as proliferation, apoptosis and stemness.

CONCLUSIONS

ADSCs from lipoma may be interesting in the application of regenerative medicine. We discuss possible molecular treatment options to regulate their activities at the source of the MSL.

Diagnostically Challenging "Fatty" Retroperitoneal Tumors

A variety of benign and malignant retroperitoneal mesenchymal lesions may have a component of adipose tissue, including entities such as lipoma, myolipoma, angiomyolipoma, solitary fibrous tumor, genital stromal tumors, and well-differentiated/dedifferentiated liposarcoma. Although definitive diagnosis is usually straightforward on the complete resection specimen, it is often more difficult to workup these lesions on small biopsy samples. This review focuses on challenging diagnostic scenarios of retroperitoneal lesions with a "fatty" component and provides major differential diagnoses for commonly encountered morphologic patterns, clinicopathologic features of the various entities, and strategy for use of ancillary techniques, such as immunohistochemistry and cytogenetic studies.

Genital soft tissue tumors

Mesenchymal neoplasms of the vulvovaginal and inguinoscrotal regions are among the most diagnostically challenging specimens in the pathology laboratory owing largely to their unique intersection between general soft tissue tumors and relatively genital-specific mesenchymal tumors. Genital stromal tumors are a unique subset of soft tissue tumors encountered at this location, and this group includes fibroepithelial stromal polyp, superficial (cervicovaginal) myofibroblastoma, cellular angiofibroma, mammary-type myofibroblastoma, angiomyofibroblastoma and aggressive angiomyxoma. Aside from the striking morphologic and immunophenotypic similarity that is seen with these entities, there is evidence that a subset of genital stromal tumors may be linked genetically. This review will focus on simplifying this group of tumors and provide the pathologist or dermatopathologist with practical management information. Smooth muscle tumors of the external genitalia will also be discussed.

Paratesticular cellular angiofibroma with atypical (bizarre) cells: case report and literature review

We report the extremely unusual occurrence of a cellular angiofibroma (CAF) with atypical (bizarre) cells in the spermatic cord. We present a 63-year-old man, who was referred to the Urology Service with a six-month history of a slowly growing painless nodule in the right inguino-scrotal area. The clinical impression was that of a lipoma. The mass was locally excised. Gross examination showed a well-circumscribed neoplasm attached to the spermatic cord and measuring 5cm in the greatest dimension. Microscopic examination of the tumor showed the appearance of CAF with scattered severely atypical (bizarre) cells distributed throughout the lesion. By immunohistochemistry, atypical cells showed diffuse expression of p16, CDK-4, CD34 and vimentin. Keratin AE1/AE3, S-100 protein, p53, and epithelial membrane antigen were negative. The patient is free of disease two months after tumor excision. To the best of our knowledge, this is the third case of CAF with atypical (bizarre) cells occurring in the paratesticular area. Pathologists should be aware of this morphological variation of CAF to avoid misdiagnosis and over-treatment.

Solitary fibrous tumor: is there a molecular relationship with cellular angiofibroma, spindle cell lipoma, and mammary-type myofibroblastoma?

Solitary fibrous tumor (SFT) is a mesenchymal tumor characterized by ovoid cells, branching blood vessels, stromal hyalinization, and CD34 immunoreactivity. Studies have shown loss of 13q in a group of morphologically similar entities, including cellular angiofibroma, mammary-type myofibroblastoma, and spindle cell lipoma. The histologic and immunophenotypic overlap between SFT and the latter group of tumors suggests that these tumors may be genetically linked. We tested a group of 40 SFTs to assess for loss of RB1 (13q14) by fluorescence in situ hybridization (FISH). All 38 SFTs with evaluable signals failed to show loss of RB1 (13q14) by FISH. All cases of cellular angiofibroma (1/1), spindle cell lipoma (6/6), and mammary-type myofibroblastoma (4/4), which were used as a control group, showed monoallelic or biallelic loss of RB1. The absence of RB1 loss in SFTs suggests that they are not related to cellular angiofibroma, mammary-type myofibroblastoma, or spindle cell lipoma.

Cellular angiofibroma: analysis of 25 cases emphasizing its relationship to spindle cell lipoma and mammary-type myofibroblastoma

Cellular angiofibroma represents a rare benign mesenchymal tumor, occurring mainly in the superficial soft tissue of the genital region. The involvement of 13q14 in some cases confirmed the morphological suggested link with spindle cell lipoma and mammary-type myofibroblastoma. We analyzed the clinicopathological and immunohistochemical features of 25 cases, and performed in a number of cases additional molecular studies. There were 17 female and 8 male patients (age ranged from 27 to 83 years); females tended to be younger. A marked predilection for the vulva (n=13) was observed, and neoplasms in males were predominantly located in the inguinal region (n=4), and one case each in the scrotum, perianal, the knee, and the upper eyelid. The tumors arose most commonly in the superficial soft tissue and were well circumscribed in all but two cases. The tumor size ranged from 1 to 9 cm. All lesions were composed of spindle-shaped cells associated with numerous small- to medium-sized blood vessels; however, a broad morphological variation with foci of lipogenic differentiation in nine cases and sarcomatous transformation in one case was found. By immunohistochemistry, 11 out of 22 cases expressed CD34. A focal reaction for α-smooth muscle actin was observed in 9 out of 22 cases, and two cases each stained weak and focally positive for epithelial membrane antigen and CD99. In all seven cases tested, a monoallelic deletion of RB1 was detected by FISH analysis. Follow-up, available in 14 patients, showed neither local recurrence nor metastasis. In conclusion, we affirm the link between cellular angiofibroma, spindle cell lipoma, and mammary-type myofibroblastoma, showing a spectrum of one entity with morphological variations dependent on anatomic location.

Left supraclavicular spindle cell lipoma

Background. Spindle cell lipoma (SCL) is a benign lipomatous tumour, typically occurring in the posterior neck, shoulder or upper back of elderly males. They compose of fat, CD34 positive spindle cells, and ropey collagen on a myxoid matrix. This case highlights a rare presentation of SCL and the need for pre-operative diagnosis. Case Report. A 63-year-old gentleman presented with a pre-existing left supraclavicular mass that had recently increased in size. FNA and CT Scans were performed and results discussed in the mutidisciplinary team meeting. Excisional biopsy was recommended. Radiology. CT neck showed a left supraclavicular mass of fatty density with fine internal septations. A low-grade liposarcoma could not be excluded. Histopathology. FNA was indeterminate. Histology of specimen showed bland spindle cells with no evidence of malignancy. Immuno-histochemistry showed SCL with CD34 positivity and negative staining on CDK4 and p16. Management. Excision biopsy of the mass was performed which was technically difficult as the mass invaginated around the brachial plexus. The patient recovered well post-operatively with no neurological deficits. Conclusion. Spindle cell lipoma is a rare benign tumour and a pre-operative diagnosis based on the clinical context, imaging and immuno-histochemistry is crucial to management.

Mesenchymal Lesions of the Lower Genital Tract

A variety of site-specific mesenchymal lesions of the lower genital tract may occur, which are often diagnostically challenging because of their morphologic overlap. Some of this morphologic homogeneity presumably stems from a potentially shared origin from the specialized superficial stroma of the distal female genital tract. Despite shared appearances, morphologic distinction remains the gold standard for diagnosis of most of these lesions, as immunoperoxidase staining is often not helpful in their distinction.

Cellular angiofibroma of oral mucosa: report of two cases

Cellular angiofibroma is a benign vascular neoplasm that typically arises in the vulva, perineal, and paratesticular region. Microscopically the lesions exhibit multiple small, non-dilated capillary channels, many of which contain erythrocytes. The endothelial lining cells are prominent, with monomorphic oval nuclei. Interposed among the vessels are both delicate and mature collagen fibers with fibroblastic hypercellularity that is variable in older lesions where sclerosis is prominent. The lesions usually do not recur following simple excision. Recent evidence indicates that cellular angiofibromas may be cytogenetically related to spindle cell lipoma. This represents the first reported instances of cellular angiofibroma in the oral cavity.