The HIV-positive skin biopsy

Dermatological disorders are a frequent presenting feature of HIV infection and/or AIDS. More than 90% of HIV-infected patients will suffer from one or more skin diseases during the course of their illness. This trend is reflected in the increasing number of skin biopsies from HIV-positive patients in those parts of the world where HIV infection/AIDS is highly prevalent. Histopathologists are therefore required to possess a working knowledge of the broad spectrum of cutaneous manifestations of HIV infection. These include the range of dermatoses that are specific to HIV infection, the more common dermatoses occurring with greater frequency (or modified by) HIV infection/AIDS, the spectrum of infectious diseases (often opportunistic) caused by viruses, bacteria, fungi, protozoa and even arthropods, and neoplastic conditions such as Kaposi sarcoma and B-cell non-Hodgkin lymphoma. The risk for adverse skin reactions to certain drugs is also greatly increased. Although the introduction of highly active antiretroviral therapy has resulted in a dramatic decrease in opportunistic infections, several of these drugs may result in adverse reactions in the skin. Skin biopsies play a vital diagnostic role when different diseases present with clinically similar skin lesions. Biopsy material should always be examined carefully to exclude dual pathology. The diagnosis may need to be confirmed with histochemical and immunohistochemical stains, and/or molecular studies. Where indicated, additional biopsies for microbiological culture should always be recommended. The examination of multiple serial sections often proves invaluable. A diagnostic approach is given based on the predominant histological reaction pattern, with an emphasis on clinicopathological correlation.

Apocrine mixed tumor of the skin (“mixed tumor of the folliculosebaceous-apocrine complex”)

BACKGROUND

A systematic analysis of the entire spectrum of various forms of differentiation and metaplastic epiphenomena in cutaneous apocrine mixed tumor (AMT) has never been performed.

OBJECTIVE

The purpose of our study was to study a large number of cutaneous mixed tumors so as to fully characterize the entire spectrum of differentiations and metaplastic changes that may occur in the epithelial, myoepithelial, and stromal components of AMT.

METHODS

This article reports a light-microscopic study of 244 cases of cutaneous AMT, complemented by a literature review.

RESULTS

All types of differentiation along the lines of the folliculosebaceous-apocrine unit can be seen in AMT. The spectrum of metaplastic changes in the epithelial components includes squamous metaplasia, mucinous metaplasia, oxyphilic metaplasia, clear cell change, columnar metaplasia, hobnail metaplasia, and cytoplasmic vacuolization. The following changes in the myoepithelial component were documented: clear cell change, hyaline cells, plasmacytoid cells, spindling, and collagenous spherulosis. Stromal alterations included chondroid metaplasia, osseous metaplasia, and adipose metaplasia.

LIMITATIONS

This study utilizes tissue specimens that mainly came as consultations; therefore some inherent selection bias exists.

CONCLUSIONS

AMT displays a wide range of differentiation and metaplastic changes in its epithelial, myoepithelial, and stromal components. These phenomena are not mutually exclusive. When unduly prominent, they may present diagnostic pitfalls. Our findings corroborate those of previous publications, stressing the remarkable diversity of differentiation and metaplasias that may be found in cutaneous AMT. We propose that the most appropriate name for these lesions is "mixed tumor of the folliculosebaceous-apocrine complex."

The squamous variant of eccrine porocarcinoma: a clinicopathological study of 21 cases

AIM

Squamous differentiation in eccrine porocarcinoma (EPC) is an unusual phenomenon that has rarely been reported in the literature. This study describes the clinical and pathological findings in a series of 21 cases of EPC showing extensive squamous differentiation.

METHODS

The H&E-stained sections, epithelial membrane antigen and carcinoembryonic antigen immunohistochemical stains were reviewed for each case. The following variables were examined: age, gender, race, site and size of the EPC. The prevalence of other cutaneous lesions and/or underlying systemic disease was also documented.

RESULTS

There was an almost equal gender distribution. Mean age was 61.5 years and the average tumour size was 46.5 mm. An inordinately large number (10/21, 48%) of EPCs occurred in black patients. The tumours were located at various sites with the extremities predominating (10/19, 53%). Seven patients developed other sun-induced skin tumours, three patients were renal transplant recipients, and two patients were HIV-positive, one of whom also suffered from albinism. Six of the 11 patients in whom follow-up was available had an adverse outcome: local recurrence developed in one patient, one patient developed nodal metastases, and one patient experienced both local recurrence and nodal metastases, and of the three patients who died of disease, two developed distant metastases.

CONCLUSION

The findings suggest a possible role for ultraviolet radiation and chronic immunosuppression in the induction of malignant squamous differentiation in a subset of EPCs. Further reports on this histological variant of EPC are required to determine whether a pathogenetic link does indeed exist or whether these tumours simply represent a unique variant of squamous cell carcinoma with divergent acrosyringial differentiation.

Pagetoid reticulosis with CD30 positivity and cytotoxic/suppressor cells

Pagetoid reticulosis (PR) is a low-grade primary cutaneous T-cell lymphoma that usually presents as a solitary, slowly enlarging erythematous or hyperkeratotic plaque on the distal areas of the extremities. Histopathologically, it is characterized by a dense, band-like infiltrate of atypical lymphocytes with prominent epidermotropism within a hyperplastic epidermis, and immunophenotypic studies show in most cases, a CD4-positive T-helper phenotype for the neoplastic lymphocytes. We describe an African man with a more than 20-year history of an acral lesion of PR, which was histopathologically characterized by lymphocyte immunophenotype consisting of CD8- and CD30-positive cells. We discuss the differential diagnosis with other primary cutaneous lymphoproliferative disorders showing similar immunophenotype. This case shows that CD30-positive PR should be included as a rare variant within the spectrum of CD30-positive primary cutaneous lymphoproliferative disorders. As in other primary cutaneous CD30-positive lymphoproliferative processes, lesions of CD30-positive PR show an indolent course and a benign biological behavior.

Papular follicular eruptions in human immunodeficiency virus-positive patients in South Africa

BACKGROUND

Papular and follicular eruptions, such as papulopruritic eruption, eosinophilic folliculitis, and infective folliculitis, are relatively common disorders in patients infected with the human immunodeficiency virus (HIV). These conditions may show considerable clinical overlap.

OBJECTIVE

To assess the relative proportion of pruritic papular cutaneous eruptions in South Africans with HIV-associated dermatoses, and to correlate the clinical and histologic features of these lesions.

METHODS

The clinical and histologic features of papular follicular eruptions were correlated in 40 consecutive black HIV-positive patients who underwent skin biopsy.

RESULTS

The clinical features were similar in all patients and consisted of widespread papules and pustules involving the face, limbs, and trunk. The most common histologic finding was acute suppurative folliculitis, seen in 27 patients (67.5%). In most cases, no cause was found for the suppuration. Papulopruritic eruption of HIV was diagnosed in six patients (15%), HIV-associated eosinophilic folliculitis in four (10%), Pityrosporum folliculitis in two (5%), and acne in one (2.5%). Concordance between the initial clinical diagnosis and the final histopathologic diagnosis was achieved in only 27.5% of cases.

CONCLUSION

Skin biopsy remains an important adjunct to the correct diagnosis and classification of papular and follicular eruptions in HIV-positive patients.

Pilomatrix carcinomas contain mutations in CTNNB1, the gene encoding beta-catenin

Mutations in beta-catenin are present in benign pilomatrixomas. beta-catenin is a downstream effector in the WNT-signalling pathway, acting as a signal for differentiation and proliferation. Mutations in CTNNB1, the gene encoding beta-catenin, are present in a wide variety of benign and malignant neoplasms. We examined beta-catenin in a series of pilomatrix carcinomas (15 cases) by using immunohistochemistry and DNA sequencing of exon 3 from CTNNB1, and compared these to a series of benign pilomatrixomas (13 cases). All 11 pilomatrix carcinomas available for examination showed nuclear localization of beta-catenin and mutations in exon 3 similar to those demonstrated in benign pilomatrixomas. Two of 11 pilomatrix carcinomas showed significant nuclear accumulation of p53, whereas this was absent in all 13 benign pilomatrixomas. Expression of nuclear cyclin D1 was similar in both benign pilomatrixomas and pilomatrix carcinomas. Clinical follow-up from the 15 malignant cases reported in this study and by others indicates that wide excision offers superior control of local recurrence, compared to simple excision. Immunohistochemical and molecular analysis of beta-catenin reveals that both pilomatrix carcinomas and benign pilomatrixomas harbour mutations in beta-catenin. This implies a common initial pathogenesis and is compatible with the proposition that pilomatrix carcinomas may at least on occasion arise from their benign counterparts.

Adenoid cystic carcinoma stage Ib1 treated with radical surgery displaying human papilloma virus 33 (HPV 33): immunoelectron microscopy and review

BACKGROUND

The presence of human papilloma virus (HPV) 33 and possible myoepithelial differentiation in an adenoid cystic carcinoma of the cervix (ACC) Ib1 and the clinical outcome are reported.

CASE

The case is an ACC, stage Ib1 harboring HPV 33, which was treated by radical hysterectomy and lymphadenectomy only. Human papilloma virus analysis of the tumor was done by means of nonisotopic in situ hybridization and polymerase chain reaction. Additionally immunoelectron microscopy was performed.

CONCLUSION

Our patient had a vault recurrence 12 months after class III (Meigs) hysterectomy. The cancer tissue was totally excised, the lymphnodes (n = 31) were negative, and there was no lympho-vascular invasion and no perineural infiltration. The primary tumor displayed HPV 33 integration and features suggesting myoepithelial differentiation. We would recommend a low threshold for the use of radiotherapy in the management of similar findings.

Ganglioneuroblastic differentiation in a primary cutaneous malignant melanoma

Ganglioneuroblastic differentiation in malignant melanomas is an exceedingly rare event. Although there has been a single report of this occurrence in a metastatic melanoma, divergent ganglioneuroblastic differentiation has not been documented previously in a primary cutaneous lesion of melanoma. The present report describes an unusual case of invasive melanoma arising on the lower leg of a 61-year-old woman. The 16.9-mm thick tumor showed extensive ganglioneuroblastic differentiation, which was confirmed both immunohistochemically and ultrastructurally. Although the prognostic significance of this observation remains uncertain, the unique case reaffirms the potential morphologic diversity of melanomas and suggests a shared histogenetic origin from a common neural crest derivative.

Five cases of cutaneous Rosai-Dorfman disease

Rosai-Dorfman disease (RDD), previously known as sinus histiocytosis with massive lymphadenopathy, is a benign, idiopathic histiocytic proliferative disorder. It commonly affects lymph nodes, but any organ of the body may be involved. Histological findings include characteristic large, pale, histiocytic cells (Rosai-Dorfman cells) exhibiting cytophagocytosis. Immunohistochemically, these histiocytes are positive for S-100 protein and CD68, but stain negatively for CD1a. On electron microscopy, Birbeck granules are absent. RDD limited to the skin is rare, less than 30 cases having been reported to date. We present five further cases of purely cutaneous RDD. Three presented as solitary nodules and one as a large, well-circumscribed plaque. The fifth patient, who was HIV positive, had a rosacea-like facial eruption.

Cutaneous rosai-dorfman disease is a distinct clinical entity

Rosai-Dorfman disease (RDD) is a rare but distinctive clinicopathologic entity of unknown etiology affecting lymph nodes as well as extranodal sites. Although cutaneous involvement in RDD is common, purely cutaneous disease is rare and not well documented. We report 22 patients with cutaneous and superficial subcutaneous RDD. The lesions presented as papules and nodules, often with discoloration (9/22) and frequent multifocality (13/22), without predilection for a specific site of the body. Age distribution was wide and ranged from 15 to 68 years, with a median of 43.5 years. Of the 17 patients for whom information on racial background was available, 7 were Asian, 8 were white, and 2 were black, with a marked female predominance (2:1). The lesions resolved in 6 of 13 patients for whom follow-up data were available, regardless of the treatment given. Lesions persisted or recurred in 7 patients. Histologically, the lesions are invariably characterized by a proliferation of polygonal S100-positive histiocytes showing emperipolesis and a mixed inflammatory infiltrate. This study characterizes the histologic spectrum of cutaneous RDD in regard to variation in the numbers of typical S100-positive histiocytes and emperipolesis, variation in the quality and quantity of the inflammatory response, and the degree of stromal fibrosis, which resulted in a strikingly storiform growth pattern in six lesions and a lobulated pattern in two lesions. Whereas the clinical as well as histologic appearance of the cutaneous and subcutaneous lesions in the purely extranodal forms of RDD is indistinguishable from that of systemic RDD, this study emphasizes that purely cutaneous RDD is a distinct clinical entity in regard to its epidemiology and remains localized to the skin even with long-term follow-up. Patients with purely cutaneous RDD are of an older age at onset of disease (median = 43.5 years), with a reversed male/female ratio. There are no significant systemic extracutaneous or serologic manifestations. Whereas systemic RDD is commonly seen in blacks and only rarely reported in Orientals, the majority of the patients in this series with purely cutaneous RDD are Asians and whites.

A reappraisal of "basaloid carcinoma" of the cervix, and the differential diagnosis of basaloid cervical neoplasms

"Basaloid carcinoma" of the uterine cervix is a neglected and underrecognized entity that is not included in the current World Health Organization's classification of cervical neoplasms. Historically, this term has been used synonymously with adenoid basal carcinoma (ABC). In recent years, however, it has become evident that a broad spectrum of basaloid cervical neoplasms exist. At one end of the spectrum are low-grade lesions, such as ABC; at the opposite end of the spectrum there are aggressive tumors, including adenoid cystic carcinoma, large cell neuroendocrine carcinoma, and basaloid squamous carcinoma. The purpose of this review is to revisit the concept of basaloid tumors of the cervix, to define their morphologic spectrum, and to address potential pitfalls in the differential diagnosis. To avoid confusion, use of the term "basaloid squamous cell carcinoma" is recommended when diagnosing a cervical tumor with histologic features of "basaloid carcinoma," as seen in other anatomic sites. A proposed classification of basaloid tumors of the uterine cervix is also presented.

Gliomatosis of the brain and spinal cord masquerading as infective lesions

BACKGROUND

Gliomatosis of the brain or spinal cord is an infiltrating glial neoplasm that shows widespread invasion of the central nervous system with relative sparing of the underlying cytoarchitecture. Acceptance of the idea that the condition represents a distinct entity remains controversial in the absence of conclusive pathogenetic data. The clinico-pathological problems and difficulties in the ante-mortem diagnosis as well as the clinical and pathological similarities to infective lesions are evaluated.

METHODS AND RESULTS

Three cases of cerebral and spinal gliomatosis are presented that clinically mimicked infective lesions and were diagnosed and treated as such. The correct diagnosis in each case was only made at post-mortem examination. The ante-mortem diagnosis of this rare tumor remains difficult owing to poor correlation of clinical, neuroradiological, and neuropathological findings.

CONCLUSION

Gliomatosis of the brain and spinal cord may simulate infective lesions owing to difficulty in ante-mortem diagnosis because of vagueness of physical, radiological, and pathological findings. It is a diagnostic pitfall particularly in our setting where there is a high incidence of HIV/AIDS and patients often present with opportunistic infections such as mycobacterial, fungal, and/or viral infections, which show an atypical clinical picture and radiological findings. Multifocal neurologic deficit with noncontrast enhancing lesions that show diffuse contiguous involvement with overall preservation of the spinal or cerebral architecture and do not respond to infective treatment could suggest a diagnosis of gliomatosis cerebri.

Detection of human papillomavirus in large cell neuroendocrine carcinoma of the uterine cervix: a study of 12 cases

AIM

To investigate the role of human papillomavirus (HPV) in large cell neuroendocrine carcinoma (LCNEC) of the uterine cervix.

METHODS

Twelve archival, immunohistochemically and/or electron microscopically confirmed cases of cervical LCNEC were studied. Non-isotopic in situ hybridisation (NISH) was performed on the formalin fixed, paraffin wax embedded biopsies using digoxigenin labelled probes to HPV types 6, 11, 16, 18, 31, and 33. The tumours were then subjected to polymerase chain reaction (PCR) analysis using GP5+/GP6+ consensus primers to the HPV L1 gene, in addition to type specific primers to the E6 and E6/E7 genes.

RESULTS

HPV-16 was detected by NISH and/or PCR in seven of the 12 carcinomas. Two additional tumours were HPV-18 positive by NISH and/or PCR. HPV DNA was not detected in the three remaining cases.

CONCLUSION

Integration of high risk HPV, in particular type 16 and to a lesser extent type 18, is associated with this uncommon variant of cervical carcinoma.

Adult extrarenal Wilms tumor occurring in the uterus

Five previous cases of extrarenal Wilms tumor (EWT) occurring in the uterus have been reported. The oldest patient was 22 years. We report a case of uterine EWT occurring in a 42-year-old woman. Histologically, there was typical triphasic differentiation, including epithelial, blastemal, and mesenchymal elements. The important differential diagnosis in this age group, the malignant mixed mullerian tumor, is excluded by the absence of glomeruloid structures and primitive tubules. The exact histogenesis of EWT is unknown but most likely relates to the presence of nephrogenic rests occurring in the female genital tract.

Large-cell neuroendocrine carcinoma of the uterine cervix--a clinicopathological study of five cases

OBJECTIVE

The present study describes 5 cases of large-cell neuroendocrine carcinoma (LCNEC) of the uterine cervix, evaluating their clinical features and pathological profiles.

METHODS

Clinical data were obtained from the patients' clinical files at the combined gynaecological-oncology unit of Johannesburg Hospital and the University of the Witwatersrand Medical School, Johannesburg, South Africa. A histopathological diagnosis was obtained after biopsy material from all 5 patients was examined microscopically and subjected to immunohistochemical staining with MNF116 (pankeratin) synaptophysin and chromagranin A, all of which are neuroendocrine markers. Two patients received pelvic radiotherapy only. None of the 5 patients in this series received chemotherapy or underwent surgery.

RESULTS

All 5 patients were adult females, with an average age of 57.3 years. The majority were multiparous, with the most common presenting complaint being vaginal bleeding. Three of the 5 patients presented with advanced-stage cervical carcinoma, with evidence of metastases in 2 of them. Treatment responses and long-term survival in our series proved to be disappointing as 3 of the 5 patients died in less than 6 months. On histopathological examination, all 5 tumours showed features of a high-grade poorly differentiated malignant neoplasm with ulceration and extensive tumour necrosis including trabecular and organoid growth patterns. All 5 neoplasms also showed strong immunoreactivity for MNF116, while their endocrine nature was confirmed by staining for synaptophysin in all cases. None of the tumours showed positive straining for chromagranin A.

CONCLUSIONS

LCNECs are rare tumours and distinct from other neoplasms of the uterine cervix. The results of this study reaffirm the biologically aggressive nature of this uncommon tumour and its very unfavourable prognosis.

Carcinosarcoma of the uterine cervix: a report of eight cases with immunohistochemical analysis and evaluation of human papillomavirus status

Carcinosarcomas (malignant Müllerian mixed tumors [MMMTs]) of the uterine cervix are rare neoplasms. This report describes the morphology, immunohistochemical profiles, and human papillomavirus (HPV) status of eight cervical MMMTs. Patients' ages ranged from 32 to 93 years (mean, 61 years). Seven cases showed in situ squamous cell carcinoma (SCC). The invasive epithelial component (EC) was composed of combined adenoid basal carcinoma, basaloid SCC, and adenoid cystic carcinoma (ACC) in two cases. Keratinizing SCC, large cell nonkeratinizing SCC, undifferentiated carcinoma, and basaloid SCC predominated in the remaining tumors, one of which had admixed ACC. The sarcomatous component (SC) was homologous and spindled with admixed myxoid areas in three lesions. The ECs and SCs in six MMMTs showed dual immunostaining with epithelial membrane antigen and the pan-keratin marker, MNF116. The SC was vimentin-positive in seven cases. Five tumors had a vimentin-positive EC. The SC was positive for muscle specific actin and/or smooth muscle actin in seven lesions, of which four were desmin-positive. Polymerase chain reaction (PCR) using GP5+/GP6+ L1 consensus primers detected HPV DNA in all eight cases. Nonisotopic in situ hybridization with digoxigenin-labeled probes to HPV types 6, 11, 16, 18, 31 and 33 demonstrated integrated HPV 16 in three cases, not only in the EC, but also in nuclei of the SC. This is the first study to implicate HPV in the evolution of cervical MMMTs. The above observations lend support to a metaplastic theory of histogenesis.

Pemphigus vulgaris of the uterine cervix revisited: case report and review of the literature

Pemphigus vulgaris is an autoimmune disease characterized by acantholytic blisters and erosions involving the oral mucosa, skin, and less frequently other mucosal surfaces. Although the cytology of scrapings from the cutaneous and oral lesions has been well-documented, there are relatively few reports in the literature of the cytologic appearance of pemphigus on cervicovaginal smears. This report documents a case of pemphigus involving the cervix, in which the diagnosis was not known at the time of the cervical smear and biopsy. The cytologic features of this case and those in the literature are described in detail, highlighting the necessity of awareness of the disease and its presentation on cervicovaginal smears, in preventing an overdiagnosis of neoplasia.

Adenoid cystic and adenoid basal carcinoma of the uterine cervix: comparative morphologic, mucin, and immunohistochemical profile of two rare neoplasms of putative 'reserve cell' origin

Adenoid cystic carcinomas (ACCs) and adenoid basal carcinomas (ABCs) are rare neoplasms of the uterine cervix that are currently regarded as distinct clinicopathologic entities. Accurate distinction between ABCs and ACCs is of clinical importance because of differences in their biological behavior. This study compares the morphologic, mucin, and immunohistochemical profiles of 18 cervical ACCs, 8 ABCs, and 1 combined ABC-ACC. Serial sections from the 27 cases were stained with hematoxylin and eosin, periodic acid-Schiff-diastase, mucicarmine, and alcian blue and subjected to a panel of immunoperoxidase markers, namely, MNF116, CAM 5.2, CK7, CK20, epithelial membrane antigen, carcinoembryonic antigen (CEA), S-100, HHF 35, laminin, and type IV collagen. One ACC was also examined ultrastructurally. Almost all patients were postmenopausal black women. The distinction between ABC and ACC was best made morphologically. Divergent epithelial differentiation was seen in 18 cases (11 ACCs, 6 ABCs, and 1 ABC-ACC). Six cases with intact surface epithelium showed a high grade squamous intraepithelial lesion. There was no significant difference in mucin staining. Both tumor types had a similar immunohistochemical profile, apart from type IV collagen and laminin staining, which occurred exclusively in relation to the extracellular basement membranelike material in the ACC. Eleven ACCs and three ABCs were S-100-positive, including the respective ACC and ABC components of the combined ABC-ACC. Eight of the S-100-positive neoplasms with ACC morphology also stained with HHF 35, suggesting myoepithelial differentiation. The latter was confirmed in one ACC examined ultrastructurally. The similar clinical profiles, apart from the different biological behavior, capacity for divergent differentiation, and the occurrence of ABC areas in some ACCs and vice versa suggest that these tumors may share a common histogenesis, forming part of a morphologic and biologic spectrum of basaloid cervical neoplasms of putative "reserve cell" origin. Circumstantial evidence suggests that ABC may be a precursor of cervical ACC.

Primary mucinous carcinomas of the skin express TFF1, TFF3, estrogen receptor, and progesterone receptors

Mucinous carcinoma may present at various sites, including the breast and the gastrointestinal tract. Rarely, such tumors arise within the skin. Comparatively, breast lesions are relatively common and usually associated with a good prognosis. When pure, they are typically estrogen (ER) and progesterone receptor (PR) positive and responsive to tamoxifen. The authors studied 12 mucinous carcinomas of the skin and compared the morphology with that of typical mammary lesions. The authors also evaluated for expression of estrogen receptor, progesterone receptor, and the mucus-associated peptides of the trefoil factor family (TFF), TFF1 (formerly pS2) and TFF2 (formerly SP), using immunohistochemistry. The localization of mRNAs for TFF1, TFF2, and TFF3 (formally ITF) was also studied in a subset of three tumors, using in-situ hybridization with S35 labeled riboprobes. The Grimelius stain was used to look for evidence of neuroendocrine differentiation. Eight resembled type A mucinous carcinomas of the breast, two resembled type B, and one had composite features. The 12th was a papillary neoplasm. The two type B tumors exhibited argyrophilia. All showed strong nuclear staining with the estrogen receptor antibody but a more varied pattern with antibodies to progesterone receptor and TFF1. None labeled for TFF2. The detection of TFF1 in mammalian skin is a novel finding. Cutaneous mucinous carcinoma shows strong similarities to its mammary counterpart, including expression of estrogen receptor, TFF1, and TFF3 mRNA. These observations suggest that some mucinous carcinomas of the skin might respond to antiestrogenic therapies.

Epithelioid psammomatous melanotic schwannoma with osseous metaplasia

Psammomatous melanotic schwannoma is a very rare soft tissue neoplasm, which is clinically, biologically, and histologically distinct from conventional schwannoma. A significant proportion of patients may present with Carney's heritable complex of myxomas, spotty pigmentation, and endocrine overactivity. Typically, the lesion is composed of spindled and epithelioid cells displaying abundant intracytoplasmic melanin pigment, together with the formation of psammoma bodies. We report an epithelioid example of this tumor arising in the anterior abdominal wall of a 23-year-old man. A unique feature was a peripheral rim of osseous metaplasia. The tumor was erroneously diagnosed as a metastatic malignant melanoma on initial examination owing to its immunohistochemical coexpression of S100 protein and HMB-45. Psammoma bodies have not to our knowledge been described in melanomas, and their presence serves as a useful clue to the diagnosis of psammomatous melanotic schwannoma.

Synovial sarcoma of the parotid gland. A case report with clinicopathological analysis and review of the literature

Primary sarcomas of the major salivary glands are exceptionally uncommon. Synovial sarcoma is a distinctive neoplasm which usually arises in the extremities in the region of joints. Although synovial sarcomas arising in the head and neck region are well described, tumours actually originating in and around the major salivary glands are exceedingly rare, with few cases reported in the literature. We report a synovial sarcoma in the right parotid gland of a 67-year-old man. The literature pertaining to salivary gland sarcomas and synovial sarcoma of the head and neck region is reviewed.