Primary cutaneous Langerhans cell sarcoma without Birbeck granules: indeterminate cell sarcoma?

An 88-year-old white male presented with a rapidly growing skin nodule on the scalp. Clinically, the nodule did not appear unusual for an ordinary cutaneous neoplasm on sun-exposed skin of an elderly white male. Histopathological examination showed sheet-like epithelioid tumor cell growth with a vaguely nested pattern and frank malignant features, resembling malignant melanoma. However, the tumor cells possessed irregularly convoluted nuclei with nuclear groves, frequent multinucleation and fine vesicular cytoplasm, features highly suggestive of histiocytes. Immunohistochemistry studies showed that the tumor cells were diffusely positive for S-100 protein and CD1a and negative for HMB-45, Melan-A, cytokeratin and CD30. The provisional diagnosis of Langerhans cell sarcoma was thus favored. To confirm this diagnosis, electron microscopic examination was performed. Although classic features of histiocytes were readily identifiable, no Birbeck granules could be found upon a thorough search on repeated sections. These results are indicative of the indeterminate cell nature of the tumor. We propose a diagnosis of primary cutaneous indeterminate cell sarcoma for this unusual histiocytic neoplasm. Current classification of histiocytic neoplasms and differential diagnosis are reviewed.     

Epithelioid sarcoma with angiomatoid features: report of an unusual case arising in an elderly patient within a burn scar

Epithelioid sarcoma (ES) is a rare, aggressive soft tissue tumor with a characteristic predilection for adolescents and young adults, and a tendency to occur on distal extremities. We report a case of ES arising in an 80-year-old woman within a burn scar that histopathologically showed unusual 'angiomatoid' features. The patient presented initially with a solitary nodule on her right wrist arising at the site of a burn scar. Histopathologically, the tumor was composed of a proliferation of relatively bland, epithelioid and spindle cells focally arranged in a nodular pattern around areas of 'geographic' necrosis. In addition, there were prominent foci of hemorrhage and blood-filled spaces as well as tumor cells with intracytoplasmic vacuoles, features suggestive of an angiomatous process. Immunohistochemistry showed positivity of tumor cells for cytokeratins and epithelial membrane antigen (EMA) whereas all vascular markers tested were negative. The overall histopathologic features were consistent with a diagnosis of ES. Follow up showed multiple recurrences arising proximally along the right upper extremity. Our case underlines the clinical and histopathological heterogeneity of ES, emphasizing the unusual occurrence of ES with 'angiomatoid' features in the elderly. In this uncommon setting, this tumor should be especially distinguished from epithelioid hemangioendothelioma and epithelioid angiosarcoma. The significance of development of ES on a healed burn scar is uncertain, but may suggest a possible causal relationship.     

Diagnostic Pitfalls of Merkel Cell Carcinoma and Dramatic Response to Chemotherapy

Merkel cell carcinoma (MCC) is an unusual malignant tumor that arises from neuroendocrine cells with features of epithelial differentiation. We describe a MCC patient with unusual clinical, histopathological, and immunohistochemical features. Although the microscopic, immunohistochemical, and ultrastructural characteristics of MCC have been well defined, diagnostic difficulties remain, particularly in distinguishing it from lymphoma involving the skin, as suggested by our case. This is an unusual case in which dense lymphoid infiltration masked the true tumor. All the immunohistochemical markers of MCC except neuron-specific enolase (NSE) were negative. The dramatic response to primary chemotherapy was also very noteworthy.     

Malignant melanoma of the buttock presenting as a Buruli ulcer

We report an unusual case of malignant melanoma clinically diagnosed as Buruli ulcer, that arose in a 13-year-old boy and presented as an ulcerated, fungating 2 cm mass on the right buttock. The tumor showed the histology and immunohistology of a malignant melanoma. We present this interesting case of malignant melanoma of soft tissue, arising in an unusual location of the body. The tumor presented with clinical features of Buruli ulcer in an area endemic for this disease as well as other tropical ulcerations. Neoplasms, including melanoma, should be considered in the differential diagnosis of Buruli ulcer in endemic areas.     

Lipomatous apocrine mixed tumor of the skin: an unusual giant lesion occurring in the breast

Cutaneous mixed tumors (MTs), also known as chondroid syringomas, usually arise as small nodules in the head and neck region. We describe an unusual case of a giant MT measuring 9 cm in its greatest diameter, occurring as a slowly growing pedunculated mass on the breast of a 74-year-old woman. Although MT may rarely occur outside the head and neck region, to the best of our knowledge, this is the first case described in the breast. Apart this unusual clinical presentation, another intriguing feature of tumor was the histological picture, being composed of an extensive mature fatty stromal component closely intermingling with the epithelial structures. As adipocytes were variable in size and focally showed a lipoblast-like appearance, some tumor areas were reminiscent of a well-differentiated liposarcoma, lipoma-like. Based on the histological features, the term 'lipomatous mixed tumor, apocrine type' was proposed for such a lesion. Histogenetic considerations about the lipomatous stromal component of the tumor are provided.     

A Nevocellular Nevus Consisting mostly of Nevic Corpuscles

A scalp tumor from a 24-year-old male presenting unusual histological finding is described. The tumor was mostly composed of corpuscles resembling Meissner tactile bodies and contained almost no other components. Immunohistochemical studies revealed the tumor cells to be positive for S-100 protein and neuron-specific enolase, so we considered the tumor to be an unusual nevocellular nevus mostly comprised of nevic corpuscles.     

Cutaneous lymphadenoma is distinct from basal cell carcinoma

Background Cutaneous lymphadenoma is a recently recognized unusual tumor. It presents as an indistinct solitary non-ulcerating dermal nodule occuring mostly in the head and neck region of middle aged persons. Its histogenetic definition is controversial and recently it has been proposed that it might represent an unusual inflammatory basal cell carcinoma. We present clinical, hislological and immunohistochemistry data of two cases. For the first time lectin-imrnunohistochemisiry of cutaneous lymphadenoma is reported on. Observations One tumor was located on the eyebrow of a 37 years old, the other on the nose of a 75 years old male patient. Slow growth over years occured. Histology showed biphasic pattern of elongated and angulated lobules with peripheral rim of basaloid cells and central network of lymphohisltocytic cells with preponderance of protein S 100-positive cells. Peanut agglutinin (PNA) did not show peripheral staining around tumor lobules as seen in basal cell carcinoma. Conclusions Clinical and histological features as well as absence of peanut agglutinin staining argue in favor of the distinction of cutaneous lymphadenoma from inflammatory basal cell carcinoma. The former probably represents a benign growth of adnexal origin.     

CHONDROID SYRINGOMA

The characteristic features of chondroid syringoma are reviewed and three cases are presented. The first one showed typical localization and clinical features. The second one was remarkable because of the unusual size of the growth. The third patient had an unusual localization of the tumor on the tip of the nose.     

Cutaneous mixed tumor, eccrine variant: a clinicopathologic and immunohistochemical study of 50 cases, with emphasis on unusual histopathologic features

Mixed tumor, eccrine type, is a rare cutaneous adnexal neoplasm, mostly reported as isolated case reports. A systematic analysis of its histopathologic and immunohistochemical features has not previously been performed on a large series. The purpose of our investigation was to study a large number of cutaneous eccrine mixed tumors so as to fully characterize the entire spectrum of changes in the epithelial and stromal components, with an emphasis on unusual histopathologic features that may represent a diagnostic pitfall. This article reports a light microscopic and immunohistochemical study of 50 cases of eccrine mixed tumor, complemented by a literature review. Our study identified some unusual histopathologic features, thus extending the morphologic spectrum of this neoplasm. These included prominent cribriform areas, clear cell change, pseudorosette structures, prominent osseous metaplasia, and physaliphorous-like cells. Most of these features have not been previously recorded in eccrine mixed tumors and may represent a potential diagnostic pitfall.     

Coexistence of tumor of the follicular infundibulum with an unusual trichilemmal tumor

Tumor of the follicular infundibulum (TFI) is a rare epithelial tumor, and its histogenesis is still somewhat debatable. The diagnosis of TFI cannot currently be made before biopsy, and it is most often misdiagnosed as basal cell carcinoma (BCC). A 78-year-old woman presented to the dermatology clinic with a slightly erythematous nodule surrounded by fine telangiectasia on her right temple. Histopathologic examination of the lesion revealed an epithelial tumor with a plate-like growth pattern as is typical of TFI. In the same specimen, an unusual trichilemmal tumor with multiple epidermal connections was observed adjacent to the foci of TFI. The lobular tumor was composed of a large mass of keratinocytes with pale cytoplasm arranged as sheets and interconnecting ribbons. Several cells with hyperchromatic nuclei and small foci of compact cornification were also noted within the bulk of the tumor. The histopathologic features of the unusual tumor were reminiscent of BCC with trichilemmal differentiation or desmoplastic trichilemmoma.     

Benign pigmented tumor with combined features of seborrheic keratosis and compound nevus

A thirty-six-year-old woman with an unusual benign pigmented tumor of the ankle is presented. Histopathology of the tumor showed combined features of a seborrheic keratosis and a compound nevus. Combined pigmented tumors should be included in the differential diagnosis of pigmented lesions.     

Primitive neuroectodermal tumor in the skin with features of neuroblastoma in an adult patient

A case of primitive neuroectodermal tumor of an 81-year-old man is presented, which was located in the cutis. The occurrence in this age and this superficial location is unusual and raises wide differential diagnostic possibilities. The tumor demonstrated Homer Wright rosettes, was positive for neuron-specific enolase and ultrastructurally revealed neurosecretory granules. These features support the diagnosis of a peripheral neuroblastoma. We discuss the controversy about the terminology of peripheral neuroblastoma vs. neuroepithelioma, as well as the differential diagnosis of these tumors.     

Cellular angiofibroma of the vulva: a clinicopathological study of two cases with documentation of some unusual features and review of the literature

BACKGROUND: Cellular angiofibroma (CA) of the vulva is a recently described condition, whose clinical and pathological features are poorly known. METHODS: We have encountered two cases of this very unusual tumor. Their clinical and pathological features were analyzed and compared to those reported in the literature. RESULTS: Both patients were middle-aged women. In each case, the lesion had the clinical appearance of a vulvar cyst, located in the lateral aspect of the clitoris and the right labium majus, respectively. Microscopically, the lesions were well circumscribed but not truly encapsulated. Both were composed of small spindle cells arranged in short fascicles and mixed up with relatively abundant small- or medium-sized rounded vessels. While mitotic activity was perceptible in both cases, no cellular atypia could be demonstrated. A striking feature seen in one case was the presence of pseudoangiomatous changes in the stroma, similar to those occasionally found in spindle cell lipoma. Phenotypically, the tumor cells consistently expressed vimentin, CD99, and both estrogen and progesterone receptors. A discrete CD34 or smooth muscle actin immunoreactivity was also found in one case. No expression of S-100 protein, Bcl-2 protein, CD117 (c-kit gene product), epithelial membrane antigen, desmin, or h-caldesmon could be demonstrated. CONCLUSION: This study further illustrates that CA of the vulva has distinct clinical and pathologic features that set it apart from the other soft tissue conditions involving this area. However, like many soft tissue neoplasms, this tumor also exhibits some variation in its histological or immunohistochemical features.     

Lupus profundus, indeterminate lymphocytic lobular panniculitis and subcutaneous T-cell lymphoma: a spectrum of subcuticular T-cell lymphoid dyscrasia

INTRODUCTION: The diagnosis and classification of lymphocytic lobular panniculitis (LLP) has historically proven to be a difficult challenge. We encountered 32 cases of primary LLP which could be categorized as: 1) lupus erythematosus profundus (LEP) (19 patients); 2) an indeterminate group termed indeterminate lymphocytic lobular panniculitis (ILLP) (6 patients); and 3) subcutaneous T-cell lymphoma (SCTCL) (7 patients). OBJECTIVE: We attempted to better define the subtypes of LLP by morphologic, phenotypic and genotypic features and to correlate those features to clinical presentation and outcome. METHOD: Skin biopsy material was studied by conventional light microscopy, through immunophenotyping performed on sections from paraffin-embedded, formalin-fixed tissue and in some cases on sections of tissue frozen after receipt in physiological (Michel's) medium, and by polymerase chain reaction single-stranded conformational polymorphism analysis to assess for clonality of T-lymphocytes. Clinical features were correlated to histologic, phenotypic, and genotypic analyses. RESULTS: Patients with LEP had a prior diagnosis of LE or overlying skin changes which light microscopically were characteristic of LE. Patients with ILLP had no concurrent or prior history of LE, no systemic symptoms or cytopenias, and a clinical course not suggestive of lymphoma. Cases of SCTCL showed hemophagocytic syndrome and/or lesional progression with demise attributable to the disease. Lesions in all groups showed proximal extremity predilection. Females predominated in the LEP group. The average age of onset was 38, 40 and 55 years in the LEP, ILLP and SCTCL groups, respectively. Cytopenia was seen in 4 LEP patients; 1 also developed fever. In LEP and ILLP, lesions resolved with hydroxychloroquine and/or steroid therapy, with recurrences following cessation of therapy. In the SCTCL group 4 developed hemophagocytic syndrome, 4 died within 2 years of diagnosis, and 3 went into remission following chemotherapy. The LEP and SCTCL groups manifested histological similarities: dense perieccrine and lobular lymphocytic infiltration, lymphoid atypia, histiocytes with ingested debris, eosinophilic necrosis of the fat lobule and thrombosis. The atypical lymphocytes although pleomorphic did not have a cerebriform morphology. The infiltrate in ILLP had a similar cytomorphology and distribution with variable angioinvasion which in all save one case was of lesser intensity and was not associated with significant fat necrosis or vasculitis. Germinal centers, dermal/subcuticular mucin deposition and an atrophying interface dermatitis with hyperkeratosis and follicular plugging were largely confined to the LEP group. Erythrophagocytosis, characteristic of SCTCL, usually indicated a supervening subcuticular lymphoid dyscrasia when encountered in ILLP and LEP. SCTCL showed a selective loss of CD5 expression with or without diminution in CD7 and monoclonal CD3 expression. Of 4 cases studied, 3 showed a CD8 dominant infiltrate while 2 others exhibited CD56 and CD30 positivity, respectively. All cases of SCTCL with amplifiable DNA showed T-cell clonality. Similar molecular and phenotypic features indicative of subcuticular lymphoid dyscrasia were encountered in cases of LEP and ILLP including a reduction in CD5, CD7, and/or monoclonal CD3 expression, a preponderance of CD8 lymphocytes within the subcutaneous fat and T-cell clonality. These cases showed lymphoid atypia with variable erythrophagocytosis. Cases of phenotypically abnormal and/or clonal LEP showed one or more of local destruction, lesional size progression, fever, and cytopenias, but lesions responded to hydroxychloroquine and/or prednisone therapy and death attributable to panniculitis could not be documented. Cases that were phenotypically normal and without clonality had none of the aforesaid atypical clinical features. CONCLUSION: Lymphoid atypia, erythrophagocytosis, loss of certain pan T-cell markers, a reduced CD4/8 ratio and TCR rearrangement define subcuticular T-cell lymphoid dyscrasia, including a subset of LEP and ILLP. The subcuticular lymphoid infiltrates represent a spectrum of histologic, immunophenotypic, and molecular abnormalities which range from those which are clearly benign to those which are clearly neoplastic, and also encompasses those cases which defy precise classification into the two aforesaid poles.     

“Malignant Spitz Nevus” in a 2-Year-Old Japanese Child

Smith et al. (1989) have reported a variant of Spitz's nevus with histological atypical features. Despite local lymph node metastases, further metastases were not observed. They proposed the name “malignant Spitz nevus” for this variant. A 2-year-old Japanese girl had a large nodule (27 × 17 mm) surrounded by an indurated erythema over the Achilles tendon. Histologically, it proved to be a melanocytic lesion resembling spindle cell and epithelioid cell nevus (Spitz's nevus) with unusual features; the tumor extended deep into the subcutis, and the mitotic figures deep into the tumor, together with prominent lymphatic vessel invasion by melanocytes. Thus the tumor was aptly termed “malignant Spitz nevus”. Flow cytometric analysis of the DNA content revealed a diploid pattern. The child is well 5 years after a wide resection of the tumor. The diploid pattern of the DNA content as well as the good prognosis could support the idea that “malignant Spitz nevus” fits within the spectrum of Spitz's nevus.     

The pathological distinction between "deep penetrating" dermatofibroma and dermatofibrosarcoma protuberans

In selected cases, the clinicopathological distinction between deep penetrating dermatofibroma (DPDF), which involves the subcutis, and dermatofibrosarcoma protuberans (DFSPs) may be challenging. In most instances, attention to the cytological constituency of the lesions and the overall architecture is sufficient to make this separation. DPDF is typified by cellular heterogeneity, including giant cells and lipidized histiocytes; when it extends into the hypodermis, it does so either using the interlobular subcuticular fibrous septa as scaffolds or in the form of broad pushing fronts of tumor. In contrast, DFSP is a cytologically monotypical tumor, which entraps subcutaneous adipocytes diffusely or grows in stratified horizontal plates in the hypodermis. In the minority of cases where conventional morphological analysis of optimal biopsy specimens is diagnostically indeterminate, immunostaining for CD34 and factor XIIIa (FXIIIa) is helpful; it is also often necessary when a poorly-representative sample of the lesion has been obtained by the clinician. Characteristically, DF is diffusely FXIIIa-reactive and CD34-negative, whereas DFSP manifests the converse of those findings. Other markers such as Ki-M1p, mutant p53 protein, and metallothionein may also provide adjuvant diagnostic information in this context, as may the observation of abnormalities in chromosomes 17 and 22 by direct karyotypic analysis.     

Malignant melanoma with osteoclast-like giant cells: an unusual host response: immunohistochemical and ultrastructural study of three cases and literature review

Melanomas with unusual histologic features are very rarely reported in the literature and demonstrate the diversity of melanocytic expression. Three cases of malignant melanoma with osteoclast-like giant cells are reported. Two cases showed undifferentiated malignant cells without melanin pigment and one showed spindled cell morphology. Immunohistochemistry showed that the osteoclast- like giant cells expressed CD68, but not melanocytic markers (HMB45, Melan-A, and S100). Ultrastructural analysis further supports that these cells are reactive histiocytes rather than transformed malignant cells. This suggests they represent an unusual host response, similar to those rarely observed in other neoplasms. Awareness of this entity is important to avoid misdiagnosis of melanoma as a histiocytic tumor. Since only few cases have been reported, greater recognition and documentation may help to evaluate the prognosis of such cases with unusual morphology.     

Solitary Piloleiomyoma with an Unusual Clinical Appearance

We present a 66-year-old man with a solitary piloleiomyoma on the forehead. The lesion had unusual clinical features; it was a crusted and dome-shaped nodule, which exhibited rapid growth. Histology revealed the typical features of piloleiomyoma. The unusual clinical features may have been due to its unique location, in which the downward growth of the tumor was prevented by the underlying frontal bone.     

Localized soft tissue angiomatosis with subsequent development of angiolymphoid hyperplasia with eosinophilia

We report an unusual case of arteriovenous (AV) malformation (localized form of soft tissue angiomatosis): a reaction of angiolymphoid hyperplasia with eosinophilia (ALHE) developed over the lesion of this pre-existing AV malformation. To the best of our knowledge, there is no other report of ALHE in association with a pre-existing bona fide AV malformation. A 71-year-old woman consulted our clinic because a reddish, dome-shaped tumor on her preauricular region, present as a slightly elevated, skin-colored tumor since her childhood, had rapidly enlarged and become more elevated with color change during the preceding two months. The histological features of most of the lesion corresponded to those of soft tissue angiomatosis (localized form). The proliferative vessels underlying the soft tissue angiomatosis streamed out and welled into the dermis with an accompanying prominent inflammatory infiltrate composed of lymphoid cells and eosinophils: these histological features were characteristic of ALHE. The recent abrupt clinical changes in the tumor were considered to represent a reaction to the angiomatosis with development of ALHE.     

Polypoid clear cell acanthoma of the scalp

Clear cell acanthoma (CCA) is a rare, benign epithelial tumor most frequently found on the lower extremities. Its clinical appearance may vary considerably, and cases of multiple lesions have been reported. The diagnosis is made by viewing the characteristic histologic features. This case describes an unusual scalp lesion that clinically and histologically shows unique polypoid features.