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Malakoplakia is an uncommon granulomatous infectious disease that is found primarily in the genito-urinary tract, but may rarely involve the skin. Histologic findings are marked by the presence of foamy macrophages containing basophilic concentric spherules, the Michaelis-Gutman bodies. Micro-organisms are not readily identifiable. Immunostaining with polyclonal anti-mycobacterium bovis (BCG) has been described as a method of identifying bacterial and fungal organisms in situations where organisms may be sparse. We report 2 cases of cutaneous malakoplakia with demonstration of organisms by immunostaining with anti-BCG antibodies. (J Am Acad Dermatol 2000;43:351-4.)

The histogenesis of apocrine and eccrine neoplasms has always interested dermatopathologists. In addition, the histologic differential diagnosis of eccrine carcinoma from metastatic adenocarcinoma is of practical importance. We describe a novel monoclonal antibody IKH-4 which stains the eccrine secretory coil, but not the apocrine secretory segment. Positive staining was observed in eccrine hidradenoma, eccrine poroma, eccrine spiradenoma, papillary eccrine adenoma, eccrine hidrocystoma, syringoma, eccrine carcinoma, and in 1 case of syringocystadenoma papilliferum. Negative staining was observed in apocrine adenocarcinoma, hidradenoma papilliferum, erosive adenomatosis of the nipple, and primary and metastatic adenocarcinomas. IKH-4 antibody was useful in differentiating eccrine from apocrine neoplasms and in differentiating eccrine carcinoma from metastatic adenocarcinomas.

BACKGROUND The clinical appearance of amelanotic lentigo maligna melanoma (ALMM) is quite confusing and usually is not diagnosed prior to histopathologic examination. METHODS We have studied four new patients with ALMM whose correct diagnosis was not obtained from any one clinical finding. We arrived at the final diagnosis in an unexpected way, having had biopsied the lesions for diagnoses other than malignant melanoma. RESULTS ALMM presents as a nonspecific skin lesion with no single indicative characteristic. A search of the literature confirmed our difficulty in making the diagnosis. CONCLUSIONS To diagnose ALMM, one has to be cognizant of this condition and has to consider a constellation of findings that are unusual with melanocytic lesions. Questionable lesions must be biopsied for definitive histopathologic diagnosis. Cancer 1996;77:2052-7.

Six cases of malignant melanoma in children 14 years of age and younger are reported. The six cases were diagnosed among 850,000 consecutive skin biopsy specimens and consultation slides examined within a 32-year period. This series included an infant born with neurocutaneous melanosis, a child with malignant melanoma developing in a large congenital nevus at the age of 13 years, a superficial spreading malignant melanoma, Clark Level III, in a child with many dysplastic nevi, and three cases with primary nodular malignant melanoma, two of which showed histologic features of Spitz nevus. A review of the literature indicates that malignant melanoma in childhood is rare, and no large series have been investigated. It is not known whether the genetic and the environmental factors incriminated in the development of malignant melanoma in adults play a role in childhood melanomas. Data on the incidence of childhood melanoma in the population, the clinical and the histologic variations, and the prognosis are not adequate. A multiinstitutional study is needed to gather a large enough series to provide this information.

• Background.— Deep penetrating nevus is a variant of melanocytic nevi with histologic features that may be alarming and can be mistaken for malignant melanoma. We are presenting a review of the clinical findings and the histologic features of deep penetrating nevus in a series of 14 cases. Observations.— Deep penetrating nevus occurs most commonly over the acral skin of young adults. Clinically, the lesions were diagnosed as pigmented nevus, blue nevus, or malignant melanoma. Histologically, deep penetrating nevus shows a wedge-shaped lesion extending to the deep dermis and the subcutaneous fat tissue. Nests and fascicles of pigmented melanocytes extended deep at the periphery of blood vessels, nerves, and the cutaneous adnexa. Lowgrade cellular atypia is present and mitoses are rare. Conclusions.— Deep penetrating nevus is a variant of benign pigmented nevi with deep dermal and subcutaneous involvement. The pattern should be recognized and differentiated from malignant melanoma. ( Arch Dermatol. 1993;129:328-331)

Benign lymphangioendothelioma is an acquired vascular proliferation clinically appearing as well-demarcated, pink to red-brown macules or plaques. Histologically, numerous endothelial-lined channels are found infiltrating throughout the dermis. Recognition and differentiation from malignant vascular tumors is essential. We report 2 cases of benign lymphangioendothelioma. One of these lesions is unique in its presentation as a subcutaneous nodule. The other is also unusual, as it resolved spontaneously.

Malignant blue nevus is uncommon compared to its benign counterpart and is regarded as a rare form of malignant melanoma. We report the clinical and histological findings in eight cases. Histologically, all eight specimens showed no epidermal involvement and had contained within or were adjacent to portions of blue nevus or cellular blue nevus. Proliferation of bundles of bipolar spindle shaped cells with marked cellular atypia, mitotic figures, foci of necrosis, and inflammatory cell infiltrate were noted. Two of the cases were studied by DNA flow cytometry and the populations of tumor cells were found to be diploid. Two cases have died secondary to metastasis. Although malignant blue nevi may not behave as aggressively as nodular malignant melanoma, they have definite potential to do so and therefore should be removed by wide surgical excision.

Background: Epithelioid cell histiocytomas histologically resemble the intradermal form of Spitz nevus. Objective: We have studied eight patients with epithelioid cell histiocytoma. Methods: In addition to the routine stains, histologic sections were prepared by immunohistochemical techniques for S-100 protein, HMB-45, vimentin, α1-antitrypsin, and common leukocyte antigen. Results: Epithelioid cell histiocytoma is characterized by proliferation of angulated epithelioid cells with abundant eosinophilic cytoplasm. Immunostaining for S-100 protein and HMB-45 were negative. The majority of cells had positive reactions to staining for vimentin and α1-antitrypsin. Approximately 20% to 25% of cells also gave positive reactions to common leukocyte antigen. Conclusion: Immunostainings are useful in the differential diagnosis of epithelioid cell histiocytoma from the intradermal form of Spitz nevus.

Mucin deposition has been reported in a variety of cutaneous neoplasms, including melanocytic nevi. We describe a series of melanocytic nevi with nodular myxoid change.

We report a 3-year-old girl with a rapidly growing, amelanotic, nodular melanoma developing within a burn scar over the dorsal aspect of the left foot. Histologically, the lesion was spindle cell and exhibited lack of maturation, cellular atypia, and scattered mitotic figures. Twenty five percent of the tumor cells were positive for proliferating cell nuclear antigen by immunohistochemical stain. A left inguinal lymph node was also positive for regional metastasis. The child died with disseminated metastases 13 months after the lesion was removed.

BACKGROUND Spindle cell lipoma is an unusual and histologically distinctive form of lipoma occurring primarily in older individuals. OBJECTIVE The dermatologic surgeon and pathologist should be familiar with this variant of lipoma. METHODS We are reporting two cases of spindle cell lipomas with the results of histologic examination with special stains and immunohistochemical studies. RESULTS The neoplasms consisted of lobulated masses of mature adipose tissue with areas of spindle cell proliferation. There was strong positive staining with antibodies for vimentin within the areas of spindle cell proliferation. One of the cases is unusual in that multiple lesions are occurring in a young patient. CONCLUSION Recognition of the histologic pattern is important in distinguishing the benign spindle cell lipoma from, the malignant liposarcoma.

BACKGROUND: Vitiligo is a relatively common skin disease characterised by development of patchy depigmented macules. A comparative ultrastructural study was undertaken between early developing (2-6 months duration) and long standing (1-5 years duration) lesions of vitiligo in a series of ten patients. METHODS: Skin biopsy specimens from the ten patients were fixed, stained, and examined under an electron microscope. RESULTS: No melanocytes were found in the sections taken from long standing lesions. The sections from early lesions showed junctional melanocytes exhibiting various cellular abnormalities. The epidermal keratinocytes were normal in all sections; however, some sections from the periphery of early lesions exhibited minor degenerative changes. CONCLUSIONS: We can assume that because of the absence of melanocytes in long standing lesions, repigmentation may occur only from the melanocytic reservoir in the hair follicles. Repigmentation may also occur in lesions of short duration by reactivation of melanocytes present in the area, so an attempt should be made to treat vitiligo lesions in their early stage.

Background: The cutaneous lesions in chronic lupoid leishmaniasis resemble those of lupus vulgaris, both clinically and histologically. The differential diagnosis is difficult and may depend on the detection of a few Leishmania amastigotes in the histologic sections, the growth of the promastigotes in cultures, or the identification of amastigotes by other techniques. Polymerase chain reaction was used to detect Leishmania amastigote DNA in tissue samples obtained from 65 patients with chronic lupoid leismaniasis, and the results were confirmed by Southern blot analysis. Observations: The histologic findings of a predominantly epithelioid cell granuloma surrounded by lymphocytic infiltrate in chronic lupoid leishmaniasis are very similar to those observed in lupus vulgaris. Extensive histologic examination of the sections in this series revealed occasional macrophages containing a few amastigotes in only 12 cases. Cultures in NNN medium yielded Leishmania promastigotes in 20 cases. Polymerase chain reaction studies using a Leishmania-specific primer identified Leishmania DNA in 30 of 63 cases, and those using a Mycobacterium tuberculosis primer were found to be negative for mycobacteria in 47 cases tested, including 11 cases with a positive tuberculin skin reaction. Conclusions: The histologic findings in chronic lupoid leishmaniasis resemble those of lupus vulgaris. Polymerase chain reaction studies were useful in identifying amastigotes in 30 (47.6%) of 63 cases. This study confirms the presence of DNA molecules of Leishmania amastigotes in samples of formalin-fixed, paraffin-embedded granulomatous tissue obtained from patients with chronic lupoid leishmaniasis. (Arch Dermatol. 1996;132:198-202)

We report twelve cases with a distinctive form of adnexal carcinoma occurring most commonly over the head and neck of relatively old individuals. The growth was single in all cases, deep dermal in location, and consisted of massive proliferation of small basaloid cells with only occasional connection with the surface epidermis. The basaloid tumor masses showed only a few areas of palisading of their outer cell nuclei and occasional retraction space formation. The neoplasm revealed scattered areas of trichilemmal and epidermoid keratinization, foci of sebaceous, and areas of sweat ductal differentiation indicating participation of various components of the pilary complex.

Suppressor oncogene p53 is expressed more frequently in the nodular portion than the superficial spreading portion of the same melanoma. PCNA expression follows the same pattern but it is strongly expressed already in the superficial spreading portion. CD34 is found to label dermatofibrosarcoma protuberans. There is the mixture of negative strands but the immunostains are predominantly positive in the three cases studied. Neurogenic tumors are reactive but the intensity of staining is only moderate. Fibrous histiocytoma, dermatofibroma and other fibrohistiocytic tumors are non-reactive. CD34 is expressed in the outer root sheath of hair follicle below the sebaceous gland level. A case of piloepidermal cyst is CD34 positive. CD34 is expressed in vascular endothelial cells; not only hemangiomas but also lymphangiosarcoma is CD34 positive. A case of indeterminate cell histiocytosis following scabies and superficial variant of clear cell sarcoma are discussed as examples of new entities.

A comparative histopathologic study is made between the hypopigmented and hyperpigmented skin lesions of pityriasis versicolor and normal skin areas utilizing histochemical stains and electron microscopy. There were no differences found between the population of Dopa-positive melanocytes within the hypopigmented and hyperpigmented lesions and the normal skin areas. The total epidermal pigmentation was diminished in hypopigmented lesions. The keratin layer was found to be significantly thicker in hyperpigmented lesions and contained more organisms. In hypopigmented lesions, melanocytes contained fewer and smaller melanosomes and exhibited signs of degenerative cellular changes.

We have reviewed a series of 585 scalp biopsies taken for histologic evaluation of hair loss and have looked for syringoma-like eccrine sweat duct proliferation. This feature was found in 6 specimens with scarring alopecia and one each with alopecia areata and female-pattern alopecia. Syringoma-like sweat duct proliferation appears to play no role in the etiology of hair loss.

background . Basal cell epithelioma is a tumor arising from a pluripotential cell found within the basal cell layer of the epidermis or various appendageal structures. objective . We report two cases of basal cell epithelioma arising from the wall of an epidermoid cyst. methods AND RESULTS. Review of our files produced two cases of basal cell epithelioma arising from a cyst wall. conclusions . Basal cell epithelioma arising from the wall of an epidermoid cyst is rare. Examination of all cysts removed surgically is important as not to overlook this possibility and to allow close follow-up for potential recurrence.

Objective: To elucidate the geographic and genospecific association of Borrelia with morphea and lichen sclerosus et atrophicus (LSA). Design: The association of Borrelia burgdorferi with morphea and LSA has been reported, but is still controversial. We conducted a retrospective survey of Borrelia DNA in skin biopsy specimens. Settings: The samples were collected from the outpatient clinic of university hospitals and a dermatopathology laboratory. Patients: Skin biopsy specimens (19 morphea and 34 LSA) were obtained from patients in the United States, Japan, and Germany. DNA samples were subjected to amplification with polymerase chain reaction for B burg-dorferi flagellin gene, and for the genotype-specific detection of B burgdorferi sensu stricto, Borrelia garinii , and Borrelia afzelii . Results: Five cases of morphea and 2 cases of LSA in Germany and Japan yielded positive signals for B garinii or B afzelii , the European species. None of the American samples were positive for Borrelia polymerase chain reaction. Borrelia burgdorferi sensu stricto was not detected in any of the specimens. Conclusion: Morphea and LSA in Germany and Japan can be related with European genotypes of Borrelia. Arch Dermatol. 1997;133:41-44

BACKGROUND. Spindle cell lipoma is an unusual and histologically distinctive form of lipoma occurring primarily in older individuals. OBJECTIVE. The dermatologic surgeon and pathologist should be familiar with this variant of lipoma. METHODS. We are reporting two cases of spindle cell lipomas with the results of histologic examination with special stains and immunohistochemical studies. RESULTS. The neoplasms consisted of lobulated masses of mature adipose tissue with areas of spindle cell proliferation. There was strong positive staining with antibodies for vimentin within the areas of spindle cell proliferation. One of the cases is unusual in that multiple lesions are occurring in a young patient. CONCLUSION. Recognition of the histologic pattern is important in distinguishing the benign spindle cell lipoma from the malignant liposarcoma. Dermatol Surg 1995 ;21 :796-798.

After the outburst of the acquired immunodeficiency syndrome (AIDS), AIDS-related Kaposi's sarcoma (AIDS-KS) has been commonly found among homosexual AIDS patients infected with human immunodeficiency virus type 1. 1 Recently, a causative role of human papillomavirus (HPV) type 16 in KS was suggested, 2 although contradictory results were also reported. 3 To elucidate the role of HIV-1 and HPV-16 in KS, we performed polymerase chain reaction-based analyses with DNA extracted from classic KS, AIDS-KS, and primary culture of AIDS-KS. Observations. DNA samples were extracted from formalin-fixed, paraffin-embedded tissue sections obtained from biopsy specimens from 15 classic KS cases from 1976 through 1979 and seven cases of AIDS-KS seen in 1991. Each section was cut with a disposable new razor blade and the epidermis was removed. Before the amplification of viral DNA, the integrity of each sample was checked with β-globin gene amplification, and negative samples of nine classic KS cases

To the Editor: In the September 1990 issue ofthe JOURNAL a brief communication was published by Drs. O. Stanton and P. E. LeBoit suggesting that fixation in an alcohol-based preservative solution (Omnifix) produced sclerodermoid artifactual changes in the skin biopsy specimen ofone case (1990;23:513). The authors gave no mention or references to the previous publications concerning this form of artifactual findings. We have previously described scleroderma-like artifactual tissue changes occurring when the pedicle of punch biopsy specimens was squeezed by forceps during the biopsy procedure. l , 2 We have not observed this type of artifact when tissue is surgically excised by a knife. In addition, we have used alcohol fixation (70% ethyl alcohol) in our laboratory for more than two decades with the purpose of preventing freezing artifact when the biopsy specimens are placed into a mailbox during the northern cold winter season. We do not observe scleroderma-like artifactual changes in our routinely alcohol-fixed tissue sections. Drs. Stanton and LeBoit should investigateother factors besides alcohol fixation for the cause of changes observed in their case.

We report a patient with aneurysmal (angiomatoid) fibrous histiocytoma manifested clinically as a single firm subcutaneous nodule, diagnosed as an epithelial cyst. Histologically, the growth showed massive histiocytic proliferation and areas with a vascular component. The lesion was histologically mistaken for Kaposi's sarcoma.

Four patterns of proliferation of eccrine sweat ducts were observed in examination of routine histologic sections of diseases of the skin. Sweat duct proliferation is a reactive process and must be differentiated from a benign adnexal neoplasm or an infiltrating malignant one.

We used Rhodamin B stain in sections of normal skin, benign and malignant epithelial tumors and dermatoses. Keratin staining was uneven and showed variation in different lesions. While tricho-hyalin of the anagen hair follicle stained with intensity, keratohyalin granules failed to show similar reaction.

Malignant transformation occurred in pre-existing sweat gland tumors in 7 patients. Three lesions showed an histologic pattern of eccrine spiradenoma, 2 eccrine poroma, one cylindroma and one papillary eccrine adenoma. Malignant transformation was histologically characterized by the presence of solid tumor areas populated with large cells having irregularly shaped nuclei and mitotic figures. There were multiple foci of squamous metaplasia, areas of loss of basement membrane and invasion of the surrounding connective tissue.

2,126 consecutively diagnosed basal cell epitheliomas (BCE) were studied for unusual sites of occurrence. A small number of BCE occurred in unexpected locations and presented some difficulty in clinical diagnosis.

Skin specimens from five mummies were examined histologically. The specimens ranged in age from 2,000 to 3,200 years. Material from two mummies had carbonized and showed only amorphous debris. The histology of the three remaining skin fragments retained surprising histologic architectural detail. One specimen obtained from the sole of the foot was compatible with a callus.

Ultrastructural changes in specimens removed from Bowen's diseased genital areas of five patients are described, and a comparison is made with the tissue from the surrounding normal skin. Electron microscopic findings in Bowen's disease include an advanced dyskeratosis, acantholysis due to dissolution of desmosomal-tonofilament complexes, enlarged nuclei and nucleoli, increased polysome populations, mitochondrial alterations and nuclear inclusions. The basement membrane remains intact. Occasionally, atypical cells are undergoing cytolysis and are engulfed and phagocytized by the neighboring keratinocytes (apoptosis). The normal epithelium at the periphery of the lesion exhibits only a minimal degree of ultrastructural change.

We report two cases of eccrine syringofibroadenoma. Both patients had a large, solitary hyperkeratotic nodular lesion over the extremities. Histologic sections showed spongelike masses of small cuboidal acrosyringeal cells. Fibrovascular connective tissue stroma resembling premalignant fibroepithelial tumor of Pinkus filled the spaces between the masses.

We are reporting a case of keratosis lichenoides chronica. This is a chronic dermatosis characterized by seborrheic dermatitis—like facial eruption and purplish papulonodular lesions of the extremities. These lesions sometimes show linear configuration. Histologic changes include features of a chronic and lichenified dermatitis and lichen planus.

A long-standing tumor of scalp is reported characterized histologically by extensive proliferation of pilar epithelium made up exclusively of cells with small round nuclei and clear cytoplasms containing glycogen granules. The tumor epithelium showed no tendency for keratinization and no cytologic atypia. The growth, however, appeared aggressive and replaced the entire thickness of the dermis and extended into the subcutaneous fat tissue.

This report concerns a series of eight patients with large basal cell epitheliomas that occurred on sunlight-protected areas of the trunk. Histologically, the neoplasms exhibited highly “invasive” features and were complicated by recurrences. Five years after removal of one of the neoplasms by surgical excision, regional lymphatic metastasis occurred. This was followed by distant metastases to the lung and pelvic bone.

Pigmented follicular cysts are newly described cutaneous cysts with characteristic histology. They are usually single pigmented lesions occurring in men between 20 and 63 years of age that often are mistaken for nevi. The eighth case of this newly described cyst is presented; a brief review of epithelial cysts and how they differ from pigmented follicular cysts also is reported.

The occasional occurrences of combined hamartomas composed of nevus cell nevi and adnexal tumors are not chance happenings. Pigmented nevi are malformations consisting of nevus cells together with various connective tissue and epithelial components. The proliferation of these components results in the combined malformations, whose occurrence, we believe, is more supporting evidence for the idea that pigmented nevi may have other components besides nevus cells.

The generality of benign epithelial neoplasias of follicular origin or with differentiation toward follicular structures is briefly reviewed. Recently delineated examples of this group are more extensively discussed.

A father and his son were seen because of multiple wartlike lesions on their fingers and palms. On histologic examination, these lesions showed changes compatible with vascular fibromas, myxoid fibromas, and, in a few instances, verruca vulgaris. We are not aware of reports of similar cases in the dermatologic literature.

Extensive macrophagic pigmentation may occur in benign cellular nevi extending deep into the corium or spreading peripherally to give the clinical impression of a blue nevus or a malignant melanoma. Eight examples of this type are reported.

One of the two types of complications that may occur with organoid nevus (nevus sebaceus) is the category of brain malformations and seizure disorders. The second type is the late occurrence of various epithelial growths that are usually observed to develop in long-standing organoid nevi. Among these later-occurring lesions, we are describing the occurrence of proliferating trichilemmal cysts in association with organoid nevi.

During the past 2 years we have studied eighty-nine biopsy specimens from nineteen patients with Cowden's syndrome. Among fifty-three facial lesions, twenty-nine were trichilemmomas. Twenty-three of the others were consistent with trichilemmoma, showed a non-specific benign verrucous acanthoma, or were not diagnostic; one was a blue naevus. All fourteen oral mucosal biopsy specimens were benign fibromas. Nineteen of twenty-two biopsy specimens from the hands and feet showed the pattern of benign keratosis. Multiple trichilemmomas were found in all patients with Cowden's syndrome, but at times several biopsy specimens were required before a diagnostic picture was uncovered. All patients with multiple facial trichilemmomas were found to have Cowden's syndrome. The combination of multiple facial trichilemmomas, oral fibromas, and benign acral keratoses enables one to diagnose Cowden's syndrome at a stage before serious internal complications develop.

A review is made of superficial fibrous tumors of childhood and differences between the pattern of fibrous tumor proliferation in children and adults are discussed. The fibrous tumors that occur specifically in childhood and infancy include recurring digital fibrous tumor, juvenile aponeurotic fibroma (cartilage analogue of fibromatosis), juvenile hyalin fibromatosis, fibrous hamartoma of infancy, congenital fibromatosis and fibromatosis colli (Torticollis). Palmoplantar fibromatosis and fibrosarcoma may appear in all ages. Dupuytren contracture, however, is not usually observed early in life. Similarly, the histiocytomas and dermatofibromas which are the most common fibrous tumors of adults are extremely rare in childhood.

Five patients with mclanoacanthonia are reported. The skin lesions consisted of a single, round plaque measuring several centimeters in diameter. Histologic findings were characterized by formation within an acanthotic epidermis, of many islands of small basaloid cells and highly dendritic melanocytes. Electron microscopic examination of one lesion revealed a disturbance of melanin transfer from the highly dendritic melanocytes to the neighboring keratinoeytes.

The mouse monoclonal antibody AFH1 was produced using formalin-fixed, sham paraffin-embedded human melanoma cell culture line A375 as immunogen. Reactivity of this antibody was assessed by immunohistochemical techniques against formalin- or acid alcohol-fixed paraffin-embedded tissue as well as formalin- or acid alcohol-fixed unembedded lesions. Ninety-seven nevomelanocytic lesions, neurofibromas, epithelial lesions, and a plasmacellular infiltrate were evaluated. AFH 1 was immunoreactive on 54 of 55 nevocytic lesions (98.2%), 15 of 16 primary melanomas (93.7%), a lentigo maligna, and nests in 21 of 21 dysplastic nevi (100%). Of 100 consecutive basal melanocytes of intraepidermal melanoma cells counted in each lesion, mean AFH1 immunoreactivity for nonnested basal melanocytes in nevocellular nevi was 3.8%; for dysplastic nevi, 13.8%; and for intraepidermal melanoma cells, 78.0%. When nonnested basal melanocytes were subdivided into cytologically normal and abnormal cell groups, AFH1 immunoreactivity was 9.4% and 72.6%, respectively. AFH1 recognition of the lentiginous portion of dysplastic nevi corresponds statistically to the appearance of abnormal melanocyte cytology, nest formation, or both. Using 50% immunoreactive nonnested melanocytes as the criterion, AFH1 seems to distinguish primary melanoma from dysplastic nevi with a sensitivity of 93.8% and a specificity of 95.8%.

We are reporting seven cases with nevus lipomatosus cutaneus superficialis. A review of the literature indicates that this is a relatively rare type of connective tissue nevus with little more than 50 cases recorded. Localization of the cutaneous nodular lesions over the upper thigh and buttock and histologic findings of fat lobules within the substance of the nevoid malformation differentiate these lesions from other varieties of the connective tissue nevi.