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Histopathologic study of Koenen tumors
Dermatopatholoou I I
I I
Histopathologic study of Koenen tumors Are they different from acquired digital fibrokeratoma ? Andr6 Kint, M.D.,* and Robert Baran, M.D.**
Ghent, Belgium, and Cannes, France Fifteen periungual fibromas from nine patients were studied histologically. The lesions were elongated. Capillaries were found in the distal part surrounded by thin collagen bundles whereas the proximal part was made up of dense, closely packed fibers. The epidermis covering the tumor appeared to be connected with the nail fold. The dense collagen of the lesion faded into the normal structure of the cutis of the proximal nail fold. Periungual fibromas can be subdivided into (1) fibrokeratomas originating from the dermal connective tissue and (2) fibrokeratomas originating from the proximal nail fold. (J AM ACAD DERMATOL1988;18:369-72.)
Tumors of Koenen or periungual fibromas are observed in approximately 50% of patients with tuberous sclerosis of Bourneville. ~'2 They are pedunculated, flesh-colored periungual tumors, with a pointed hyperkeratotic extremity, which develop underneath the proximal nail fold and rest on the nail plate. The periungual fibroma appears most often at or after puberty. The tumor is considered by most authors to be a connective tissue proliferation, containing dilated capillaries 3 and sometimes arteriovenous anastomoses.4'5 However, Nickel and Reed 2 describe a neural or glial appearance with stellate-shaped and small giant cells, but according to Knoth and Meyhrfer, ~ nerves are not particularly numerous. On the other hand, Kawamura et al 6 have described the tumors as being composed of special tissue, containing many cells, numerous capillaries, but no elastin; they did not find neural alterations. Yasuki 7 considers the histologic picture of the periungual fibroma as different from that of the acquired periungual fibrokeratoma, but for Hornstein and Weidner 8 and Pirrard and Lapi~re, 9 the periungual fibroma is a
., ;/~
Fig. 1. Periungual fibroma resting in a depression of the nail plate. nevus of the reticular connective tissue that cannot be differentiated histologically from the acquired digital fibrokeratoma; it contains almost no elastin and shows sclerosis of the connective tissue with telangiectasis. 8 In this investigation the structure of these tumors has been studied to determine their origin. MATERIAL
From the Clinic of Dermatology, Akademisch Ziekenhuis, University of Ghent,* and the Dermatologieat Unit, Centre Hospitalier, Cannes.** Reprint requests to: Prof. Dr. A. Kint, Clinic of Dermatology, University of Ghent, De Pintelaan 185, B-9000 Ghent/Belgium.
The basis of this study comprised I5 tumors from nine patients. For histologic examination, the tissues were fixed in 10% formalin or alcohol-formaldehydeacetic (AFA) (alcohol 94%, 80 ml; fomaaldehyde 40%,
369
3'70
Kint and Baran
Journal of the American Academy of Dermatology
Fig. 2. a, The apex of the horny layer is hyperkeratotic. The distal part of the tumor contains capillaries and thin collagen fibers, b, The core of the tumor is composed of dense and closely packed collagen bundles, oriented in the longitudinal axis of the lesion. 15 ml; and acetic acid 100%, 5 ml). Paraffin-embedded sections were stained routinely with hematoxylin and eosin, Masson's trichrome stain, periodic acid-Schiff (PAS), Alcian blue, toluidine blue, and orcein for the study of the elastic fibers. Clinical data. Of the nine patients, two were men and seven women. The ages of the patients varied from 17 to 54 years; the average age was 38.3 years. Two lesions were located on the dorsal aspect of the fingernails and 13 on the toenails. All the periungual fibromas were excrescences emerging from beneath the proximal nail fold; the extremity was hyperkeratotic and the le-
sions often rested in a depression of the nail plate (Fig. I). Histopathology. The lesions were elongated and covered with a slightly acanthotic epidermis; at the apex the horny layer was often thickened. The structure of the distal part of the lesion differed from that of the core of the lesion. The former contained many capillaries, surrounded by thin collagen fibers (Fig. 2, a), whereas the core was made up of dense, closely packed collagen bundles, mostly oriented in the longitudinal axis of the lesion and among which the occurrence of capillaries was rare (Fig. 2, b). Between the collagen
Volume 18 Number 2, Part 1 February 1988
K o e n e n tumors
371
Fig. 3. The epidermis covering the tumor is connected with the nail fold. bundles fibroblasts with fusiform nuclei were found. No elastic fibers nor neural structures were observed in the tumors. In serial sections of three lesions that were excised totally, the epidermis covering the tumor appeared to be connected with the nail fold (Fig. 3); in the other lesions, the proximal part of the epidermis was lacking. In all of the tumors, the dense collagen of the core faded into the normal structures of the cutis of the proximal nail fold, which also contained eccrine sweat glands, neural filaments, and sensory bodies. DISCUSSION In the Koenen tumors we examined, two parts could be distinguished: a small distal part with loose collagen and many blood vessels and a larger proximal part built up of dense collagen bundles and fewer capillaries. The histologic structure of the apex was similar to that described for these tumors by Klingbeil 4 and Kawamura et al, 6 whereas the core of the lesion corresponded to the descriptions of Hornstein and Weidner 8 and Yasuki 7 and resembled the histology of the acquired digital fibrokeratoma type I. j~ No tumor had "neural or glial appearance" as was stated by Nickel and Reed, z nor could arteriovenous anastomoses 5 be found. It thus appears likely that the Koenen tumor can be considered a particular type of fibrokeratoma that, according to Pi6rard and Lapi6re, 9 originates from the reticular dermis. Yasuki, 7 who studied the acquired periungual fibrokeratoma, distinguishes a type 1 lesion involv-
ing the nail plate and a type 2 lesion in which the tumor is derived from the periungual area; he considers that, like the acquired periungual fibrokeratoma, the periungual fibroma can be classified according to the topographic anatomy of the nail. In his opinion the periungual fibroma corresponds to the type I-acquired pefiungual fibrokeratoma and could be derived from the ventral aspect of the proximal nail fold, from the dermis beneath the matrix, or from the nail bed. In our material only one tumor type was observed--namely, a first-type lesion originating from the connective tissue located above the matrix. No lesions originated from the dermis beneath the matrix nor f r o m the nail bed. If the pefiungual fibroma is considered a particular type of fibrokeratoma, this tumor can be subdivided according to its clinical appearance, its location, and its origin into the following classifications: 1. Fibrokeratomas originating from the dermal connective tissue. These are posttraumatic or appear spontaneously and are located on the fingers (acquired digital fibrokeratoma). 2. Fibrokeratomas originating from the proximal nail fold or the surrounding connective tissue. They are located in the nail fold and can be congenital (tuberous sclerosis) or acquired (for example, garlic-clove fibroma). The close connection of the periungual fibroma with the proximal nail fold explains its particular clinical appearance.
372
Journal of the American Academy of Dermatology
Kint and Baran
W e thank Dr. Verret (Angers) for p r o v i d i n g o n e of the tumors u s e d in this study.
REFERENCES 1. Baran R, Dawber RPR. Diseases of the nails and their management. Oxford, England: Blackwell Scientific Publications, 1984:410-1. 2. Nickel WR, Reed WB. Tuberous sclerosis. Special reference to the microscopic alterations in the cutaneous hamartomas. Arch Dermatol 1962;85:209-24. 3. Rogers SR. Dermatologic manifestations, ha: Gomez MR, ed. Tuberous sclerosis. N e w York: Raven Press, 1979:114. 4. Klingbeil M. Ausgedehnte Fibromatosis sub- und periungualis bei Morbus Pringle. I--Iautarzt 1956;7: 360-2.
5. Knoth W, Meyh6fer W. Zur Nosologie des Adenoma sebaceum Typ Balzer, der Koenenschen Tumoren und des Morbus Bourneville-Pringle. Hautarzt 1957;8: 359-66. 6. Kawamura T, Nakauchi Y, Mori S. Beitrag zur Pathogenese der Bourneville-Pringleschen Phakomatose. Hautarzt 1964;15:476-82. 7. Yasuki Y. acquired periungual fibrokeratoma. A proposal for classification of periungual fibrous lesions. J Dermatol (Tokyo) 1985;12:349-56. 8. Hornstein OP, Weidner F. Tumoren der Haut. In: Schnyder UW. Histopathologie der Haut, tell 2: Stoffweckselkrankheiten und Tumoren. Bedim Springer, 1979:250. 9. PiCrard GE, Lapi~re CM. Nevi of connective tissue. A reappraisal of their classification. Am J Dermatopathol 1985;7:325-33. 10. Kint A, Baran R, De Keyser H. Acquired (digital) fibrokeratoma. J AM ACAD DE~A'rOL 1985;12:816-21.
ABSTRACTS
Cutaneous blastomycosis as a complication of transthoraclc needle aspiration Carter RR 3d, Wilson JP, Turner HR, et al. Chest 1987;91:917-8
cyte reactions showed similar interference by laser irradiation. The authors speculate that the hazards of low-energy laser irradiation to humans may be similar to the subtle modifications in biologic function they note in vitro. Jay A. Levin, M,D.
Implantation into the skin of the yeast form of blastomycoses reliably will cause a cutaneous lesion. Philip C. Anderson, M.D.
Two-step photoactivation of porphyrins with nanosecond red pulses
Epidemiologic study of canine blastomycosis in Wisconsin Archer JR, Trainer DO, Schell RF. J Am Vet Med Assoc 1987;190:1292-5
The recent epidemic of blastomycosis in Wisconsin has not been limited to humans. From 1980-1982, 200 cases of blastomycosis in dogs came under study. Cough, lethargy, and loss of weight are the usual early signs. Wherever canine hlastomycosis occurs humans will become infected, probably both groups from the soil, not from each other. Philip C. Anderson, M.D. Laser modulation of human immune system: inhibition of lymphocyte proliferation by a gallium-arsenide laser at low energy Ohta A, Abergel RP, Uitto J. Lasers in Surg 1987;7:199201 Cultured human lymphocytes were subjected to low energy gallium-arsenide laser irradiation. Cell proliferation measured by tdtiated thymidine was markedly inhibited by energy fluence as low as 10.85 mjoules/em2, as was mitogenic proliferation after pb.ytohemagiuttinin stimulation. At this energy fluence the viability of the ceils was unaffected. The functional immune response of human lymphocytes in response to antigen stimulation by one-way mixed lympho-
Andreoni A, Cubeddu R, Suelto O, Canti G, Ricci L, Smilquiavitchious V. Lasers Life Sci 1987;1:213-8 Laser-induced photochemotherapy for malignancies holds much promise for ouercoming limitations in the formation of cytotoxic photoproducts from porphyrias. Unfortunately, difficulties remain. The authors overcome problems with low energy and poor depth of penetration by using two pulsed excimer pumped-dye lasers tuned at 631 and 700 nm. The two-step excitation of hematoporphyrin derivative then allowed a higher ceil killing rate of murine fibrosarcoma tumor. This new technique would allow penetration of large tumor masses as well as superficial lesions. Jay A. Levin, M.D.
Genetic and diagnostic significance of HLA markers in sarcoidosis (German text) Nowack D, Goebel KM. Schweiz Med Wchnschr 1986;116:1479-80 Sixty-seven patients with histopathologically proved sarcoidosis were tested for human lymphocyte antigen (HLA) markers. The only marker that was significantly increased was HLA-DR5 (49.3% for sarcnid patients versus 21% in controls). HLA-DR5 carriers have a risk of developing sarcoidosis 35 times greater than patients without this marker. Yehudi M. Felman, M.D.
I I
Histopathologic study of Koenen tumors Are they different from acquired digital fibrokeratoma ? Andr6 Kint, M.D.,* and Robert Baran, M.D.**
Ghent, Belgium, and Cannes, France Fifteen periungual fibromas from nine patients were studied histologically. The lesions were elongated. Capillaries were found in the distal part surrounded by thin collagen bundles whereas the proximal part was made up of dense, closely packed fibers. The epidermis covering the tumor appeared to be connected with the nail fold. The dense collagen of the lesion faded into the normal structure of the cutis of the proximal nail fold. Periungual fibromas can be subdivided into (1) fibrokeratomas originating from the dermal connective tissue and (2) fibrokeratomas originating from the proximal nail fold. (J AM ACAD DERMATOL1988;18:369-72.)
Tumors of Koenen or periungual fibromas are observed in approximately 50% of patients with tuberous sclerosis of Bourneville. ~'2 They are pedunculated, flesh-colored periungual tumors, with a pointed hyperkeratotic extremity, which develop underneath the proximal nail fold and rest on the nail plate. The periungual fibroma appears most often at or after puberty. The tumor is considered by most authors to be a connective tissue proliferation, containing dilated capillaries 3 and sometimes arteriovenous anastomoses.4'5 However, Nickel and Reed 2 describe a neural or glial appearance with stellate-shaped and small giant cells, but according to Knoth and Meyhrfer, ~ nerves are not particularly numerous. On the other hand, Kawamura et al 6 have described the tumors as being composed of special tissue, containing many cells, numerous capillaries, but no elastin; they did not find neural alterations. Yasuki 7 considers the histologic picture of the periungual fibroma as different from that of the acquired periungual fibrokeratoma, but for Hornstein and Weidner 8 and Pirrard and Lapi~re, 9 the periungual fibroma is a
., ;/~
Fig. 1. Periungual fibroma resting in a depression of the nail plate. nevus of the reticular connective tissue that cannot be differentiated histologically from the acquired digital fibrokeratoma; it contains almost no elastin and shows sclerosis of the connective tissue with telangiectasis. 8 In this investigation the structure of these tumors has been studied to determine their origin. MATERIAL
From the Clinic of Dermatology, Akademisch Ziekenhuis, University of Ghent,* and the Dermatologieat Unit, Centre Hospitalier, Cannes.** Reprint requests to: Prof. Dr. A. Kint, Clinic of Dermatology, University of Ghent, De Pintelaan 185, B-9000 Ghent/Belgium.
The basis of this study comprised I5 tumors from nine patients. For histologic examination, the tissues were fixed in 10% formalin or alcohol-formaldehydeacetic (AFA) (alcohol 94%, 80 ml; fomaaldehyde 40%,
369
3'70
Kint and Baran
Journal of the American Academy of Dermatology
Fig. 2. a, The apex of the horny layer is hyperkeratotic. The distal part of the tumor contains capillaries and thin collagen fibers, b, The core of the tumor is composed of dense and closely packed collagen bundles, oriented in the longitudinal axis of the lesion. 15 ml; and acetic acid 100%, 5 ml). Paraffin-embedded sections were stained routinely with hematoxylin and eosin, Masson's trichrome stain, periodic acid-Schiff (PAS), Alcian blue, toluidine blue, and orcein for the study of the elastic fibers. Clinical data. Of the nine patients, two were men and seven women. The ages of the patients varied from 17 to 54 years; the average age was 38.3 years. Two lesions were located on the dorsal aspect of the fingernails and 13 on the toenails. All the periungual fibromas were excrescences emerging from beneath the proximal nail fold; the extremity was hyperkeratotic and the le-
sions often rested in a depression of the nail plate (Fig. I). Histopathology. The lesions were elongated and covered with a slightly acanthotic epidermis; at the apex the horny layer was often thickened. The structure of the distal part of the lesion differed from that of the core of the lesion. The former contained many capillaries, surrounded by thin collagen fibers (Fig. 2, a), whereas the core was made up of dense, closely packed collagen bundles, mostly oriented in the longitudinal axis of the lesion and among which the occurrence of capillaries was rare (Fig. 2, b). Between the collagen
Volume 18 Number 2, Part 1 February 1988
K o e n e n tumors
371
Fig. 3. The epidermis covering the tumor is connected with the nail fold. bundles fibroblasts with fusiform nuclei were found. No elastic fibers nor neural structures were observed in the tumors. In serial sections of three lesions that were excised totally, the epidermis covering the tumor appeared to be connected with the nail fold (Fig. 3); in the other lesions, the proximal part of the epidermis was lacking. In all of the tumors, the dense collagen of the core faded into the normal structures of the cutis of the proximal nail fold, which also contained eccrine sweat glands, neural filaments, and sensory bodies. DISCUSSION In the Koenen tumors we examined, two parts could be distinguished: a small distal part with loose collagen and many blood vessels and a larger proximal part built up of dense collagen bundles and fewer capillaries. The histologic structure of the apex was similar to that described for these tumors by Klingbeil 4 and Kawamura et al, 6 whereas the core of the lesion corresponded to the descriptions of Hornstein and Weidner 8 and Yasuki 7 and resembled the histology of the acquired digital fibrokeratoma type I. j~ No tumor had "neural or glial appearance" as was stated by Nickel and Reed, z nor could arteriovenous anastomoses 5 be found. It thus appears likely that the Koenen tumor can be considered a particular type of fibrokeratoma that, according to Pi6rard and Lapi6re, 9 originates from the reticular dermis. Yasuki, 7 who studied the acquired periungual fibrokeratoma, distinguishes a type 1 lesion involv-
ing the nail plate and a type 2 lesion in which the tumor is derived from the periungual area; he considers that, like the acquired periungual fibrokeratoma, the periungual fibroma can be classified according to the topographic anatomy of the nail. In his opinion the periungual fibroma corresponds to the type I-acquired pefiungual fibrokeratoma and could be derived from the ventral aspect of the proximal nail fold, from the dermis beneath the matrix, or from the nail bed. In our material only one tumor type was observed--namely, a first-type lesion originating from the connective tissue located above the matrix. No lesions originated from the dermis beneath the matrix nor f r o m the nail bed. If the pefiungual fibroma is considered a particular type of fibrokeratoma, this tumor can be subdivided according to its clinical appearance, its location, and its origin into the following classifications: 1. Fibrokeratomas originating from the dermal connective tissue. These are posttraumatic or appear spontaneously and are located on the fingers (acquired digital fibrokeratoma). 2. Fibrokeratomas originating from the proximal nail fold or the surrounding connective tissue. They are located in the nail fold and can be congenital (tuberous sclerosis) or acquired (for example, garlic-clove fibroma). The close connection of the periungual fibroma with the proximal nail fold explains its particular clinical appearance.
372
Journal of the American Academy of Dermatology
Kint and Baran
W e thank Dr. Verret (Angers) for p r o v i d i n g o n e of the tumors u s e d in this study.
REFERENCES 1. Baran R, Dawber RPR. Diseases of the nails and their management. Oxford, England: Blackwell Scientific Publications, 1984:410-1. 2. Nickel WR, Reed WB. Tuberous sclerosis. Special reference to the microscopic alterations in the cutaneous hamartomas. Arch Dermatol 1962;85:209-24. 3. Rogers SR. Dermatologic manifestations, ha: Gomez MR, ed. Tuberous sclerosis. N e w York: Raven Press, 1979:114. 4. Klingbeil M. Ausgedehnte Fibromatosis sub- und periungualis bei Morbus Pringle. I--Iautarzt 1956;7: 360-2.
5. Knoth W, Meyh6fer W. Zur Nosologie des Adenoma sebaceum Typ Balzer, der Koenenschen Tumoren und des Morbus Bourneville-Pringle. Hautarzt 1957;8: 359-66. 6. Kawamura T, Nakauchi Y, Mori S. Beitrag zur Pathogenese der Bourneville-Pringleschen Phakomatose. Hautarzt 1964;15:476-82. 7. Yasuki Y. acquired periungual fibrokeratoma. A proposal for classification of periungual fibrous lesions. J Dermatol (Tokyo) 1985;12:349-56. 8. Hornstein OP, Weidner F. Tumoren der Haut. In: Schnyder UW. Histopathologie der Haut, tell 2: Stoffweckselkrankheiten und Tumoren. Bedim Springer, 1979:250. 9. PiCrard GE, Lapi~re CM. Nevi of connective tissue. A reappraisal of their classification. Am J Dermatopathol 1985;7:325-33. 10. Kint A, Baran R, De Keyser H. Acquired (digital) fibrokeratoma. J AM ACAD DE~A'rOL 1985;12:816-21.
ABSTRACTS
Cutaneous blastomycosis as a complication of transthoraclc needle aspiration Carter RR 3d, Wilson JP, Turner HR, et al. Chest 1987;91:917-8
cyte reactions showed similar interference by laser irradiation. The authors speculate that the hazards of low-energy laser irradiation to humans may be similar to the subtle modifications in biologic function they note in vitro. Jay A. Levin, M,D.
Implantation into the skin of the yeast form of blastomycoses reliably will cause a cutaneous lesion. Philip C. Anderson, M.D.
Two-step photoactivation of porphyrins with nanosecond red pulses
Epidemiologic study of canine blastomycosis in Wisconsin Archer JR, Trainer DO, Schell RF. J Am Vet Med Assoc 1987;190:1292-5
The recent epidemic of blastomycosis in Wisconsin has not been limited to humans. From 1980-1982, 200 cases of blastomycosis in dogs came under study. Cough, lethargy, and loss of weight are the usual early signs. Wherever canine hlastomycosis occurs humans will become infected, probably both groups from the soil, not from each other. Philip C. Anderson, M.D. Laser modulation of human immune system: inhibition of lymphocyte proliferation by a gallium-arsenide laser at low energy Ohta A, Abergel RP, Uitto J. Lasers in Surg 1987;7:199201 Cultured human lymphocytes were subjected to low energy gallium-arsenide laser irradiation. Cell proliferation measured by tdtiated thymidine was markedly inhibited by energy fluence as low as 10.85 mjoules/em2, as was mitogenic proliferation after pb.ytohemagiuttinin stimulation. At this energy fluence the viability of the ceils was unaffected. The functional immune response of human lymphocytes in response to antigen stimulation by one-way mixed lympho-
Andreoni A, Cubeddu R, Suelto O, Canti G, Ricci L, Smilquiavitchious V. Lasers Life Sci 1987;1:213-8 Laser-induced photochemotherapy for malignancies holds much promise for ouercoming limitations in the formation of cytotoxic photoproducts from porphyrias. Unfortunately, difficulties remain. The authors overcome problems with low energy and poor depth of penetration by using two pulsed excimer pumped-dye lasers tuned at 631 and 700 nm. The two-step excitation of hematoporphyrin derivative then allowed a higher ceil killing rate of murine fibrosarcoma tumor. This new technique would allow penetration of large tumor masses as well as superficial lesions. Jay A. Levin, M.D.
Genetic and diagnostic significance of HLA markers in sarcoidosis (German text) Nowack D, Goebel KM. Schweiz Med Wchnschr 1986;116:1479-80 Sixty-seven patients with histopathologically proved sarcoidosis were tested for human lymphocyte antigen (HLA) markers. The only marker that was significantly increased was HLA-DR5 (49.3% for sarcnid patients versus 21% in controls). HLA-DR5 carriers have a risk of developing sarcoidosis 35 times greater than patients without this marker. Yehudi M. Felman, M.D.