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Histogenesis of the granular-cell myoblastoma
Oral pathology GENERAL SECTION
Histogenesisof the granular-cell myoblastoma Y&i.& D. Toto, D.D.H., MS., curd Joacyh Kestarski, D.D.S., W.S. Chicago, IIt. DEPARTMRNT SCHOOL,
T
OF ORAL, PATHOLOGY,
LOYOLA
UNIVERSITY
OF DENTISTRY
hc granular-cell myoblastoma, first described by Abrikossoff’ in 1926, is founcl in the oral cavity of both the newborn and the adult. The lesion grows to the size of a pea. Stout? has reported sixteen malignant myoblastomas; however, most. myoblastomas are benign. Fust and Custer3 described the granular-cell myoblastoma as neurogenir. since they observed many such cells in degenerating nerve fiber bundles. Gray and Gruenfeld4 and Ewing5 considered the tumor to be composed largely of degenerating striated muscle. Murray” found skeletal muscle cells in tissue cnltures of granular-cell myoblastoma. R.atzenhofer,’ however, presented cvidencc suggesting the autonomic nervous system as the origin of the tumors. Bauer” considered the tumor to be essentially of fibroblastic origin, wherenq Wegnlin” beliercd bhat the tumor cells were of mesenchymal origin. Pearse’O and Toto and Restarskill presented histochemical cvidencc showing t.he presence of lipids in t.hc, cytoplasm of the granular cells. Tt was further shown that the source of the tumor cells appeared to bc pcrivascular. Furthcrmore, the cells appeared to differentiate first into fibroblasts before undergoing a granular degeneration. The growth of the tumor cells in the connccbivc t.issnc of the oral mucosa causes a degeneration of collagen and, when present, striated muscle also. The reports concerning the origin of the granular-cell myoblastoma. clea.rly show that the tumor does, in fact, arise in different connective tissues. In the oral cavity, the congenital granular-cell myoblastoma. may arise in the fibrous connective tissue of the mucosa overlying t.he ridge of the ,jawbono, which is fret! of striated muscle. On the other hand, it may arise in the tongue. The tumor also arises in the skin; Nora and associates’2 reported on bronchogenic granular-cell myoblastoma. 384
IIistogenesis
of granular-ccl.1
ntyoblaston~a
385
The observations generally lead one to conclude that, the granular-cell myoblast,oma is essentially a tumor of connective tissues. Also, mitotic activity in t.lx granular-cell myoblastoma must be rare, as reports do not. mention it. In order t,o dctcrmine the tissue of origin of granular-cell myoblastoma, we have reviewed six casesinvolving oral lesions. MATERIALS AND METHODS
Sections of formalin-fixed, paraRm-embedded specimens of granular-cell of the oral cavity were prepared. The sections were stained with hcmat.oxylin and eosin, Sudan B, black, aldehyde fuchsin, alcian blue, 2$‘dihydroxy, -6,6’-dinaphthyldisulfide (D.D.D.) , methyl green-pyronine, periodic? nc*id-Schiff (P.A.S.), diastasc followed by PAS. st.ain. myohlastoma
RESULTS
The histologic findings are summarized in Table I. The tumor cells contain granules which react weakly for the presence of neutral and acid polysaceharides. but there is no glycogen in the tumor cells. There is evidence of sulfhydryl groups in the granules, as seen with the D.D.D. reaction. There is no rihonucleic acid in t.he granules. Few mitotic figures were seen in the perivascular areas, in the endomysium, in the pcrincurium, or in fibrous connective tissue (Fig. .I) . The tumor cells proliferated in the endompsium, causing the striatc4 mus(hlt! fibers to separate and undergo sarcolysis (Fig. 2). The perineural loose connective tissues wcrc replaced completely by tumor cells. Also, the supporting cells of the peripheral nerve tissue showed tlegenerution (Fig. 3). The dense collagcnous fiber bundles in the lamina propria of the oral mucosa were largely replaced by tumor cells. Few residual strands of collagenous fiber bundles remained (Fig. 4). DISCUSSION
The grt~~rnlar-cdl myoblast.oma of the oral cavity arises in the perivascuhn loose connective tissues. The loose connective tissue is a rich source of undifferentiated mesenchymal cells. Such cells proliferate in the perineurium, entlomysium, and fibrous connective tissue. As they increase in number, the tumor cells could compete with the mature connective tissue for nutrition. As a consequence, there is a degeneration of muscle, fibrous connect.ive tissue, and Table I stain P.A.S. P.A.S. and diastase Alcian blue Aldd~yde fuchsin n.n.1,. Metllyl
1 Granules 1 + + k + -
Significance Weak polysaccharides No glycogen Weak acid polysaecharides Weak acid polysaccharidt~s Rllfhydryl groups No ribose nucleic acid
KF’. .I
P
Ii xl
Fiq.
3
Pi,
perineural tissue. This accounts for both the granules of the tumor cells and the gra.nular cytoplasm seen in t.he rlegencratin g cells of niusc.lc, pcrinenral cdls, a.4 fibroblasts. The involvement of ncrvc fihcr bundles, striated muscle, ancl fibrous connective tissue in the granular-ccl1 myoblastoms of the oral cavity supports t.hc multiple sites of origin of the t.umor as reported in the literabure. It. is evident? however, that the common denominator of all such t.iwucs is the ubiquitous loose connective t.issucs. In pa.rticular, it. appears that t hr granular-d1 myoI)lWt~OITlil is itn immature granular wl I clcriwd from rnc~Hclncli!-lnc~. 11. Novak, I)cpartment of Pathology, C!uok We acknowledge the assistawe of Dr. G. (!ounty Hospital, (‘hirago, 111. and t,ho contribut.ion 11y him of tissues used in this study. REFERENCES
1. Abrikossoff, A.: fibor Myomc, ausgehcnd von der qucrgestmiften willkurlil~hen Muskulatw, ,4rch, path. Anat. 260: 215233! 1926. 2. Stout, A. P.: Tumors of Soft Tissues (Atlas of Tumor Pathology, Sect. 2, Faw. 5 )? Washington, 1953, Armed Forces Institute of Pathology. 3. Fust, J. A., and Custer, R. P.: On Neurogenewis of So-c!alletl Granular Cell Myoblastomas, Am. J. Clin. Path. 19: 522-535, 1949. 4. Gray, S. H., and Gruenfeld, Am. .J. (Iancer 30: 699-708, 1937. G. IL: Myoblastoma, Disease, Philadelphia, 1931, W. H. Saunders Company. 5 Ewing, a.: Keoplastic 6: Murray, M. R.: Cultural Characteristics of Three Granular-Cell Myobla.qt.oman, (!ancrr 4: 857-865, 1951. M.: Granulare falsche Neurome (sag. ~lyolJlastennl?-onle) uml rekun~lare 7. Ratzenhofer, invasive Wucherung des Deekanepithels, Arch. path. Anat. 320, 138-163, 1951. 8. Rauer? w. H., and Rauer, J. I).: So-called Congenital Qulis, OKAL HI:R(:., ORAI. I\Isu. & ORAL PA!LW. 6: 1065-1071, 1953. 9. Wegelin, C.: Die Natur der sag; ~~~oblastelituliiorell, Rtbhweiz. Ztschr. allg. Path. IO: 631-653, 1947. A. 0. E.: The Histogenosis of Granular-Cell Myol,lastoma, J. Path. & Sact. 62: 10. Pearse, 351-302, 1950 11. Toto, P. iI., ind Restarski J.: Granular-Cell ~‘i~~rolJlanto~lItl, OKAT. S;icRo., OKAL ~~IF:II. & ORAL PATH. 15: 450-453, 1986. (‘ell Ilyol~lastoma of the jjron. 1“3. Xora, P., Novak, G. M., and Holmes, 0. \V.: Granular thus, J. Int.ernat. COIL Surgeons 35: 653-658, 1961.
Histogenesisof the granular-cell myoblastoma Y&i.& D. Toto, D.D.H., MS., curd Joacyh Kestarski, D.D.S., W.S. Chicago, IIt. DEPARTMRNT SCHOOL,
T
OF ORAL, PATHOLOGY,
LOYOLA
UNIVERSITY
OF DENTISTRY
hc granular-cell myoblastoma, first described by Abrikossoff’ in 1926, is founcl in the oral cavity of both the newborn and the adult. The lesion grows to the size of a pea. Stout? has reported sixteen malignant myoblastomas; however, most. myoblastomas are benign. Fust and Custer3 described the granular-cell myoblastoma as neurogenir. since they observed many such cells in degenerating nerve fiber bundles. Gray and Gruenfeld4 and Ewing5 considered the tumor to be composed largely of degenerating striated muscle. Murray” found skeletal muscle cells in tissue cnltures of granular-cell myoblastoma. R.atzenhofer,’ however, presented cvidencc suggesting the autonomic nervous system as the origin of the tumors. Bauer” considered the tumor to be essentially of fibroblastic origin, wherenq Wegnlin” beliercd bhat the tumor cells were of mesenchymal origin. Pearse’O and Toto and Restarskill presented histochemical cvidencc showing t.he presence of lipids in t.hc, cytoplasm of the granular cells. Tt was further shown that the source of the tumor cells appeared to bc pcrivascular. Furthcrmore, the cells appeared to differentiate first into fibroblasts before undergoing a granular degeneration. The growth of the tumor cells in the connccbivc t.issnc of the oral mucosa causes a degeneration of collagen and, when present, striated muscle also. The reports concerning the origin of the granular-cell myoblastoma. clea.rly show that the tumor does, in fact, arise in different connective tissues. In the oral cavity, the congenital granular-cell myoblastoma. may arise in the fibrous connective tissue of the mucosa overlying t.he ridge of the ,jawbono, which is fret! of striated muscle. On the other hand, it may arise in the tongue. The tumor also arises in the skin; Nora and associates’2 reported on bronchogenic granular-cell myoblastoma. 384
IIistogenesis
of granular-ccl.1
ntyoblaston~a
385
The observations generally lead one to conclude that, the granular-cell myoblast,oma is essentially a tumor of connective tissues. Also, mitotic activity in t.lx granular-cell myoblastoma must be rare, as reports do not. mention it. In order t,o dctcrmine the tissue of origin of granular-cell myoblastoma, we have reviewed six casesinvolving oral lesions. MATERIALS AND METHODS
Sections of formalin-fixed, paraRm-embedded specimens of granular-cell of the oral cavity were prepared. The sections were stained with hcmat.oxylin and eosin, Sudan B, black, aldehyde fuchsin, alcian blue, 2$‘dihydroxy, -6,6’-dinaphthyldisulfide (D.D.D.) , methyl green-pyronine, periodic? nc*id-Schiff (P.A.S.), diastasc followed by PAS. st.ain. myohlastoma
RESULTS
The histologic findings are summarized in Table I. The tumor cells contain granules which react weakly for the presence of neutral and acid polysaceharides. but there is no glycogen in the tumor cells. There is evidence of sulfhydryl groups in the granules, as seen with the D.D.D. reaction. There is no rihonucleic acid in t.he granules. Few mitotic figures were seen in the perivascular areas, in the endomysium, in the pcrincurium, or in fibrous connective tissue (Fig. .I) . The tumor cells proliferated in the endompsium, causing the striatc4 mus(hlt! fibers to separate and undergo sarcolysis (Fig. 2). The perineural loose connective tissues wcrc replaced completely by tumor cells. Also, the supporting cells of the peripheral nerve tissue showed tlegenerution (Fig. 3). The dense collagcnous fiber bundles in the lamina propria of the oral mucosa were largely replaced by tumor cells. Few residual strands of collagenous fiber bundles remained (Fig. 4). DISCUSSION
The grt~~rnlar-cdl myoblast.oma of the oral cavity arises in the perivascuhn loose connective tissues. The loose connective tissue is a rich source of undifferentiated mesenchymal cells. Such cells proliferate in the perineurium, entlomysium, and fibrous connective tissue. As they increase in number, the tumor cells could compete with the mature connective tissue for nutrition. As a consequence, there is a degeneration of muscle, fibrous connect.ive tissue, and Table I stain P.A.S. P.A.S. and diastase Alcian blue Aldd~yde fuchsin n.n.1,. Metllyl
1 Granules 1 + + k + -
Significance Weak polysaccharides No glycogen Weak acid polysaecharides Weak acid polysaccharidt~s Rllfhydryl groups No ribose nucleic acid
KF’. .I
P
Ii xl
Fiq.
3
Pi,
perineural tissue. This accounts for both the granules of the tumor cells and the gra.nular cytoplasm seen in t.he rlegencratin g cells of niusc.lc, pcrinenral cdls, a.4 fibroblasts. The involvement of ncrvc fihcr bundles, striated muscle, ancl fibrous connective tissue in the granular-ccl1 myoblastoms of the oral cavity supports t.hc multiple sites of origin of the t.umor as reported in the literabure. It. is evident? however, that the common denominator of all such t.iwucs is the ubiquitous loose connective t.issucs. In pa.rticular, it. appears that t hr granular-d1 myoI)lWt~OITlil is itn immature granular wl I clcriwd from rnc~Hclncli!-lnc~. 11. Novak, I)cpartment of Pathology, C!uok We acknowledge the assistawe of Dr. G. (!ounty Hospital, (‘hirago, 111. and t,ho contribut.ion 11y him of tissues used in this study. REFERENCES
1. Abrikossoff, A.: fibor Myomc, ausgehcnd von der qucrgestmiften willkurlil~hen Muskulatw, ,4rch, path. Anat. 260: 215233! 1926. 2. Stout, A. P.: Tumors of Soft Tissues (Atlas of Tumor Pathology, Sect. 2, Faw. 5 )? Washington, 1953, Armed Forces Institute of Pathology. 3. Fust, J. A., and Custer, R. P.: On Neurogenewis of So-c!alletl Granular Cell Myoblastomas, Am. J. Clin. Path. 19: 522-535, 1949. 4. Gray, S. H., and Gruenfeld, Am. .J. (Iancer 30: 699-708, 1937. G. IL: Myoblastoma, Disease, Philadelphia, 1931, W. H. Saunders Company. 5 Ewing, a.: Keoplastic 6: Murray, M. R.: Cultural Characteristics of Three Granular-Cell Myobla.qt.oman, (!ancrr 4: 857-865, 1951. M.: Granulare falsche Neurome (sag. ~lyolJlastennl?-onle) uml rekun~lare 7. Ratzenhofer, invasive Wucherung des Deekanepithels, Arch. path. Anat. 320, 138-163, 1951. 8. Rauer? w. H., and Rauer, J. I).: So-called Congenital Qulis, OKAL HI:R(:., ORAI. I\Isu. & ORAL PA!LW. 6: 1065-1071, 1953. 9. Wegelin, C.: Die Natur der sag; ~~~oblastelituliiorell, Rtbhweiz. Ztschr. allg. Path. IO: 631-653, 1947. A. 0. E.: The Histogenosis of Granular-Cell Myol,lastoma, J. Path. & Sact. 62: 10. Pearse, 351-302, 1950 11. Toto, P. iI., ind Restarski J.: Granular-Cell ~‘i~~rolJlanto~lItl, OKAT. S;icRo., OKAL ~~IF:II. & ORAL PATH. 15: 450-453, 1986. (‘ell Ilyol~lastoma of the jjron. 1“3. Xora, P., Novak, G. M., and Holmes, 0. \V.: Granular thus, J. Int.ernat. COIL Surgeons 35: 653-658, 1961.